 Good morning from Stanford University. My name is Will Chu. I'm the faculty co-director of the Storage X Initiative. I'm also a professor in the Department of Material Science and Engineering. Welcome back to Storage X seminar series. This is our first seminar series in the year of 2022. So I've been laid a happy new year to everyone around the world. So to kick off 2022, I'm really delighted to be hosting this seminar with Professor Yi Twei. As most of us know, the battery revolution was started in the early 90s due to the requirements from consumer electronics, later on by mobile electronics and computers. And for the past 10 years, we have saw huge drivers from the electric vehicle market. And many of us are asking what is coming next and one of the key technologies driving battery innovations today is electric flight. And today we have gathered an exceptional cohort of innovators who are disrupting the electric aviation market, not only from the battery side, but also from the planes themselves. And one thing that is extremely important to recognize is that innovating for this very demanding market requires integration all the way from the battery materials to the battery cells, to the battery packs, and then to the planes themselves. And for that reason, we have invited three innovators to join us today to talk about all that and then try to link everything together. And we'll have three speakers, as I mentioned. First we'll have Richard Wang, who is the founder and CEO of Kuber. And Kuber is developing battery technologies at the materials level. And I'll let E introduce Richard just in a second. And then our second speaker is Herman Wiegman, who is the co-founder of Beta Technologies. And we have our third speaker, who is Omar Boyohai, who is the founder and CEO of EVation. So E, why don't you get us started? By introducing Richard. Well, thank you. I'd like to add my welcome to everybody into the new year. It's going to be an exciting one. Hopefully there will be a lot of in-person meetings we can do, but we will continue our symposium online to capture the audience worldwide. It is my great honor to introduce Richard Wang. The reason is Richard was my PhD student, really outstanding one. I remember Richard joining Stanford for graduate school after finishing in Caltech as a top student. He comes to the lab with the NDS-EG fellowship. And Richard and I talked in the work project he wants to work on. We set her on this open framework, pressure-brew type of structure. Well, Richard has done a number of seminar works to demonstrate this open framework could be very exciting as battery materials. Well, during this process, Richard always has interest to explore what's the really big impact he can make to the whole society. Well, Richard went out to do, well, he did an intern in Tesla. And then later together with my other postdoc, Mara Pasta, they cook on the idea, supported by Tomcat Center here at Stanford to start Q-Book. Later, these will also get incubated in the Cyclochon world a little bit more. Richard served as the CEO and really took Q-Book to the next level. Many of you have seen the recent announcement the acquired Q-Book by NorthWatt. Richard has been developing very exciting lithium metal batteries for high energy density applications such as aviation need. With that, Richard, I would like to take it from here, but let me mention one thing. Richard was the fourth, 30 and the 30 winner several years ago. That's very, very deserving honor, Richard. Take it from here, Richard. Okay, thank you, E, for the kind welcome and for everyone here for inviting us to this very exciting event. So I shared my screen, I'll get started here. So my name is Richard Wang. I'm the co-founder and CEO at Kubrick. As E mentioned, we spun out of Stanford in 2016 and developing a lithium metal batteries for electric aviation. So just the talk that I'm gonna give today will be focused a little bit about introduction to what Kubrick does in terms of our technology and product and then really focused on our perspective on what it takes to develop batteries for electric aviation and some of the learnings that we've come across in our experience working with our customers to really push forward on this field. So about Kubrick, as I mentioned, we're currently still based in the Bay Area. We haven't moved very far. We're in the East Bay currently in San Leandro and a new headquarters that we just moved into. Working on a lithium metal technology, which I'll describe in greater detail later, we see advanced air mobility as really being the key driver of battery innovation, but ultimately also as a stepping stone towards much larger volume markets in the future, such as automotive and elsewhere. As E mentioned, we were acquired by Norfolk back in March, 2021. And we're incredibly excited about what this partnership means for the industry and in particular, I think what we can really do together with Norfolk to make a true impact and deliver a valuable product for the air mobility industry. And so very quickly about Norfolk, it is a Swedish startup founded in 2016 by a couple of ex-Tesla supply chain executives, Peter Carlson and Paulo Truti. They are currently now 2,500 people based in Stockholm, as well as building gigafactories in far Northern Sweden, as well as Germany. Now looking at additional expansion plans beyond Europe as well. Principally focused on automotive markets with large customers like VW, BMW, Volvo and so forth, but also have products in the grid and industrial sectors. I think at this point $50 billion in revenue has been contracted already. There's much, much demand for lithium ion batteries these days and I've raised $4 billion in equity funding so far. And one really notable thing which I'll keep coming back to later is that Norfolk is I think one of the first sell manufacturers to really become fully vertically integrated from upstream raw materials through to making their own active materials through to making their own prismatic and cylindrical cells and then also doing a module and system design as well as end of life cell recycling all under one roof. And I believe this will come really to become a model for the battery industry but even more so for the air mobility sector. And so with Norfolk's, we have a pretty unique responsibility here. Three main areas. One is to serve as Norfolk's advanced technology center in Silicon Valley. This is really a technology scouting and open innovation role to work with the leading innovators from universities like Will and E as well as the exciting startups in the area to really figure out how do we think about corporate partnerships in the most effective and savvy manner of working with these companies to advance the state of technology. We are of course focused on pushing forward our current, our next gen battery technology focused on liquid electrolyte with lithium metal cells and really building out the aviation business unit on behalf of Norfolk as the first market for lithium metal cells. So just a little bit since this is a battery talk about what we do here at Kubrick and honestly, I do see this type of approach as being the most likely type of cell architecture to get commercialized for air mobility. Essentially, we have replaced the graphite anode in the lithium ion cell with a much, much lighter weight lithium metal anode. And the lithium is ultimately the lightest anode material that you can use on the periodic table provides exceptional specific energy and power which is exactly what you need for air mobility to make lithium metal work because it's a very, let's say sensitive and reactive material. We have developed a new non flammable liquid electrolyte to stabilize this anode and enable good cyclability and reliability. This is in contrast to a lot of companies these days that are developing solid state electrolytes where instead of using liquid they've really changed completely the architecture of the cell to use a solid membrane as the separator and the electrolyte for ion transport. While it has, I think some interesting benefits one of the main challenges here with a solid state approach is that it's not really easily compatible with the existing lithium ion manufacturing processes. And so really the benefit of using this liquid electrolyte system is that you can integrate it into existing factories and scale it up much faster and more reliably compared to other technologies out there. And in particular, this really is our vision with Norfolk. Like to really fully leverage our partnership with Norfolk and leverage their manufacturing capabilities the more that we make this compatible with the processes they're already running in their gigafactory today, the faster we can really scale volumes and economies of scale to drive and deliver a compelling product here. Other than the electrolyte and the lithium metal the rest of our cell is actually quite standard. We use a standard polyolefin separator lithium ion separator as well as a standard nickel rich NMC cathode material essentially the same cathode material that Norfolk already uses today in their automotive products. And so you can see it really does leverage to a substantial extent the supply chain and the maturity of a company like Norfolk but really focused on making innovations where it really matters on the lithium metal element on the liquid electrolyte. And so the two segments where we really see lithium metal cells taking off are an advanced air mobility which is the focus of this talk and then a high performance automotive applications which I'll briefly touch on advanced air mobility. There's quite a few different applications which I'll talk about a little more later but this includes both fairing people as well as cargo around in various different ranges and configurations. It's very, very sensitive to specific energy and also to specific power given a takeoff requirements especially for vertical takeoff but it's not so sensitive to fast charge performance. On the other hand, I think lithium metal will also enter the automotive sector but you're not gonna see it initially and let's say your mass market sort of model three or ID four kind of vehicle. It's gonna start out most likely with sports cars, premium SUVs and then really I think long haul heavy duty trucking being one of the primary automotive users. These are segments, the trucking in particular that are quite difficult to electrify because of weight limitations on trucks. And so the weight savings of lithium metal cells will actually be quite important enabling that whole segment. And this is an area that we see coming online a little bit later than air mobility because of the cost sensitivity as well as sensitivity to fast charge but at the end of the day, a very achievable target as well for lithium metal. And so the two companies here with me today are beta technologies and aviation. And so I will let them talk about their projects as they come up. But as illustrative examples of what this market looks like broadly defined, you have two classes of aircraft. One is EVTOL which is electric vertical takeoff and landing. So you take off vertically and then transition to horizontal flight for cruise efficiency and then land vertically as well. And this is because you have significant advantages in terms of where you can take off and land and the flexibility of your operations. And these are envisioned to be used for air taxi and regional air mobility applications to ferry passengers around very cost effectively as well as cargo and transport applications. Aviation is working on what's called an ECTOL aircraft. And this is conventional takeoff and landing. And this is something that essentially looks like a existing plane but with really optimized for batteries and electric propulsion and for cruise efficiency but essentially it'll use a regular airfield takeoff horizontally, fly horizontally and land horizontally as well. So this kind of aircraft in many ways is somewhat easier to certify because it is more similar to existing aircraft that are already in operation today. And particularly will be I think quite impactful in the regional air mobility market to take passengers around at very low cost. And so our vision for why I think air mobility is such a unique driver of battery innovation. You know, the more I see in this industry the more I'm convinced of this hypothesis. And I'll talk more in detail later on some of the numbers about exactly why it is but at a high level you can really just think about it as flying objects are extremely sensitive to weight and any kind of weight that you can shave off of a vehicle is profoundly important in terms of the types of aircraft you can design, the passengers and cargo you can carry and really even the business models that you can enable with air mobility. And so there's such a strong drive for lighter weight batteries that it really you have this very strong push and very strong partnership with the customers to push forward on battery innovation. The companies in the sector also happened to be very technically savvy and nimble with beta and aviation as two great examples. And so really they are pushing the envelope both on aircraft design as well as on a next gen battery technology. They're not afraid to make a bet on better technology if they really see the value and the reliability there. It's also a super rapidly growing and high margin business. And so because it's much less competitive and commoditized compared to other battery markets for very good reasons, but because it is less commoditized, this is a more sensible first entry point for new technologies that typically will take some number of years to scale up in maturity and volumes to drive economies of scale. It's not a great model to immediately try to jump towards a mass market automotive application because you're gonna lose a whole lot of money trying to pursue this kind of cost sensitive industry. And so air mobility, I think for all these reasons is a super strong driver for battery innovation these days. I do see air mobility as being a stepping stone towards driving automotive integration of lifting metal cells as well in a fairly quick way, but I would say it's maybe two or three years later in commercial adoption compared to air mobility. Automotive customers are really slower adopters and not intrinsically because the companies are slow, although maybe some of them are as well, but because the value proposition for energy density is not nearly as high. I would argue it's actually one to two orders of magnitude lower in terms of the value proposition they derive from energy density compared to what air mobility derives from energy density. And by having an early market, we're able to really demonstrate the capabilities that we have, this then allows us to accelerate and de-risk the adoption of this into the automotive market without really needing to sort of subsidize the developments and subsidize the scale up until it gets to a point where it actually can stand out its own to feed in automotive. And so I'm gonna start, I think, diving now into some of the unique dynamics that I see for the industry. But one final point here is that we are really in very, very close partnership with Norfolk. And I think as you'll see in the following pages, this kind of an integration is absolutely critical in terms of success in the advanced battery sector and particularly for air mobility. And so with Norfolk, we're actively working with quite a few teams across the board, certainly in terms of materials like cathode and separator. But I think even more critically in terms of model developments and systems integration work, to really understand how do ourselves get into a system and ultimately into a certified aircraft, as well as beginning a collaboration on their recycling capabilities. Ultimately, when we can offer this really true portfolio of offerings to air mobility customers is really when you'll see this industry take off and have batteries that really can go all the way in terms of serving the needs of this market. So first, looking at a cell level requirements for air mobility, I would argue based on what I've heard in the industry that most customers are pretty happy if you can get to roughly 400 watt hours per kilogram at the cell level. Of course, everyone would always want more specific energy, you could never have enough. But what we see is if you get to about 400 of the cell level, 300 at the module level, you're at a point where a lot of the early business models and applications are enabled and can be done with aircraft designs that are currently early in test flights today. This represents roughly a 50% increase from the best kind of lithium ion modules these days, which are at about 200 watt hours per kilogram for aviation grade modules. So literally a 50% increase in how much you can fly. EC tall conventional take off has, I would say moderate power requirements, nothing crazy. Maybe something up to like one and a half C or two C for a few minutes at take off. And then you're really kind of cruising and using the lift of your wings for a very, very efficient cruise. So maybe 0.5 C or even a little lower 0.3 C for cruise. E V tall because of the vertical take off nature has much higher power requirements. I would say E V tall is a much more diverse set of aircraft designs. So there isn't kind of a one size fits all set of numbers for what E V tall requires. But roughly speaking, probably on the order of four or five C for 60 to 90 seconds for a take off. And then sometimes you actually need to pulse up to eight C for one to two minutes for emergency landings, which I'll talk a little bit more later about why that's needed. But really that this is part of really having a redundancy in aircraft, even if you have one entire module or pack go out of service, you still need to do emergency landing. So very, very rigorous power requirements. And then cruise is much more efficient, maybe one C, 1.5 C, depending on the efficiency of the aircraft. But you can see these numbers. I mean, these C rates are high, but what makes it even more difficult is these are C rates assuming a 400 watt per kilogram cell level. So when you multiply the C rate by the greatly higher specific energy at the cell level, you're really talking about very, very high levels of specific power watts per kilogram. And only if you look at the lithium ion industry, only the very, very highest power kind of pouch cells can actually hit these kinds of specific power requirements. But the cells that are designed for such high power with lithium ion end up having specific energy of 200 watt hours per kilogram or lower even at the cell level, like 200, 220 watt hours per kilo for high power cells. So using the lithium metal chemistry allows you to use a high power design, high power cell design, while still achieving really high specific energy. And it's really that combination of high energy and power that delivers what you need for air mobility. In terms of use cases, fast charge is not nearly as critical as automotive where everyone is saying they wanna get the 3C, 4C and beyond fast charge with air mobility. Typically what we find is when you get to sort of the 1C, maybe 1.5C charge rate, this is enough for most of the early business models. Maybe not when you're kind of super optimized and flying around in cities, but right now this is likely sufficient. Given you do need to turn the aircraft around, load and unload your passengers cargo and clean the aircraft and so forth. And the other piece of this is you're not actually sitting on the ground for a full hour charging at 1C, because the typical depth of discharge is maybe 50% or even less for most aircraft designs. And the reason for this is really from a certification requirement basis. You have essentially flight reserve requirements where from FAA and YASTA saying you need, for example, 20 minutes of flying time so that you can fly to the nearest kind of emergency landing site or airfield. And so that kind of requirement, when you look at the percentage of flight time that that takes, it ends up being you need to really reserve a good amount of reserves, both for the flight reserves, as well as a buffer for SOC and other kinds of design redundancy. So DOD is pretty low. So even a 1C charge at 50% means you're on the ground for half an hour max. That's why fast charge is not so critical for this industry. Cycle life as well, everyone wants more cycles, but I would say when you get to about the thousand full depth of discharge normalized cycles is sufficient for many of the early applications. This is going to be kind of a both cycle life and cost parameter, but cycle life is important, even setting aside a unit economics because the packs are utilized to such a high love, high degree. You're basically trying to fly these aircraft continuously as much as possible and with very demanding profiles. So estimates are every six to 12 months, these packs will need to be swapped out from the aircraft for new packs. And this actually has quite a few implications, both in terms of module and system design, as well as in what kinds of capabilities and business models from a battery provider really makes sense to serve these use cases. In terms of, let's see, cell design and form factor, we have done a lot of thinking and also a lot of discussions with many different customers around the world on what really is needed for an optimal, let's say product for air mobility. And then I've at least settled, my conclusion is that a pouch cell is the best type of cell for air mobility. And with a capacity of maybe 15 to 25, maybe 30 amp hours being like an ideal size. The reason for this is that you basically, you want large cells because larger cells allow for better packing efficiency. This is why in automotive systems, Tesla aside, most companies are looking at 70 plus amp hour pouch cells, even 100, 120 amp hour prismatic cells. And the reason for that is they're trying to reduce the pack overhead and the packaging overhead associated with their system. On the other hand though, the air mobility has much more stringent safety requirements compared to automotive, specifically in terms of cell thermal propagation. And so because you really need to be intrinsically propagation resistant from a module and pack perspective, this means that really, really enormous cells are not a great bet because it becomes very, very hard to contain that thermal runaway. So that's why we believe ultimately kind of this 20 amp hour zone to be a sweet spot, balancing packing efficiency with thermal propagation considerations. You can also ask why not cylindrical, why not prismatic? Cylindrical cells lack the power capability typically you can also get high power cylindrical cells, yes, but sort of a order of magnitude, you have this very, very long foil, it's a wound electrode with a long conduction pathways and high electrical resistance with something like the Tesla 4680 concept that's tabless that takes care of a lot of this. So you could in theory get very high power out of that kind of cell if designed for high power applications. But the other challenge of cylindrical cells is they don't accommodate next gen chemistry very well because of the wow nature. It doesn't tend to do very well with very high silicon content or lithium metal anodes because of the swelling and pressure requirements that are more unique to next gen chemistries. And then finally prismatic cells, I think will just be too heavy because prismatic cells work well when you're at this kind of 70, 100 amp hour plus size but the packaging is pretty heavy. And when you try to scale it down to a cell that's 20 amp hours, you just have too much packaging overhead and weight overhead. So this is why I think nobody has really seriously considered prismatic cells in terms of permeability aircraft. And then specific energy I think is absolutely critical. And I think some back of the envelope math here is actually very illustrative. An EV tall, let's say it costs $15 per miles not including the batteries to operate. This includes pilot maintenance, kind of everything else embedded in that cost. This is kind of a middle of the road figure from a few studies I've looked at. If you look at basically kind of battery cost and size typically 250 kilowatt hour pack multiplied by some dollars per kilowatt hour and your plane is carrying some number of passengers. Let's say it's 200 miles if you went 0 to 100% SOC, 1,000 cycles like reasonable assumptions on what this would look like. If you look at a lithium ion scenario, you plug in some numbers, 200 watt hours per kilo at the pack level. You get to basically a pack that's let's say 1250 kilograms conservatively. Even if we say it's a super cheap automotive kind of cost pack $100 per kilowatt hour, if it carries three passengers the battery is gonna be a minute fraction in terms of passenger miles, four cents per passenger mile but the total cost of operation is $5 four cents per passenger mile because you're dividing that $15 by three people. And really where specific energy comes in is when you can have a lighter pack 300 watt hours per kilo you're saving more than 400 kilograms here in terms of battery weight. And so even if you assume it's $1,000 a kilowatt hour 10 times more expensive the key thing is if you're saving 400 kilograms you can probably carry one or two extra passengers plus cargo plus aircraft overhead. And then even $1,000 per kilowatt hour battery cost is not crazy 25 cents per passenger mile but your total cost of operation goes down to $3.25 per passenger mile. So the key takeaway is that it's much more important to increase specific energy because this allows you to carry more cargo and more passengers to defray your overall operating costs because batteries are not the biggest or nearly the biggest cost driver in the sort of build materials and driving economics for air mobility. So you could actually say, you know if you run the numbers like side by side like increasing specific energy is worth something like $8,000 per kilowatt hour. Like this is good, you know maybe it's 5,000, maybe it's 10,000 but the key thing is this is why specific energy is absolutely so critical for air mobility. The other two I think unique considerations here are that aircraft certification is one of the most difficult things in this industry and represents a key risk to timelines. I think nobody doubts this industry will become enormous eventually but we don't exactly know when yet. And so supply chains and production from a battery manufacturer perspective it's very different from a standard supply chain consideration for automotive cells. You need much stricter process controls for all production processes, traceability to your key materials and production lines that are purpose designed for airspace quality and traceability standards. You need to design your modules to be DO311A compliant. This is the current safety standard for flight batteries but designed for things like, you know the battery on the 787 not for propulsion batteries but this is the best we have so far on what regulators might consider for battery safety and essentially you need a pack to withstand single or multi-cell thermal runaway while preventing full propagation and still being able to do emergency landing. But the details of this certification pathway at the module level really have not been fully determined and that's one of the big I think unknowns in terms of what it takes to actually get batteries into these systems. And then in terms of geographies and aircraft types this is getting beyond really my core area of expertise but broadly speaking there's kind of different certification levels depending on what type of aircraft you're building. And so most companies are looking at part 23 which is small aircraft smaller than 19,000 pounds or 19 passengers or part 27 like a helicopter for EVTOL and these have an accident rate that's acceptable by FAA of 100 parts per billion. The AFSA is considering regulating EVTOL sort of more similarly to a commercial airline or level of reliability one part per billion accident rate and this actually can have a substantial impact in terms of timelines and costs to actually get to market. And so nothing has been finalized which is either the uncertainty is challenging to design around but really different geographies are considering doing this in different ways which will impact where you see early uptake in terms of air mobility adoption. And then finally I think vertical integration is absolutely critical for success. One of the things that I've really come to realize is that a standardized pouch cell format it has huge benefits. The reason for this is that it's very expensive and slow to certify an air mobility cell and module because of all the requirements I've just mentioned and volumes per aircraft are also much, much lower compared to any kind of automotive volumes for the foreseeable future. People are not buying tens of gigawatts of cells anytime this decade from a single customer. And on the other hand structural integration I would say is less critical compared to automotive because you cannot literally just embed it into your aircraft. There has to essentially be some sort of maintenance bay that you can open and swap out aircraft and basically blocks of batteries that come in and out. And given this, it's not so critical to have this perfectly designed flat pack battery for example, you have sort of more flexibility to accommodate different kinds of cell geometries. And so cell standardization ultimately is actually a viable solution in this industry that ultimately will give us much better cost control and economies of scale compared to having custom cells for every single aircraft. This directly feeds into systems integration. My view is aircraft developers should have need to design their own custom module that they should standardize if possible. And next gen chemistries present pretty unique challenges for model design. So this is I think one reason why cell developers should take it upon themselves to design their modules as well because you really need to know the cell well to design the module and certification costs. Again, costs and timelines can be defrayed if you can use one common module for all aircraft. And then finally integrated data systems are also needed to ensure reliability and optimization of batteries to maximize cycle life. So you need a whole lot of systems engineering beyond just having a good cell to really succeed in this market. And then finally, I would say you really need the full scope from upstream to downstream in terms of raw materials, supply chain traceability and control as well as looking at second life opportunities. These battery modules will be highly advanced and highly engineered. And we're not just gonna throw them away, of course, after they're done on the aircraft. And there are other great applications in which you can use second life. And then ultimately you need to take care of recycling. So there's a whole lot of things that we need to figure out in this supply chain to make this battery industry work well for our customers. And ultimately I would argue the most reasonable and elegant solution to do this is to have really a supplier take care of all these different responsibilities be an end to end supplier of energy for aircraft at the end of the day and take care of all the kind of considerations from beginning to end of life in terms of managing these technologies. I think this ultimately will be the most reliable way for companies to deliver high quality batteries. But it also does mean that this is a very difficult market to enter, to be honest. Without this kind of vertical integration, even if you have a great cell, it's gonna be pretty tough to actually get into this market. So this is kind of the, I think, both the beauty and the curse of air mobility is it's an incredible value proposition and incredible industry with clearly a very high drive for innovation in batteries. But it's also not easy for a battery supplier to actually make it into the market here. And so you need to really focus in building this sort of holistic infrastructure and ecosystem to really deliver good products for air mobility. And so my kind of, I think sort of conclusion and takeaway message is I feel that the battery really is the jet engine of the advanced air mobility era. Just as jet engines have been absolutely critical to defining aircraft designs and even business models and economics and fuel efficiency, of course. It is even more the case that batteries are the defining technology for really enabling different kinds of business models and aircraft designs in the advanced air mobility era. And so I think just as jet engine manufacturers have such a close partnership with the key aircraft designers, it is our intent with North Pole and Cuba to really have that same kind of capability that we can deliver from a battery perspective for the air mobility era. So that's all I have to say. Happy to answer questions here. Well, thank you so much, Richa. This is very exciting. Maybe we will take a few questions only for now because we are going to have a panel discussion later. So, Richa, the first question is one of the person is asking, compared to lithium metal technology, what are the competing technology out there? For example, people talk about hydrogen fuel cells, right? There's also others like the silicon handle I'm very familiar with from Ampereus, you know, for the high-energy density battery they will be good to see your father on this now. Yeah, so I think first in the battery realm, other than, let's say, lithium metal, as how I've described it with liquid electrolytes, you have solid state batteries, but I think solid state has challenges for a number of reasons. Solid electrolytes are dense and heavy, so it's hard to get a specific energy and power that you get from a liquid electrolyte system. I think silicon is a possibility if you can really figure out very high utilization silicon anodes, which is by no means easy as well. But if you could figure out a really high utilization and high loading silicon, you could get to very high energy densities. So I think that's a possibility. You have lithium sulfur, but sulfur has many well-known challenges. We don't have many prominent sulfur plays these days with oxys going out of business a year or two ago. So I think sulfur is a little far off and the volumetric energy is very, very low, which makes it tough to integrate into an aircraft. And then finally, if you look at outside of battery technologies, I don't really see hydrogen or let's say synthetic fuels as being a direct competition to batteries. And the reason is that any kind of aircraft that you could fly with batteries is gonna be vastly more attractive to do with batteries than with hydrogen, because it's so much more efficient, both in terms of the systems you have to design as well as the fuel costs to use electricity and to use batteries. So where we see hydrogen and synthetic fuels coming in is not in these kinds of UV tall, EC tall short-haul aircraft, but really when you start looking at very large planes, 50, 100-seater and beyond, and trying to fly kind of 1,000 miles and beyond in range, that's where batteries really tap out and you look at those alternatives. Yeah. Maybe one more question here, which are for you. For Kilberg, the lithium metal batteries, what's the current status right now? The specific energy, cycle life and so on, so people are wondering how far you are. Sure, sure. We've been keeping a little quiet recently because when we go out with needs, we like to do it with third party independently validated results. So I don't like to make too many claims until I'm able to prove it as well. It's always a challenge in the industry. But to give a rough notion, currently we're developing a couple of different formats of cells. We have a five amp hour technology demonstrator where we integrate and demonstrate new approaches and materials. And then we have a couple of different commercial designs in the 15 to 25 amp hour range that we're actively testing with customers. This is more designed for actual module integration purposes. And specific energy wise, roughly 378 to 400 waters per kilogram, depending on the variant, getting pretty close to 400 with our newer gen stuff. And very high power, as I mentioned, very, very high power rates and then cycle life getting beyond five to 600 full depth of discharge cycles at this point. But again, I don't want to make too many claims for now. That's why we haven't been on public with the stuff. We'll hopefully release third party results in the coming one or two quarters. This is very nice, Richard. Thank you. I will discuss more in the panel discussion. Well, back to you. Let me add my thanks to Richard as well for that wonderful introduction and connecting the requirements at the level of the planes to the battery material requirement. I think this will be a very important thing for the seminar today. So it's my great pleasure then to welcome our next speaker. Herman, are you on the line here? Excellent. Well, Herman is joining us from the UK. So again, we have a very international audience and international presenters today. So thank you very much, Herman, for taking your Friday evening to join us. So Herman is a very richly decorated battery veteran. He spent, if I remember correctly, about 18 years at GE Global Research in New York where he led a variety of projects for energy storage, was an early innovator for sodium ion, a sodium sulfur-based battery technology and other sodium ion-based battery technology. And he touched upon a wide variety of applications from grit level to backup for telecom systems and many other things as well. So Herman saw these energy transition coming long ago and now he is leading the electric propulsion team at Beta Technologies. And Herman, we're super excited to hear from you both from a battery side and from a plane side, how these two are coming together. Herman, the floor is yours. Thank you, Will, thank you so much. And also Richard, for your excellent overview of the market and the energy storage needs. I'm gonna share a little bit more on the aircraft side. Talk a little bit about electric vertical takeoff and landing development, but also some of the energy storage testing challenges and making the storage system safe enough for flight or for aviation use. We're really looking for a sustainability goal to make electrified flights such that it's more sustainable from a carbon footprint point of view. We're also going after that vertical takeoff and landing aspect to get more use from the aircraft instead of just limited to airfield use. So vertical takeoff and landing, some people call it EVA, electric vertical aircraft, but it's really a new area and it's really initiated by the onset of distributed propulsion systems and the new advanced battery technologies such that Richard talked about. And so things are becoming more realistic. We're able to achieve flight of reasonable distance so the minimal viable product has been achieved and we see obviously many players in the field entering the EVTAL space. I think it's on the order of 400 companies have ideas and about 15 or so are making serious effort and progress. All right, who's beta technologies? We also don't like to over promote ourselves. We only like to release news when we're ready. That may not be the best approach in this hyper connected world of ours, but we are located in Vermont and this is a picture of our Lea aircraft and CETOL configuration flying over Platsburg, New York. Our focus is really to make elegant electric aviation solutions for our customers and they are obviously concerned with cost effectiveness, safety and also environmental impact. And our first customer is actually from the medical field where United Therapeutics was focused on producing replaceable organs and organ transplants. And they often found that they were transporting their organs from the creation site or resuscitation site to the patient through a lot of conventional technologies like helicopters and airplanes and trucks and ambulances. And they thought, gosh, you know, it's great if we can save the patient, but wouldn't it be even better in the process if we could also save the planet? Because you just save the patient, but not the planet and it's kind of didn't go well with them. So they really were an early adopter of EV-12 technology and really encouraged us through their use kicks. This is a picture of the team from about a year ago and our headquarters at Burlington International Airport. We do have the aircrafts in the background is the Aliyah aircraft in black carbon fiber. And you see some conventional aircraft as well because that's also part of our culture. We're about the same age as Kuberg in oddly Northvolt around this 2016, early 2017 is when we formed the company and started developing electrified aircraft solutions. We are pragmatic, focused on the core technologies and providing a total solution to our customers because it's not just the aircraft. There's many other aspects. We try to focus on those parts of the system puzzle as well. And flying is part of our culture. We encourage all of our employees to take lessons and here we're just doing a formation flight and it's great fun to hear all the employees talk about the aspects of the aircraft that they like which one are they flying a conventional Cessna or a tail-dragger or a higher performance aircraft or a stunt aircraft. And some people say, isn't that a waste? Why are you doing that? Why are you teaching your employees to fly? Well, would you buy a car from a set of engineers that didn't have driver's licenses? You have to think about that. So everyone in the country, the company is very much a part of the aviation culture and is passionate about it and that really helps when it comes to higher performing and safer aircraft. At Beta, we do focus a lot on first principles from an aircraft point of view and we have to make sure we do well in each of these four areas in order to make a truly honest and good performing aircraft. The empty weight really talks about the structure of the aircraft and the systems. That could be everything from the flight controls to the landing gear to the pilot seat but really it's dominated by the structure of the aircraft, the skin, the ribs, the spars. And we spent a lot of time making the empty weight as low as possible. The second really thing that we focus on is the energy storage. It's a significant portion of the weight of the aircraft roughly in the order of 30 to 40% of the weight of the aircraft is in better hands. So we really have to get the most from those and Richard did a great job talking about the specific energy density getting that north of 400 watt hours per kilogram at the cell level, such that when it's packaged maybe it might be then eroded to about 300 watt hours per kilogram. Those are good numbers to shoot for for a minimally viable product. Also, we can talk quickly about the power capability. Richard also mentioned the watts per kilogram are important as well, particularly at higher depths of discharge, lower states of charge in order to achieve those landings particularly in vertical flight. Efficiency is the third topic we would focus a lot on and that comes down to the power conversion efficiencies and for electric drive systems it's usually up in the 90 or so percent range and so we have to pay attention there. The last aspect is what's called L over D. That's lift over drag. So how good is the aircraft at producing lift? How efficient are the wings? And what's the drag of the aircraft? How elegant is it? And so we really have to pay attention to that. And simplicity is really a driver for us. Simplicity helps in terms of safety, in terms of failure modes, in terms of certification. I'm just gonna do a quick synthesis of our aircraft that we call the Aliyah platform. We start with the cargo, the pilot and putting that into a teardrop shape body or fuselage. It has to be volumous enough. We were given a challenge of a certain pallet system, a certain four foot by four foot cube and two operators, a pilot and or crew. And so that's how we started this concept. Then you have to make it fly. To do that, obviously adding the wings and tail and we added the efficient pusher propeller in the back. It helps with the ingestion of air across the fuselage. It's the most efficient place to put a propeller on a simple aircraft like this. Now that's great for cruise flight, but we also wanted to have the vertical flight component. What does that look like? Well, if you add a quadcopter to that original fuselage, this is what a vertical takeoff and landing aircraft could look like. We did go for a quad in this particular application and we wanted to have something that could have streamlined propeller blades during cruise flight. So when the lift system is not in use, we could just park them and have efficient forward flight. Putting those two concepts together ends up with the Aliyah aircraft. We're hoping to achieve 250 nautical miles of ultimate range around 105 knots. These are not very fast aircraft and hopefully less than one hour recharge. And that's the synthesis of a first generation electric vertical takeoff and landing aircraft. This is an actual view of serial number two aircraft that we have. And there's two variants, a cargo variant and a passenger variant that we're going to be developing. There are some other restrictions that were applied. Vertical takeoff and landing aircraft can land on helicopter paths and those are often restricted to 50 foot squares. And so the wingspan of the aircraft is somewhat restricted to the same 50 feet. Another goal is to keep it below 7,000 pounds and this gets back into the certification requirements. Aircraft below 7,000 pounds have slightly different set of rules than those above. And so those are sure the two constraints that will be driving the designs of many of these EV tall aircraft. But we talked about systems, it's not just the aircraft, you have to have a means of recharging it. And so we've been developing elevated recharge pad solutions, leveraging technologies such as the automotive recharge equipment. And we've also been operating and testing these various systems on our aircraft in winter, in Vermont where there's icing and snowing, right? So we're just learning so much and we're making tweaks and changes to these systems to go from, let's say, electric vehicle use to now aviation use. And so it's been a wonderful progression of learnings as we develop these recharging infrastructure. The other thing we're doing is really investing in the network. Because if you have one charger, that's great, you can take off and land from one airport. If you have many chargers, now you can actually fly somewhere. So what we have right now is about nine sites installed and about 51 sites in progress, either engineering plans made or ground has been broken. So we're progressing on this. All right, once you have an aircraft and you can recharge it and fly it, well, it takes a pilot, that takes certain training. We've been spending a lot of time doing flight training for this particular class of aircraft because it's not well documented in terms of pilotage requirements today with the FAA. They have things like helicopter pilots. They have multi-inching pilots, but they don't have electrified EV tall pilots. And so we have to come up with a curriculum and the testing standards and requirements in order to certify those air pilots to fly this class of aircraft. And so we've been doing a lot of work in that area. And there we go. This is serial number one, Aliyah aircraft. We're hoping to go through the FAA certification process. We have engaged and we've initiated that process, but it does take time to get from the proposal all the way through certification testing. We're not going to commit to that time frame. It's going to take as much time as necessary to assure that the aircraft is safe for use. But because our aircraft does not have any articulating rotors or pitching propellers or tilting wings or other, I would say complicated or complex systems, we feel that this aircraft, due to its simplicity of dedicated lift and dedicated cruise systems, will have a much more clear pathway to test for safety and for verification validation. So last part of my talk, and we take a few minutes and talk about the challenges around energy storage testing to show that they're safe and appropriate for use on aircraft. I'll be focusing on cylindrical cells. We are in development with Kuberg on advanced cells for our application, but the examples I've taken today will focus on cylindrical cells. In general, there's three broad classes of testing that we have to do at the aircraft level. We first have to do safety testing of the battery systems. We're also very interested in cycle testing. And then finally, we do environmental testing. This is everything from salt fog to high altitude, humidity to all these other factors, EMI. And so if we start at the left, focus truly on the cell first, and then the module, and then the battery pack. A lot of effort is spent there. That's the most important step because if you have the highest energy in this cell, but it's very difficult to package safely, you can't successfully implement it. And so we do a lot of testing at that level to ensure that we can appropriately package the cells in a module and then a battery pack level. The next most important thing to us is the cycle testing. How long does the battery last? How does it behave? Any unusual aging functions because fuel gauging is very important to this industry. The accuracy of reporting the battery's capability such that one can reliably land the aircraft at low state of charge is very important. But the challenge, of course, is that the aircraft is often flown between, let's say, 100% state of charge and 50%. Not often does it go from 50% state of charge to lower. That's what we call the reserve range, or let's say. And so there has to be a very good mathematical model, probably based upon a good fundamental understanding of the electrochemical reactions. It's very difficult to do all of this cycle or fuel gauging with simple equivalent circuit models. One really needs to go down to electrochemical modeling. And finally, environmental tests. That's the sort of the refinement, finally at the end of polishing the stone. I will go over just a few of the tests that are difficult and I'll show you examples of how we do testing around one of those. The majority of the requirements given to us through the DO311 requirements, so many of them are easy. Make sure the battery has the rated capacity or make sure it has grab handles so you can lift it or move it. There are some of those requirements that are low risk but still need some discussion or how do we pass this test or what's the appropriate manner? I call those yellow or orange. And finally, there's the three high risk tests. Thermal runway containment, 50 foot drop. And one of the tests that can be very difficult is the over discharge and recharge several times without protections because that can induce failure inside the cells. And so I'll be spending a little bit of time on, for example, the drop testing. And everyone likes slow motion pictures, right? I brought, and I'll give you a movie here. But 50 foot drop test results in the aircraft hitting the ground. And in our particular aircraft, the batteries are located underneath the floor. It is for several different reasons. I know one of the questions online during the seminar that was given is why don't you put them in the wings or is the wings the best place for the heavy batteries? That's one possible location. But depending upon the design of the aircraft, the center gravity, center of lift and some other factors, we decide to put the batteries under the floorboards. And so we are prone then to the 50 foot drop test and the batteries are in close proximity to the impact zone. And so we developed tests where we were able to induce failure and simulate the crash test. Can you see that running? Just give it a few seconds. This is a 21700 cylindrical cell and it was pressed into a hard barrier and now it's ejecting from inside like a little booster rocket. And I think I stopped this video before it gets totally consumed. But it's very typical of these cells. They do not take damage in the axial direction very well. All right, let's move on. This is now, the next slide is a cylindrical cell, same, but now in the radial direction. And we done a lot of testing really to see how the cells behave. These have happened to be from a major manufacturer but this is not the sort of data that is given to you from the manufacturer. So often you have to derive it yourself. But we will be working with Kuberge and an integrated effort to come up with modules for aviation industry based on their pouch cells. So that'll be a collaborative effort. All right, we found that the radial direction these cells were much more robust. And what that led us to do is orient the cells in the aircraft such that the axial direction would never point downward or forward because those are the two directions which an aircraft has to get crash tested in. And so if I move to the next slide, we then developed modules with the proper cell orientation and then subjected the modules for example to the impact tests. And I'll just let this run. It's a lot of fun for our engineers at work to develop the test fixtures. So you can see the response for example of this module. There is a small amount of electrical arcing initially due to the fact that the module does break some electrical connections at roughly the 50 volt potential. One cell is shown leaving this package. This still has to go through a lot of refinement and we're changing the design but it just shows you what sort of testing takes place after the cell is manufactured and brought to the integrator. I hope that gave you a good overview of electric vertical takeoff and landing aircraft, some of the challenges, and also a practical example of the testing that's necessary in order to show that the batteries are safe for use in an aircraft. All right, Herman, thank you so much for that presentation and connecting us to the cell and the module level. Very exciting videos that gives another meaning to shooting batteries. So we are running a little bit late so maybe I will just put one question forward. So you talked about fast charging and you also talk about the fact that the state of charge for the battery tends to be on the high side compared to EVs. So can you speak to a little bit about the different application requirement for fast charging for electric planes compared to EVs? Certainly, I can go back to the first customer that engaged us, United Therapeutics, which is a delivery of valuable medical cargo or assets or organs to, for example, hospitals and or transplant centers. When that aircraft lands at the transplant center, it is unloaded of its cargo, but it's also very important to then move that asset, that aircraft, because it has to make room for the next emergency helicopter 911 call, whatever, to land at that helodeck. So there are requirements sometimes for fast recharge or at least partial recharge or at least just what we call a two hop mission where you achieve your first destination, deliver your cargo, but then you have to exit that and move on. So there are applications and situations where either the aircraft has to move to a place where it can take a little longer to recharge or it has to do a fast recharge at that location. But it's not the majority. We're seeing many people can actually park their aircraft for at least an hour or two. And so fast recharge is not a universal demand, but there are applications that need it or at least your ability to do a partial recharge so that you can move the aircraft to a storage location. So to follow up on that Herman, so from my sort of impression of how the planes will be operated, sometimes if you need the fast turnaround, then the charging would follow discharging pretty quickly. And this is maybe a little bit different than some EV applications where charging are happening overnight, for example. So does the thermal management become easier? What plane will harder in the sense of charging? It's more difficult in an aircraft to deal with the rapid discharge or rapid recharge of the battery because as Richard commented, some of the C rates are up to about four or five C rate during landing. It turns out you can actually get a thermal hit or accumulation of temperature during the V tall landing component. And then you turn around and try to recharge it quickly. And that actually is the longest, most challenging from a thermal standpoint because the battery's temperature could be raised by several degrees, right? So thermal management is very important. The difficult part is that thermal management on an aircraft is expensive because you have to carry the coolant, the pumps and everything else. And so we're doing a lot of work developing thermal management from the ground based equipment such that you fast recharge the aircraft but you're also thermally recharging it or resetting it. And those two have to go hand in hand such that the aircraft is then prepared both thermally and electrochemically to then take off and have another mission. Very interesting. Thank you very much. Herman, thank you very much. I'll come back for more discussion at the panel session. So if I can invite Omer to come to the stage. Absolutely. Thank you, Omer. So it's a great pleasure to also welcome Omer as our third and final speaker today. Omer is the founder and CEO of EVation. And he is a physicist by training and is also an entrepreneur by practice. So very exciting to see the combination of the two come together here. And he has been leading EVation for six years to bring electric flight to reality. And I just also wanna add he has a substantial experience from the government and defense side and therefore also bring that picture into consideration here as to spend a number of years with the Israeli Defense Forces after finishing up at the rank of a major and also work in the office of the Prime Minister of Israel for a number of years. He's also a great contributor to the community at large participating in the mobility working group with NASA. So Omer, without further ado, the floor is yours. Looking forward to your talk. Thank you, William. And really thanks Richard and Herman for the great presentations. I promise I'll be brief. So we'll have plenty of time, but let's just dive right in. This is Alice. This is all EVation aircraft does as was mentioned. I've been running this company since inception and it's actually seven years tomorrow. So you were right on the six years, but guess what? And yeah, been there for a while. I think the main difference or the thing I kind of want you guys to keep in mind is that we build a very big battery. It happens to be stored in an airplane, but technically it's a battery. And one of the reasons I like the picture that you can see in front of you is you can see that parting line. It's now painted, but when this was taken it was before we hit the sealant line. You can see the parting line between or let's say under the windows. The entire subsection of this aircraft and it's a 16,500 pound aircraft is battery. We have an 8,300 pound battery. So just over 50% of the maximum takeoff weight of this machine. We're based in the state of Washington. So Mount Rainier in the background and terrible weather usually, but hey, someone got a good picture. And the story of the company is fairly simple. We started back in early 2015 and built a lot of iterations. We've built different planes. This is internally, we say that this is iteration 164, 164, but obviously what's really interesting is what was built and shown. So in the 2019 Paris Air Show you can see the picture in the middle. We had a very, very different aircraft. It was a tail dragger and had propellers at the wing tip but before that we had even funnier configurations. And eventually we zoomed into something that looks a little more traditional can be certified a bit more easily. And the one I would say silver lining for all of those iterations was what I said at the beginning. It always had a huge battery anywhere between 45 and almost 60% of maximum takeoff weight was battery. And the reason is the fundamental elephant in the room, which is batteries are actually a very, very poor way to carry energy around compared to anything else we do. And we're getting better not quickly but we are getting better. And what I wanna talk about today is a bit about the company, a bit about the product and then a bit more about the pack and the need and the issues. The aircraft is awesome. We take nine passengers and two crew and a total cargo capacity in our cargo variant of 2,600 pounds, 2,500 and the commuter variant. We fly 440 nautical miles plus 30 minutes VFR reserve and we do it with today's terrible 21700 roughly 260 watt hour per kilogram battery cells. So please Kuburg, fix that. The cruise speed of the aircraft is 250 knots. So it's a fast machine. And you can see some of the data here on the left regarding performance. But I think the interesting part here are actually the last two lines. We cruise quite efficiently compared to a beachcraft King Air which is roughly equivalent size and weight at the edge of its weight capability or compared to a Phenom 300 jet which is again roughly the same size and weight. We use far less energy. So Herman's comment regarding a lifted drag ratio is definitely the driving factor here as well. There is a reason for this funky egg shaped fuselage. It's not just because we think it's nice. It's because while energy density was kind of the connecting line for the last two presentations, energy volume does matter as well. And when we try to just take this huge battery we can't put it in the wing just because there isn't enough volume there. We have to put it in the fuselage and that actually creates a very, very stupid thing. You're trying to take a very slender silhouette of a wing, make it as light as possible and lift a very heavy egg in the middle. This is a design that would make airplanes clap, any airplane. And obviously you try to avoid it. The way to avoid it that we kind of contemplated was to create the lifting body to make the fuselage participate in the lift. And around 20% of the lift of this shape is created by the fuselage. It alleviates some of the loads on the structure but not less important. It also creates those cheeks on the side that gives us that extra volume needed. So that's where the battery goes. You'll see it in a few minutes. Our plane, this is actually a picture of the plane taxing. It's around the 75 or 80 knots. And that's another thing to remember. When building what's called a seat hold there are some huge benefits if you are a battery but the complexity and the testing needed just to get to the point that this is safe enough to fly is significant like any other program and it's extremely high energy. We moved that 16,500 pound aircraft that up to 110 knots on the ground and then take off with it. So that's a thing to look at speaking of all of those crash tests, belly landings and whatever you can think of any clever way to mistreat a battery. I really could relate to Herman's videos. I'll show you one of our own. How do you build a plane? Well, with partners. Aviation has been working with these industry leaders for years developing everything around the flight control computers with Honeywell, building the production, let's say tooling and systems for the wing with GKN the guys that they did the wing for the A350. We're using motors by a company called MagniX down here in Everett, Washington. We use a lot of systems by Parker and I think the centerpiece here in the middle that people usually do not recognize because they're not from that industry is AVL. AVL is our test organization. It's an Austrian multinational and they are the test organization for battery development. So that company has a lot of experience in building powertrains for both more traditional auto industry and for the battery world. And we've been leveraging some of their expertise to do our cell level, let's say modeling or at least the fact finding. And I think one of the reasons I said I wanna be on this panel is because of Kuburg. Now, one of the beautiful things about experiencing in this industry is that we've all been talking about that threshold that let's do 400 watt per kilogram be awesome. Well, I've been in this industry for quite a while and I've been working for the auto industry a bit before that. And I literally found the chart and unfortunately I can't share because it's proprietary for the guy that made it that showed that promise of the 400 watt per kilogram back in 2005 saying, you know, by 2010, NMC 811 is gonna get there. That's only wait for that, it'll be okay. And I found it again in 2012, by Nissan saying, you know, by 2020, we're gonna be there, don't worry about it. It's solid slash high silicon content. We don't know, but one of those and the joke in the company goes that there are three kinds of liars in the world. There is a liar, there is a big liar and then there is a battery supplier. And I have to say, Richard, that Kubrick is not like that because they actually claim what they can do. And we've been testing with those cells. I don't think there is a cell manufacturer on this good earth that hasn't got a visit and an order for a bunch of cells from us and we didn't go testing with but unfortunately cell companies do not die in the lab. They die scaling. And we've seen it throughout the industry development efforts with A123 and Via and LZN Labs and with many other attempts over the years that were less famous, but not less painful. And I think it is an extremely difficult problem not just to hit the numbers, but to hit price and to scale. And one of the beautiful things that's happening with the way Kubrick's taking it is actually that collaboration with Northvolt. Obviously still yet to be proven. And obviously I'm still designing my battery around the 21700 cells because I need 43,000 cells per plane and not everybody can deliver. So it's a challenge and it's a huge challenge to see mature to the point that we can actually say, yeah, we can use this cell, let's go for it. And that's really where we're at today. What you see here is obviously the number of fasteners holding the battery in place. As I said, it's a big one. This is what our battery looks like conceptually. This is where it sits in the aircraft. So we have three logical battery units that are identical from an electrical perspective but not very much from a mechanical perspective. The piece you saw under the fuselage is the left-hand side. You can see it's a mirror image between left-hand side and right-hand side. So it's under the belly if you will or under the cabin. That takes two thirds of the battery and we have an aft battery that takes up another third of the total energy. The system voltage is nominal 800 and it connects to three major systems. To the two motors, to our home-built, let's say environmental control system. So it's an integrated thermal management system that does both the cooling of motors and battery and the heating of batteries if needed and the heating of people and everything that needs to be done. That's also an 800 volt system. And it connects through an array of DC to DC converters to our 270 and 28 volt system to allow for the other, well, to the rest of the aircraft to operate. So our aircraft is the first all-electric commuter aircraft out there. It's also the heaviest. But it's also the first part 23, which is a category of certification of light aircraft. It's the first part 23 all fly-by-wire aircraft. And that means that we can't lose power ever. If we lose power, it doesn't even fall like a rock. It falls like a plane, which is worse. The idea is that we can always rely on one of those three battery packs. They're completely redundant. Each of them can fly the plane actually quite significantly and safely. So they survive, they work through a DC to DC set of converters, so some redundancy there and they feed into a smaller array of smaller batteries, 28 volt and 270 volt buffers that will give us an uninterruptible low power supply, no matter what, even if the high voltage somehow fails and you don't have propulsion, you will still have buffers that will allow control of the aircraft. So this is a very, very critical system, obviously, not just because it's fuel, because it feeds everything. Each of those areas is built into ribs. Those ribs are our module. I have to say I don't completely buy into the concept of one single module to fit all, mostly because I haven't seen it yet. I've seen a lot of attempts out there in the last seven years. Unfortunately, none actually worked for us. So we built our own. We have a very, very weirdly shaped module. It contains 21700 cells. As Herman mentioned, the right thing to do is not to put the cell in the direction of crashing. So we got to the same conclusion as you can see here, but obviously very, very different from other perspectives. We're using five amp power cells today because they're readily available and we have two battery packs. So again, we build big. So when we test something, it's the pack. We do have two battery packs with 5.2 amp power cells that are beginning to be available in the market right now, which is nice. It's an improvement. Total usable energy in this pack is 820 kilowatt hours. So you do the math. It's basically a pile of 10 Teslas. And it weighs accordingly, 3,700 kilograms or as I said before, roughly half of our max takeoff weight. From a sea rating perspective, we're actually the best customer you can imagine. We cruise at roughly 0.4 sea. We take off at roughly 0.9 to one sea. And even in an emergency condition, a rejected landing that requires a high power kind of back in the air situation, we are looking at roughly 1.5 C from a situation where we lost part of the battery. So from an amperage perspective, not as bad, the system is capable to go all the way up to 3,000 amps, which sizes a lot of components that we had to build ourselves just because they either do not exist or were built for rail and that's heavy. The battery itself has a lot of provisions for structure, for venting, for cooling. And I will kind of talk about DO311A for a second year again. The standard for how to certify a battery is more or less understood. The testing of it is a bit more challenging, but I think the connecting lines are very simple. You need to build a battery that will not propagate fire and will be able to exhaust the energy of a thermal runaway in the case where it happens to a certain number of cells. Now there are arguments between different territories. If you need to burn all the cells in a module, just two of them, five strategically picked, it doesn't really matter. There is a thermal runaway event, you need to prove you can survive. Those big vents modeled on the bottom of this battery package you can see are actually the way we get rid of energy. So huge vents, roughly the size of a basketball to get energy and fumes out when and if something like this happens and then to hold it at the single cassette level, meaning every one of those ribs can kind of withstand the heat and can get rid of the energy as needed. Sorry, but no pictures for this. There's way too much IP built into this one. The other side of this is how do you get energy density slightly better? And the answer is structural integration. So our battery packs are, as you can see built as ribs, they carry much of the pressurization load of the inner tube that actually holds the cabin, the people and they make sure that we can withstand the difference in pressurizing the cabin. They also hold some of the lateral loads on the skin. So kind of making other structural parts of the aircraft less heavy. So kind of cheating our way into a higher energy density capability. That means it is not as simple. And speaking of a lot of questions that usually come in, why not replace batteries? Let's talk about charging. Charging is less of a problem than people think. It's an infrastructure challenge. There is plenty to do, but it's doable. Today we charge an hour in the air for about half an hour on the ground and we can actually do better than that. We charge it anywhere between 500 and 700 kilowatt. The standards that are coming online soon will go all the way up to 900 kilowatt, but the 500 kilowatt mark is actually good enough for most of our missions and our clients. It's good enough for turnaround time. And if we go to 700, we even beat what they ask for. So that's usually not the issue. A plane that size and that weight will usually have many things to wait for. The time it takes to load it, to unload it, to clean it. The time it takes for breaks to cool. When you land a plane this size, you usually wait for about 10 to 20 minutes for the braking system to cool so you can safely brake again. So there are a lot of operational concerns that have a lot to do with the aircraft and that kind of timeframe and turnaround time allows you to plan for reasonable charging. Battery swapping, especially if that battery is structural will take a geometrical miracle and we believe is the wrong way to go. This is what the battery look like eventually. It's a big piece, you bring it in. Why on earth would we do this? So the reason to build an electric plane is very simple. There is a huge market out there today. I am one that thinks that while electric propulsion can and will revolutionize the way we travel, it will do it because of its economical viability, not just because of the fact it's sustainable. Sustainability is super important for our relationship with our planet and it's also super important for the way we look into the future. But at the end, what needs to drive this is economy and the market is there for a 500 mile tool to take you far and fast and that's a replacement market for existing planes of that size but it's also to take a chunk away from those 737s and A320s that are being used for short range. I actually think that when we look at the VTOL world, there is definitely great potential for revolution there but I like to look at these markets first within the regulatory environment and the operational environment of the business models that actually work. The VTOL is a helicopter that doesn't make as much noise and doesn't spoo as much and hopefully costs way less. The same goes for the ALIS. We get to decarbonize but we also get to reduce the direct operating cost by anywhere between 30 and 70% and that's because of the cost of energy and because of the cost of maintenance and the cost of maintenance really is the main driver for the understanding of what this industry will be able to pay for a kilowatt hour. It's not as sensitive as the auto industry but it is sensitive to an extent. On top of that, you get lower noise and it gets you to open up just new airports and new areas that were not reasonable for flight so far so that should grow the pie and yet I do wish to see thousands of planes like this flying around soon enough. So what do we need from our future battery cells? As I said, today we're using cells that start their life at roughly 270 watt hour per kilogram and go down to around 260, 255 when we finish our thousand cycles. We do not love it. It's a cylindrical cell, 21700 and it is readily available from the auto industry. We're piggy-bagging and that's what there is in this volume. Do we see a beginning of a change there? Yes, can we do pouches? Absolutely, we build those packs in different shapes and sizes. That's why we're working with Kubert like we do with many other battery companies. We would like to see anything over 300 watt hour per kilogram because it allows us to go further and carry more. Now we obviously would like to see more than 400, 500, 1,000 whatever someone can give us, we can wrap our heads about but the question really becomes do we have a range issue? And my answer is no we don't, not according to our clients. Flying 440 nautical is more than enough in a cabin this size. It doesn't cover 99% of aviation missions but it covers around 75% and that's huge. That's more than enough. So the question really becomes if I can make a battery that weighs a battery pack that is, that weighs 50% of what my battery pack weighs right now because we just did a 2x improvement in cell energy density. Would I take it and would it immediately translate to higher let's say payload, effective payload as we call it? And the answer is well, it's not that simple. Center of gravity in an aircraft is a tricky thing and we once designing an airframe are committing to something that is extremely difficult to change. So there is roughly a 10% margin we can play with meaning I can take a 10 or 20% drop in the weight of the battery and directly replace it with more cargo or more people but anything beyond that becomes a different aircraft. And I think we need to remember that when we build airframes, we build them for 25, 30, 35 years. That's actually the average age of planes out there today. So what we did to accommodate this was to create what's called a TSO meaning the battery has its own certification effort and it's a unit that you can in a maintenance procedure replace. So one day hopefully with Kuburg or with other players when new and different batteries incrementally improve what we have today, we can definitely create a new battery but we will aim to actually pack a fairly similar weight and just give the plane more range that would be more likely the scenario we're gonna see. From a thermal runaway perspective, I wish we could have a cell that doesn't burn ever but I do not believe this will be the case in the foreseeable future. So mostly we need to see predictability and that goes to quality assurance and that goes to manufacturing process and that kind of goes to my next point as well, consistent manufacturing quality. The advantage of those huge manufacturers is that they make many, many millions of cells a week. So cell number one and cell number 43,626 is very similar and if you can control this, your ability to model, predict and build safe systems increases exponentially. If you have surprises all the time, it's extremely difficult to build a safe system and you need to take huge margins and those create something that's less usable. So the balance needs to be struck not just around performance but around the ability to manufacture a coherent set and then to actually model it correctly. Reliable future availability is also a huge thing. When we built our plane that you saw a picture of just a minute ago, we built it throughout 2020 and 2021. We're gonna fly it in 2022, three, four and five because it's a prototype. A client of mine will probably take his delivery of a plane in 2024 and will like to fly it also in 2044. Will I be able to get cells even if I don't want to change anything all the way out a decade from now? The answer needs to be yes or very close to it. So there are issues here about how can we predict what's going on next? And then reasonable price, we're talking about roughly $200 per kilowatt hour at the cell level, mostly because we believe we can pay two or three times what the auto industry is paying more than that kind of breaks the mold for other reasons. But again, that's probably not the discussion here. So what's the problem? Because it seems like, okay, so Cooper's working on it. Northwell's gonna manufacture it. Don't worry about it. We're done. I'll show you what we're playing with most times. This is actually a thermal runaway event that went wrong. This is actually only eight cells. I don't think that sound is very important here, but the picture is very clear. This is by the way, a liquid cooled and the liquid cooling system just couldn't take it. This gets way worse, so wait. So when batteries burn, they burn hot. This burn was recorded. It's not Kubrick cells, I have to say. You guys do way better, but this is a high silicon content cell that burned at roughly 1,015 degrees C. So extremely hot and extremely hard to contain with anything. And we're testing a lot to make sure that we don't get this. We get all sorts of uneventful puffs and try to keep it that way. And it's all about cooling quickly and aggressively and venting, venting, venting. So there is plenty to do in terms of the design and safety is obviously paramount. It is, we're building a commuter aircraft. The aviation industry today is the safest mode of transport ever developed by mankind. And if we don't keep to that standard, we're out of the business. So that's the challenge. Manufacturing, as I said before, that's not just on the cell size, but also on the pack size side. Sorry, it's extremely challenging. It needs to be done in a very, very controlled manner. Cost is obviously a big deal. At the end of the game, the driving force for this market and for the adoption of these new tools will be there making economic sense. And if we break that mold too far, I just can't do anything. We'll have to wait till it drops or just piggyback on the auto industry that's actually doing a very good job in kind of racing to the bottom on the cell size and cell price. In terms of real energy density, one of the biggest considerations we look at today is not just what can the cell do, but what will this cell need in order for it not to burn? Like these cells burned, so how far do the gaps need to be? How big the cooling system needs to be? How hard do you need to apply pressure on these pouches, for example, to get the electrical characteristics and the repeatability of performance that is needed? That will create a true apples to apples comparison between a pouch cell of any size to, let's say, an array of cylindricals. And that combination of factors is really what drives our decision-making going forward. As I said, we have built four pouches at the range of around 12 amp-hours. And we have obviously built for a cylindrical. So we have some experience with both, but I do accept, Richard, your comment completely, that building anything over 25 or 30 amp-hours becomes to be very challenging. It's very hard to get rid of the energy in a thermal runaway event of a single cell or two cells. And you really create this huge amount of heat and pressure to evacuate. So we never built for anything bigger than that, but we do believe that we can handle anything up to 15 amps quite easily within the realm of what we're doing in a day-to-day basis. But again, size matters and an 800 or let's say age, kind of edging towards a megawatt hour of battery in terms of nominal capacity is challenging from both the manufacturing perspective, thermal management perspective, and obviously just sheer testing. I don't have a slide here about the charging, but I do wanna add a small comment about that. Today, one of our understandings is that while we do leverage auto industry standards for charging, we just use two CCS cables to get what we need. In the long run, we're probably gonna look at either kind of future standards of auto adopting more rigorous standards so that they would fit the aviation industry better. And I think I'm beginning to see the same thing in the auto industry in general. So if the aviation industry does not suffer a thermal runway as an event you can live with, both in kind of the operation of the aircraft, but also around charging and its challenges, the auto industry usually looks at the thermal runway as a question of how bad is it? Meaning there is a question of what's called the graceful burn or the graceful thermal runway which means if I can give you five or 10 minutes to get out of the car and then the car burned, it's not so bad. Obviously it doesn't quite work for airplanes. And I think what we're beginning to see is a high level of interest by the auto industry into the practices and experience gathered by companies like our own in creating the non-propagation solutions out there. And I think what we're gonna see from a systems perspective is a bit more of a convergence because it's gonna be important enough to both the auto industry and the aviation industry to make sure that these packs are bulletproof, pun intended, because the defense industry also cares a lot and there's plenty of learning to be done there as well. So I think there's plenty of multi-industry learning to be had and that's all I had to say. We'll be happy to take questions. Oh, Mayor, thank you very much for the talk. And I think we are running a little bit late in time. So let me just suggest we go to the panel discussion and incorporate some of the questions from our audience there. And I just wanna say one thing is here at Stanford, we really talk about this from atoms to systems integration. We talk about it, we work on some of it, but it's really exciting to see how the three of you are embracing this really just across the materials level, the cell level and module level. And thank you for speaking to that today, learned a lot. So maybe I will kick off with a question inspired by Richard's backup to envelope estimation. So Richard, you highlighted that the cost requirement is much less strict than for electric vehicles. And this relaxes a lot of constraints and Herman and Omar, you also alluded to that in your talk. And in my mind, I see sort of two things that you can do differently because of that relaxation. One is you can embrace expensive technology. And number two, you can also embrace very low yield technology. And this makes me think of semiconductors, right? So as you introduce new semiconductor processing, the yield is always very low, but you can make something. And so I wanted to ask the three of you to sort of comment on what technology you see in both camps, something that is very expensive and impratical in terms of cost for EVs or other applications, and something that has very low yield, but when it works, it can deliver what you need. Maybe I can ask Richard to start. Sure, so in my mind, you know, what example would be actually on the module design where for instance, heavy use of carbon fiber is something that we anticipate happening in aviation modules. And it's something that I'm not really sure would be viable for a mass market passenger vehicle, but it has large benefits in terms of propagation containment as well as as light weighting. So that would be one example off the top of my head. I have to, if I can jump in, I have to not only agree, it's, we build our composite. So our modules are even more exotic than carbon fiber. It's a combination of Kevlar ceramic. There are plenty of insane materials that, you know, once out there make for a way better combination of both thermal management and load bearing. And that's usually the combination that we're looking for. Totally agree, same answer. In an aircraft, you would sell your mother to save 10 kilograms. So if something, technology that is very weight savings or promotes safety, as Omar mentioned, some of these Kevlar's or ballistic materials are very useful as ceramics. So if they're low yield technologies, that's okay, because we're willing to pay the premium for safety in weight savings. And in some cases they're reusable, meaning the, yeah, the batteries go away, the cells, but the pack can be recycled. So even from a yield perspective, sometimes you can actually kind of build the ecosystem in a way that's not that bad. Omar and German, on the engineering, the mechanical engineering side, are you already seeing some benefit in the non-battery structural weight of the aircraft by using the battery as a structural component? Are you saving elsewhere outside of the battery? Battery is a structural component. Maybe Omar, you could speak to that because you had it more integrated, right? Yeah, so for us, absolutely. We dropped, so the weight of the fuselage will be dropped, well, not will be dropped, but on this fuselage that you saw in the pictures is actually a 5% lower, almost 5% 4. something. Then what it would have been if we had to build it without the battery and then add the battery. So there is, and it's mostly about just replacing ribs. So if you come to think about it, if you look at kind of a conceptual design of any aircraft, we have this double bubble concept, right? You have a bubble on the inside and a bubble on the outside, and there are ribs along the way. So I showed you a picture of roughly 24, not roughly exactly, 24 ribs. Probably from a mechanical perspective, an optimized number would be closer to six or seven ribs for a piece that long. So 24 is not optimal, but still it's better than zero and it's better than having a battery and then having your six optimal ribs holding it. So we saved around 5% of the weight of the fuselage there. And we did not. We have batteries, for example, that are mechanically separate from the fuselage and we didn't want to take credit for that. And we thought it'd be easier path to certification to verify, validate the design and so it'd have separate batteries, separate fuselage. And we wanted, just for future growth, we thought we could just change the batteries in the future to different or upgraded. So we took a different path. We're paying the 5% fuselage, things like that. So it's an evolving, emerging industry. So the answers aren't always obvious or known the correct answers to the best answers. And so there'll be a lot of different approaches to design and manufacture. Absolutely. And one of the challenges, I really appreciate, I love the design that Beta puts forward mostly because of its simplicity. And I think one of the interesting considerations we didn't kind of, that weren't as trivial is that at the end, we all need to crash test. And when you do say, okay, this is all integrated, it means that in every test you're gonna sacrifice probably another fuselage. And that's very painful. On the other hand, it does create all sorts of unique opportunities. For example, we did have a kill beam that we figured will be just for belly landing protection when we designed the first fuselage before integrating. And then we created the kill, if you could have seen it in the pictures, I guess. So the two internal walls of the battery packs are actually those huge aluminum ribs. We barely have aluminum on the plane. And the reason is that that's actually the new kill beam. So it kind of opens up new design opportunities. But yes, there is a significant price to pay and obviously anything you do adds complexity. So that's always a consideration. Well, both of you, Ashel, all three of you alluded to battery safety. And E is Mr. Battery Safety here at Stanford, leading many programs in exciting progress. E, would you like to ask the next question, perhaps along the lines of safety? Yeah, I'm thinking about safety for sure. I mean, the three of your talks, all these all get emphasized, right? Safety certainly has the going from the inside the battery cell internally all the way to the whole system. You can put in safety enhancement ideas right there. Giving the end the air mobility requires such high safety compared to anything else. I really want you to ask you anything, maybe stuff on WeChat, right? Inside the cell. I mean, it's a matter of certainly, I mean the safety instance, what 40 years ago still very clear in people's mind. And what can you do to enhance that? And then certainly for Oma and Herman, right? Then when you pack yourself together, what are the strategies? What new things would you like to see if you can share with the audience? Yeah, Rich, I'll maybe start from you. Yeah, so it's something we think about a lot. And I think there's kind of two different ways to look at it. One is really from internal materials and cell level, how do you make it as reliable as possible and redundant in terms of failure modes? And then the other one is really the mechanical design of the module that itself needs to be certified. And that's less about sort of probability of runaway and more about like just the nature of the runaway, how the heat gets released. So I think for the cell, some things we look at, for example, are one of these concepts is with these like aluminized plastic current collector that has a shutdown feature. And it can defeat internal short circuits hypothetically. And this kind of thing, I'm not sure like it will do anything from like a certification perspective, but really from a practical safety perspective, I think it'll be quite profound in terms of really avoiding internal short circuit as the key mode of cell failure. I think the other piece of this is really developing much more robust data systems. And again, FAA is kind of behind on software. They don't like a very advanced software being a safety system. If they don't understand how it works, this is my understanding, but really from like a maintenance and operations perspective, being able to understand degradation modes in a much, much better fashion using electrochemical data you get from your pack, I think has huge value. And then once you move to the module side, that's really where we talk about, containing the size of the cells, reducing the amount of heat that comes out when your cell does go into thermal runaway, slowing down the rate of the heat release as well. I think are some variables we look at. Yeah, Richard, maybe let me just resin them back to the materials inside the cell level. Something we saw is adding the fire retardant type of chemicals in there. Of course, into electrolyte, it will be limited right there. A couple of years ago, so we started to use, you mentioned aluminized plastics as current collector. We actually started to put the fire retardant into the plastics for the current collector. Once there's something going on, certain temperature, 150 degrees C, you can release that and hence the safety. So that has not been done testing in a very big cell, but I can appreciate the idea. Fundamentally, in the materials and chemistry level, if you can make it safe, you automatically made the whole system very safe. Yeah, maybe to Herman and Oma, if you wanna make comment on the module and the system level. Yeah, I would love to. We could throw out a wish list, please do all these things. But I think the fundamental objective is to make the cell failure its expression as least violent as possible, because then it's so much easier to manage the subsequent cascading events. So to slow down the energy release, the exotherms, the release of electrolyte, the vaporization, the burning of it, trying to just make it slower, because we have challenges when it's really fast, really violent, it's really hard to contain, it's hard to manage from a pressure, a thermodynamic point of view. So paying attention to what goes into every cell, can we add separators? Can we add intimescence? Can we add all these little mechanisms that help to shut off the cell during failure? I think that's great, but it's also the highest risk place because that's where all your chemistry is happening. So it's a great challenge, a wonderful challenge, so worthy of attention. I couldn't agree more. I think if we can make it just burn not as hot, it would make such a huge difference. If we can make it burn, not for two seconds, but for three, it would make a huge difference. But kind of to kind of just reiterate the last point that you made, Herman, I think we need to let cells be cells and do your best, get the energy density, get the manufacturing right, get availability right, get the price right. We'll pack it. We've been packing terrible cells for a while. Well, thanks, Oma, just to mention to you, I remember seven years ago when Steve Chu and I brainstormed about how to make a cell safe, right? The idea is if you can detect that problem cell, can you release the energy of that cell out? So exactly try to realize what you said, not burn so hot, maybe at a system level, you can engineer something in, right? Detect the problem of the cell and release the energy somewhere, dissipate it, yeah. Exactly, please no thousand degrees C. It's not a target. I would like to add one subtlety here. It's always nice to make safer cells, but the aviation is so sensitive to safety, they will always push us to a point of multiple cell failure because it could happen, because they are not gonna believe you. If they say, oh, our cells are benign, don't worry. No, no, make them fail, push them to a cascade and then show us that you can contain it. And so that's really the modus operandi of battery engineering and the aviation industry. We will push the cells to failure. It may take triggering 10 of them simultaneously, but we must show that cascade and then show that the battery can contain it and or exit the flame safely out of a port external to the aircraft. I think there were some questions in the chat that address that as well. I actually want to briefly highlight one of Stanford's very interesting work led by my colleague, Simone Onari. So she's been developing a failure early warning system in the battery management system. So the ability to look forward and then see if probabilistically something is coming along the way. So this seems to have, could have profound impact for aviation because then you can do something about it. For cars is a little bit less so because, you know, take it to the shop, but here I think the stakes are much higher. Omar and Herman and Rich, I want to build on East Point again about the cell level safety features, but I actually want to go one level deeper to the materials level safety feature and the cathode and anode in the electrolyte. The way I see it fundamentally, you have two problems, right? The electrolyte is flammable and the cathode is the source of oxygen. So here's kind of a naive question for me. In terms of a good balance between energy density, power density and safety, it's lithium cobalt oxide, right? This is also why the consumer electronics industry has really honed in on that, a cobalt rich composition. If cost is not an issue, has that received attention at the cell level for testing in the aviation industry? I haven't seen it. We've considered LCO. We have not used it because at least my impression of LCO is it has quite good volumetric energy density but it can't compete on specific energy with nickel rich NMC. The other issue also is that the voltage tends to be higher to get to, they charge to higher voltages for consumer electronics which makes it more difficult for electrolyte design as well when you're trying to design a high energy system. So I haven't seen much momentum on the LCO side, to be honest. I think something worth to think about because ultimately these very, you know, these big fires is caused by, it's triggered by the oxygen released from the cathode. So initially you have a small fire, that's the electrolyte burning by itself and decomposing and then you have this amazing fire and that's because oxygen decides to come out. And Richard, as you know, for the nickel rich cathode, this is a real challenge. It comes out about 200 degrees C but for something much safer, say lithium-ion phosphate is 600 degrees C and cobalt is somewhere in between. That's what I thought it could be an interesting way to consider the availability of oxygen during a thermal runaway. Yeah, I think it takes the hits in energy but it's all about trade offs as all three of you commented today. So I think it's maybe something that is worthwhile thinking though. So how do you stop the oxygen from coming into the combustion process? So one, if I may comment and my apologies for a change of scenery but we're always on the move, right? I think one of the things we experimented with quite extensively and I think we will, well, we're not using right now but we probably will use in the future is just replacing oxygen with nitrogen in the area of burn. So we had an interesting set of experiments with high pressure nitrogen additions to the pack that burst locally where you have a thermal runaway event. And we found that in several different chemistries we found that the results were very encouraging in just in kind of lowering the peaks in just creating a more subtle burn. It doesn't prevent the burn itself but it does help prevent propagation. So I think that's definitely an issue but much like was said here before thus far we haven't been able to find a cell that did not rely on NMC and even specifically NMC 811 and worse I would say to get anywhere near the energy density we need. The other kind of materials point we've observed is that thermal runaway is still enormously poorly understood both academically and industrially. And there's a lot of non-obvious interplays that you don't see until you're actually driving big cells in a runaway. Like non flambo electrolytes I would say have both benefits and issues in terms of safety. It's actually a trade-off. It's not an obvious just simple win. And then the reason is typically they're more thermally stable so you can push your onset temperature higher which is good, absolutely good. But because these are thermally more stable solvents and salts they have much stronger chemical bonds. And then when that electrolyte eventually does combust and those chemical bonds break you actually release a lot more energy quickly because of those stable bonds. So you have this very sort of non-intuitive trade-off and like what balance of chemical stability and flammability or vapor pressure is actually ideal for optimizing that runaway release it's quite a complex trade. Well put Richard. Maybe I can maybe for the last few minutes take, ask the PAC experts here. You know, one thing that's sort of catching attention in the EV industry is using multiple chemistries in one PAC to deliver the power, the energy, low temperature performance and so forth. Has this been examined for aviation? Multiple energy storage technologies within a battery PAC or within a energy storage system. Let me just say multiple chemistry. Now multiple. Some people call that dual energy storage technology where there's a dual component usually a high power element and then a high energy element. For example, EV tall aircraft a lot of the initial concepts said, oh yeah we're gonna have a dual one for takeoff and one for cruise. And once you get done with all the analysis and all the additional packaging and all the additional power conversion and inefficiency of processing, et cetera. It doesn't pay off here better off with a large battery of one technology because it's large it's much easier to then achieve the power density goals. So it's only in those applications that truly have a bifurcation between the high power short duration events and low power long duration events that that really gets far apart. Then those topologies or applications can use a dual energy or a dual technology source. But for these applications it looks like we're just gonna go with that one high power and high energy cell. It's a nice combination actually it's very attractive. The technology that Keyberg's developing is it answers the both ends of the spectrum. I do have to depart but I've been so enjoyed my participation in this. So I appreciate Stanford hosting us and having a chance to share our challenging application with so many creative minds because there are a lot of challenges that still need to be solved. Well, I took a lot of notes. I'm sure our audience did as well and Herman, Richard and Elmer, thank you very much for taking time out of your busy day to speak with us. Let me ask Kaylee for the final slides. We have several exciting talks coming up. We have two more talks scheduled. We're gonna hear from Jessica Tresik to talk about energy storage at the systems level. And also Nicola Kemenel from McKinsey who will also discuss the Chinese market at a systems level for lithium-ion batteries. And then following that, we're gonna have two very exciting talks from our battery management and battery informatics experts, Simone Onori and Dirk Orseria from AHA University. And that's a good connection to today's talk as well on next generation battery management. So with that, thank you everyone for tuning in to our first session for 2022. And we hope to see you in two weeks. Thank you. Thank you. Thank you everybody.