 A very good morning from Stanford University. My name is Will Chu. I'm the faculty co-director of StorageX Initiative here at Stanford. And I'm delighted to be joined by Professor Itzwe, the director of the Precourt Institute for Energy, to host today's StorageX seminar. So we have a very interesting topic today related to battery technology. So batteries really span all the way from atoms to systems. And today, we are really delighted to talk about that larger length scale of battery technology. If we think about how to innovate batteries, we can innovate them at the chemistry level. But we can also innovate them at the cell level. And finally, we can also innovate them at the pack level. And today, we are really delighted to have two pioneers in this area to talk about innovating batteries from the cell to the pack level. We have Professor Chaoyang Wang from Penn State University, who has been doing extremely exciting work on thinking about new ways to improve battery charging capabilities at the cell to pack level. And we also have Mujib Ijas from our next energy from Michigan, which is also pioneering the design of battery pack that can tremendously increase the energy density at the pack level and also the range for electric vehicle applications. So this is a little bit of a different flavor than some of our more chemistry-oriented seminar. But I think we will find very exciting connections on how improvements in the chemistry can then be combined with innovations at the pack level to ultimately deliver a pack of unprecedented performance. And we're just really delighted to have both pioneers joining us today. To get us started, let me invite Yi to introduce our first speaker, Yi, please. Yeah, oh, thank you, Will. It's my great honor to introduce a friend, Chaoyang Wang. Chaoyang is a professor at Penn State University at the Mechanical Engineering and Chemical and Material Science Engineering. Well, Chaoyang is really an inventor. He holds over 140 patents, publishing more than 220 articles, research articles. He's known for his innovative work and batteries and also field sales. So if you look at his inventions, he's just going from a really broad range of topics, all very, very exciting. For his achievement, he is a fellow of a National Academy of Inventors. He's also a fellow of American Society of Mechanical Engineers. He received many awards, including Research Excellence Award from Field Sales Division of International Association of Hydrogen Energy. Certainly, I mean, no further ado in Chaoyang or let you tell us about your recent exciting research. All right. So can you all hear me and see my slides? Yes. Great. Hello, everyone. Thank you very much for having me and I'd like also thank Yi and Will for organizing this wonderful symposium and for inviting me. So the topic I'm going to discuss today is battery fast charging. So here's a short outline of my talk and I will explain my motivation, which has to do with enabling battery or EV affordability and sustainability. I will briefly discuss charging infrastructure and then present the challenge a bit more precisely as well as the underlying scientific issue of lithium plating. Then I will present a brand new figure of merit for fast charging and basically used to gauge the effectiveness of fast charging as well as to review the current state of art and follow by our approach, which is based on asymmetric temperature modulation and this ATM strategy really utilize a rapid self-heating cell structure in which we can conveniently control SCLA growth as well as tame lithium plating. So at the end, I will present an example of the state of art fast charging and conclude with some broad messages. All right, so my research into fast charging really is motivated by this realization that storing electricity in battery cost, let's say $125 per kilowatt hour, whereas refilling of electricity costs only about 12 cents or so. So we see a 1,000 times price gap between storing or storage and refilling, okay? And that means storage is awfully expensive and one doesn't want to store any extra electrical then absolutely necessary, right? And this may sound very ironic as we are all storage researchers and practitioners and we are in this wonderful storage symposium but the plain truth will tell you that any affordable EV simply means is small to medium battery pack but capable of 10 minute refill of energy or 10 minute fast charging. So this concept can be better illustrated by this schematic as where we basically replace 150 kilowatt hour battery pack by a much smaller one, 50 kilowatt pack, 10 minutes rechargeable. So in the right case, basically you have the 50 kilowatt used up and then wait for 10 minutes, you get another 50 kilowatt and so on and so forth. So that way you still get to use the whole 150 kilowatt hour energy without much inconvenience. But on the other hand, you pay only one third of the cost and you consume a third of raw materials and produce a third of carbon emission from manufacturing these small little batteries, right? And so in a sense fast charging is a very nice enabler of battery affordability and therefore EV affordability, as well as sustainability. So I look into sustainability, it's all about three hours, reduce reuse and recycle as you can see from, let me bring up a laser maybe. As you can see from this symbol, three symbols all together, wherever you read the textbook or search the internet. But in battery space, we hear reuse and recycle all the time, somehow we drop reduce, okay? But the truth of the matter is first and foremost reduce the most effective way to achieve sustainability and fast charging is a great tool to downsize batteries and therefore reduce raw material consumption and carbon emission from manufacturing batteries. And this is a particularly significant at the current times when we face metal shortage crisis and when the industrial CEOs cry for not enough batteries, right? So the idea really is to share a 150 kilowatt battery pack originally designed for one EV now with three EVs of 50 kilowatt each. So this reduced alone would be able to support 300% organic growth in the number of EVs without consuming additional raw materials or producing additional emissions, okay? So that is a power of fast charging. Now here comes a big question for us as scientists and engineers working in this area. And that is if 50 kilowatt hour battery pack is a new norm, okay? For at least mass market, electric vehicles, then what issues and priorities shall we focus on? Still maximizing energy density as in the vast majority of today's literature and presentations all start to look for something new and more exciting, right? So that's a big question. Also, if 50 kilowatt hour batteries are a new norm, then can we still ignore the lithium ion phosphate chemistry? Because at this size, we all know every batteries can fit very nicely in any passenger cars, both in terms of weight and volume, right? And it's 50 kilowatt hour LVP powered vehicles we probably can get 200 miles. And after 200 miles, if we make those LV batteries 10 minute fast rechargeable, then basically after 200 miles or three hours driving, the driver will go to the restroom and check on social medium. And when you come back, the vehicle is ready in 10 minutes for another 200 miles. So essentially you don't have range of anxiety anymore. And combining with other attributes like very low cost and high safety, abundant materials or LVP, you basically have an idea solution, right? For sustainable and affordable EVs. So I think we need to seriously consider the LVP chemistry in the framework of sustainable batteries. Now, what about fast charging infrastructure? So I look into it, I find it's not only available, existing, but also over capacity. So let me take Tesla supercharged network as example. Each of them has 250 kilowatt, can power 5C charging at 50 kilowatt hour, which means they can each can serve five vehicles per hour. And right now it's probably only doing one vehicle per hour, only 20% utilization. So it's largely existing infrastructure is largely underutilized. And similarly for 350 to 360 kilowatt DC fast chargers, they're popping up all over the place and they can power a 7C charging of 50 kilowatt hour. In other words, serve seven EVs per hour. And that's also largely internalized. So if we just use fully the existing fast charging infrastructure, that's already 500 to 700% grows in the number of EVs without even increasing any infrastructure. Now, beyond that, of course we can double or triple the Tesla supercharger network. And I'm sure that the private companies and government around the world will be able to do that. Okay, so the real challenge really boils down to finding and deploying 10 minutes fast charging batteries and not only 10 minutes fast charging but also be able to do so at all temperatures. Okay, so here I show you a map of average window temperature in the United States. And you see basically 25 state below zero and 47 states below 10 degrees Celsius. And whereas the fast charging capability is strongly sensitive, very sensitive to ambient temperatures. So I take a snapshot of Nissan Leaf user manual here. And as you can see for a normal fast charging at room temperature, cozy temperature takes 30 minutes. It will take 90 minutes if it's sub zero temperature. So we need to find a technology that can do fast charging in Alaska throughout the year as well as in Phoenix, right? And the scientific issue underlying fast charging is this phenomenon called lithium plating. So when I apply a very large current, you have a huge flux of lithium ions generated from cathode and they have to return into the anode and so much ion don't have time to be nicely integrated into graphite host. So instead they would deposit as lithium metal on the surface of graphite particle and that is irreversible causing capacity decay as well as is a safety hazards. So lithium plating are mostly prone to occur under high charge rate, obviously, and low temperatures. And as well as very thick electrode or high area capacity, which leads to high energy density or low cost. So we want all this problem to be solved, okay? Now, understand the blade fast charging is a pretty messy words. In other words, in terms of the literature, you have many claims and you have patent literature and academic literature because fast charging is desired for decades or for centuries ever since batteries were invented, right? And time is money. So fast charging is always desired. So with all this much literature, so we decide to put out a new figure of merit to gauge the effectiveness of fast charging. We also use it to evaluate the current status of the literature so we can position ourselves better for the future development. Now this figure of merit consists of three metric parameters, charge time on the horizontal axis, obviously, right? And then the vertical axis is energy acquired by such fast charging in watt hour per kg, okay? And one can also use area capacity acquired by fast charging in a milliamp hour per kg. It's the same thing. And that is important because you need sufficient energy for automotive driving. And then the third parameter is basically is a number of fast charges cycles. And that is a measure of life and represented by the size of the bubble on that plot. So here I show you two, a pair of figures. And on the left, you basically have the data points or the technologies with cycle number exceeding 800, so-called automotive target. And then on the right, you have more or less emerging chemistry and system that has cycle numbers still short of automotive target. In each other figure, I also have a few shaded areas. And the upper left corner here is what we define as automotive acceptable box for fast charging, basically defined by less than 15 minute charge time and more than 200 watt hour per kg acquired energy. And within this box, there is an ideal target located here with this sizable bubble. So meaning it has to be long lasting, even after fast charging. And then we have a few other shaded areas. And here is a lower corner here, the LTO chemistry battery using LTO material, which basically is so-called no string material. So particularly suitable for fast charging. And then, but the energy density is a little low and not very useful for automotive driving. But then if you replace the Anna with graphite, you start to get this range of energy density with a lower limit more defined by AFP castle and high limited by high nickel NMC cathode. And then if you further replace with silicon anode, then you get another bump in energy density. And if you do lithium metal anode, you get further increase in energy density all the way into 400 watt hour per kg area. Okay. And then in addition, you see three groups of data here and this very gigantic orange bubble basically is LTO battery. As expected, very doable and you can cycle many times. You can charge in less than five minutes, but again, unfortunately the energy density is a little low. And then you have a here bunch of graphite based lithium ion batteries and making steady progress and start to enter this automotive box for the very first time. So I will explain a little bit more details shortly about this group of research. And then up here, you, this blue symbol as blue dot is basically for lithium metal solid state batteries and you can see there's significant amount of energy acquired after charging but the charge still takes several hours. Now in the emerging chemistry or system area, basically by large, you see all those bubble tiny teeny and those are need, you know, basically meaning there's not enough sufficient life and you will need to improvement. And in particular, you see those, there's a few pink points here and they all have a little bit too small bubbles and meaning that the cycle life is too short and that is consistent with the biggest issue facing silicon anode battery. Basically they are lacking the sufficient calendar life and therefore I think dealing ways, stability and durability of silicon battery is still the biggest challenge before we consider fast charging. And for the lithium metal batteries, you also see a few data points spreading around and probably the closest to this automotive box is this work by Liang at all and they acquire 300 watt-hour per kg energy. It takes one hour one seat charging, okay? So that's a current state of up. What about our future? And as we know, RPE currently has ongoing FOA and which basically calling for two targets in two categories and both target can be very nicely sprayed in this figure of merit. The first one is demanding five minute charging acquiring 160 watt-hour per kg and the second one is 15 minute charge and calling for 320 watt-hour per kg. So now with all these data points, you see this is our current state of art where we can realize today and then there's two near-term targets. Those three data points really form the battlefront to tackle this ideal target and they are getting very close. So I'm very confident that this ideal target of automotive fast charging will be realized in near-term. Now, how do we do fast charging? It's different from the literature other people's work. It's a physics method based on the so-called asymmetric temperature modulation and it can be illustrated here. So we basically leave the battery alone during operation. Let's say rest or discharge or, you know, as usual at ambient temperature, but whenever you bring an empty battery to a fast charger, we will give a quick preheating to an elevated temperature like 60 degrees Celsius. And then at that elevated temperature, we enjoy enhanced kinetics and transport and therefore eliminate lithium plating and then do the 10-minute fast charge. You finish it up and once it's done, then the battery will naturally cool down and you go back to, you know, your normal business of operating the battery. So the key here really is to control the time for the battery to expose to elevated temperature. But fortunately, this is a 10-minute fast charging. So very short. And technologically, a key element is really to find a structure or a way to rapidly heat up the cell and it has to be, you know, down with the heating speed greater than one degree per second or be able to heat up from room temperature to 60 degrees Celsius in less than a minute, right? Because charging time is only 10 minutes. So we have to keep it quick. And conventionally, heating is done externally and either by circulating warm fluid or by putting external heater and those are all very slow process and typically at a speed of 0.5 degree per minute and going from room temperature to 60 degrees Celsius will take already about an hour, okay? So, and this is why Tesla has this so-called own route battery warm-up strategy. In the other words, if a driver needs to go get a fast charge, you have to tell the vehicle ahead of time hopefully 45 to 60 minutes ahead of time, push the button and then by the time you arrive there, the battery is warm enough to do a super charge. Now in our research, we use a self-heating structure which we first published in 2016. So it's actually a very simple construction. You take a pouch cell, which is typically 10 millimeter thick and then you insert a nickel foil which is only 10 micron thickness and as showing here as a yellow sheet here. And this, you know, there's two ends of the nickel foil. One is welded into a negative terminal and other is sticking out to form a third terminal we call the activation terminal. And then you place a switch between positive and activation terminal and you take this such a battery to a charger and connect it as usual, so positive negative. Now, before you do the charging, you basically turn on the switch and therefore the charge current will all flow through the nickel foil to preheat the cell from whatever ambient temperature to 60, let's say. And after the charge temperature is reached, you turn off the switch and then the same charge current starts to charge the battery material. So it's only one key action and you will be able to accomplish this process very quickly. Here, I use a schematic to show the advantages of ATM method and, you know, essentially we want to eliminate lithium plating while limiting ACLA growth. So you plot the reactivity of power level of battery versus the time throughout the lifetime. So obviously during, you know, normal driving time the battery is designed to output the sufficient power for driving at ambient temperature. So nothing is changed. But once you come to the high power fast charger you will receive a, yourselves will receive a quick thermal stimulation in less than one minute. And then at this elevated temperature which will give you superior power level suitable for fast charging without listen plating and you finish the 10 minute fast charging after that and you go back to the normal driving and the cells will quickly cool down to ambient towards ambient temperature, okay? So in this case, yes, we do have the accelerated degradation during elevated temperature period, but as long as we control time we can limit this growth. So at the end, you know, at this ATM mode the battery capacity retention is a function of ACLA growth at a 60 degree Celsius and then the degree of lithium plating whether we can reduce it or eliminate as well as some little other miscellaneous factors we all remain the same as in other normal conditions, okay? Now, how do we limit ACLA growth at elevated temperature? We did a lot of characterizations for a large number of materials, okay? The figure on the left is for NMCA11 graphite cells. We put them in constant 60 degree Celsius over and cycle all of them so that we know we know the ACLA in use degradation at elevated temperature. And those are for very thick electrode, 4.2 million power per square centimeter loading, one C, one C cycling or medium 3.4 loading but with the same active material, same BET area and therefore they are ACLA characteristically remain the same. Also we deal with different electrolytes and as you can see also they collapse on one single curve between the capacitor retention and the time, okay? And as a matter of fact, following nearly square root of time as we would expect, okay? So at this point, you can see that it's all about time. Similarly, our early data using NMCA523 graphite cell doing the same thing that blue symbols basically constant over testing at 60 degree Celsius and the red ones are ATM operation which do the 60 charging at 60 degree Celsius and one C discharge at much lower temperature but still at the very beginning and you basically see those two data coincide with each other and it's all about time. So time will decide the capacitor retention. Now how much time do we actually stay at 60 degree C in our operation? Let's say we do 1,000 fast charge cycles and each cycle here 10 minutes, 1,000 the total time is 167 hours throughout the lifetime and that time at elevated temperature is only a tiny fraction of battery lifetime. And if I prod that ATM time staying at 60 degree Celsius over this, you know, this two part you can see the resulting capacity retention is still far above where about the 80% limit, right? Now this is a 1,000 all fast charging all staying at 60 degree Celsius. If we follow USABC criteria which only require 25% fast charging cycles and then this will be reducing by factor of four the total time reduced by factor of four and we'll be talking about something like 40 hours in here. So capacity retention is not an issue. Now what about our ability to eliminate lithium plating? As we know it's all controlled by three processes. Iron transport through this very thick negative electrolyte in the negative electrode in the electrolyte and then you have a charge transfer reaction at the graphite surface and followed by the surge step which is a lithium atom diffusion in graphite particles. And all those three process can be greatly enhanced by higher temperature. So as showing data here about the simple message is that if we go from 20 to 60 degree Celsius in other words, thermal stimulation we will acquire a novel electrolyte as if novel electrolyte with doubling conductivity and we will create a novel graphite material with six times improved diffusivity within and we also develop an engineered interface with 12 times improved the charge transfer kinetics. So one single action of thermal stimulation creates three as if new materials and that is a power of ATM. Okay, so with all these powerful principles and mechanisms and then we can carry out the fast charging in numerous systems involving many different materials. So here I give you one example which involves 270 watt hour per kg NMC811 graphite cell and we can put it at a 4C fast charging to 75% SOC and acquire energy at the beginning of life is a little over 200 watt hour per kg and you can see that we can easily cycle 900 times, right? Now if we take the same cell do the 4C charge only to 70% SOC then the acquire energy is a little bit lower, not 190 but then you can cycle much longer beyond 1700, okay? So those both set of data now put it together in comparison with the DOE target showing here as a dash line, okay? So it's a practical method. And if you look at the detailed cell voltage and temperature curves, it's very interesting. First of all, you see a one period pre-eating takes about less than one minute and in which basically cell voltage remain the same there's virtually no electrochemical activity it's just a charged current passing through the nickel foil pre-eater cell from ambient to 65 degree Celsius rapidly, okay? Then after that switches off and your charged current is charging the battery voltage goes up and you charge it to 70% or 75% and then after short rest and followed by CO3 discharge and nicely output the energy, okay? Now if you look at the temperature curves and first you see amazing result you see during 4C high current charging the cell temperature would remain nearly at 65 degree Celsius despite the fact that the cell, the test cell is sitting in a second room air. So in other words, there's no liquid cooling and there's no even fan blowing air towards the cell. So it's all under natural convection and you can still be able to dissipate a very large amount of internal heat generation and the reason being very simple it's basically the temperature different driving heat generation is huge. The cell is at 65, ambient is 25, okay? So you enjoy a very large temperature, that RT basically. And then after you fast charge you are followed by CO3 discharge. This is mimicking a situation where we leave a fast charging station and then we start to drive over the highway at a speed limit. In other words, consume the entire cruise range within three hours, right? And that's really the speed limit. Even if you do so, you see the cell temperature would drop very quickly to below 40 degree Celsius in about eight minutes in this case. It's all natural convection, nothing, right? And below which basically we know the cell is very safe. Now we can significantly use this cooling time eight minutes to maybe a couple of minutes if we activate the so-called aspirated air convection. So in other words, open the valve and then the with a driving on highway you basically get air sucking to cool the battery pack automatically. So the message really is it can be summarized as, right now we can do around 10 minute fast charging and acquire 200 watt hour package to be able to cycle more than 1000 and under the passive cooling condition, okay? So it's all those basically metrics all together. Now I just want to touch up on very briefly about safety consequence of fast charging. In other words, relationship between fast charging and safety, right? And this can be illustrated by, again, by this sketch plotting the reactivity power level versus temperature, cell temperature. Now if you prefer a quantitative way you can also use the inverse of DC resistance or internal resistance of the battery, okay? And for state of the art battery basically showing as a green curve here and as we all know, those batteries are designed to provide enough power level for driving around room temperature, 25 degrees Celsius. And then as the temperature goes up the reactivity increase, power level increase and then there's a safe limit and beyond which you start to see the own set of thermal roundaway. So we are not supposed to exceed this safety limit. Now if you do fast charging the reactivity of power level has to be higher than driving but lower than safety limit. So somewhere around here. So obviously in order to design or develop a fast charging batteries using whatever new materials we invent we have to increase this reactivity level or inversely decrease the DCR in manifold, okay? And that can be, oops. So that can be illustrated by this new curve. So you have to shift it out upwards either by higher reactivity or by lower DCR tremendously, okay? And then this is also necessary, better understood if we know that the normal battery can be charged in one C if you apply four C then we got to reduce the DCR by factor of four before the charge voltage will jump right away reach the upper limit and shut down everything, right? So it's necessary. And by doing so the consequence we have to consider after all this method is the premature own set of thermal roundaway. Now the ATM method a trade this fast charging versus safety relation differently, we don't change the materials or chemistry. And so this curve remains the same. And what we do is before you when you bring the battery to a fast charging and we will give a rapid preheating from whatever ambient temperature to a elevated temperature or a charged temperature. And so that you have sufficient reactivity which will support the fast charging once you finish it and the battery naturally cool down and you go back to the do the normal business. And so you still remain in this curve and the thermal roundaway own set of thermal roundway remain the same so without compromising the safety. Now let me quickly just put up some broad messages. I think for us as researchers a battery electric chemistry R and D should include how to include how to maximize energy storage but also how to maximize the rate of charge turnover because this is a very low cost method to get things done. So for industrial community of course there's a multiple opportunity to monetize this archer low cost fast charging while I still enjoy double way in sustainability. So if you're downsized you will be able to reduce raw materials carbon emissions as well as increase utilization and charging infrastructure. And for those fast charge batteries to be deployed in the marketplace we should have no less safety. Safety cannot be compromised and preferably do not demand more cooling that will cost money, right? So the whole message is less is more. I think we can get things done with a small to medium battery pack. And that small to medium battery cap battery pack can already achieve cost parity with gasoline cars especially the AFP chemistry. And so with that I want to thank acknowledges the support funding support for my research from DOE also Argonne National Lab who conducted the third party independent evaluation of our technology defender endowment at Penn State Air Force SPR-12 and then a large number of people at Penn State EC Power teams and who helped me to learn and basically understand this asymmetric temperature modulation method for fast charge. I will stop here. Thank you very much. Well, Chaoyang, thank you very much for the very interesting talk. Very cool idea here or say hot idea. So why don't we, let's ask a few questions right here for the time consideration probably we will not ask for too long. Chaoyang, the first question is about implementation of this idea. Let's see, it requires three terminal of the battery cell. Maybe cylinder cell will be harder to implement. This is more like, you know, plasmatic pouch cell type of configuration. Do you foresee the challenge in the battery manufacturing or this is all set? Yeah, this will be a good opportunity. I think audience probably wants to know, yeah. Yeah, this is a great question. I think obviously this is, you know, edit procedure to the existing fabrication production line. But I think that fortunately it works well with the trend of cell fabrication. As we know, you know, all the cells are going towards the so-called bigness, right? We see the blade cell. We basically see all the cell made, are made bigger and bigger and with much more space for a third terminal. And, you know, and single cells are made much bigger. So 150 amp hour, even 200 amp hour. So this is a pretty ample space for to install a small terminal. That's one. And second, it's actually this configuration has been a pilot produced for the Winter Olympics just, you know, in the past February. So it was, you know, the whole pack was installing about 200 or 500 vehicles. I forgot, electric buses and commuting in the Winter Olympic competing sites in Beijing in the past February. So I think it's, you know, it requires some work, but I think it's a small engineering kind of thing. Yeah, congratulations, Chaoyang. That's very impressive to see this is implemented in Beijing Winter Olympics. Second question from the audience. Certainly the cooldown time will show about a minute. This depends on the size of the cell, probably mostly the thickness of the cell. Any comment on the size of the cells if I go on the cooling time? Yeah, that's another good, great question. So we tend to think the cooling time is depending on the sickness, but the modern way of cooling or thermal management is not through much sickness. In other words, it's not through the electrical separate the sun brain because the thermal conductivity along that direction we call through plane direction is very low. In comparison, the in-plane direction along the foils or the electrodes, let's say take a cylindrical cell as an example from top to bottom, that is almost 10 times higher. And that is just nothing to do with the sickness of the cell, whether you make a thicker cylindrical cell or a tiny 18650, they remain the same. So we actually rely on, I think what you mean is because this current collector metallic foil probably conducts the heat to the edge a lot faster than across the perpendicular to the separator and so on, yeah. Exactly, try to all the conductors through many, many layers of separators. Yeah, okay, that's great. So, Chow Yang, another question, I keep wondering, you use 60 degrees C, certainly it's a temperature give you a fast kinetics, that's the main mechanism, but 60 degrees C is also more than a usual, I mean, this usual can change. This threshold may be 55, why not using type of 55 below maybe 50 to play say, then you don't lose that capacity that much. I understand 10 degrees Celsius, kinetics change quite a bit. So what about 50 degrees Celsius instead of 60? Yeah, that's also a very good question. Obviously, the charge temperature is variable. I mean, you can do 45, 55 and even 70, 80 and so on, depending on materials and systems. And if you talk about solid state, I probably can go up to 80 and 90 degrees Celsius. So it's a scalable and it can be even reconfigured, onboard, it's very easy to do, right? Now I mentioned 60, I just tried to challenge the conventional kind of mentality. I think it's time for us to change that kind of mentality for two reasons, number one. And I think we all agree that battery safety is very, very important. And therefore a battery have to be heat resistant. So if we researchers and developers and manufacturers are still very much afraid of 60 degrees Celsius, there's probably no hope to have a safe batteries in the future, right? So we have to overcome that kind of our own kind of limitation. And that's one thing. And second thing is, I can tell you, I only stay at 60 degrees Celsius for about 160 hours. And most recently, you know, Professor Jeff Don actually stayed in 70 degrees Celsius, constant 70 degrees Celsius over for over six months. And he still emerge out of that, you know, stay safely and with very little aging. So I think this is evolving, understanding and I think more and more so for the future, we got to be able to embrace more heat resistant batteries. And I think 60 really is probably not a big issue. Yeah, yeah. So I've asked one last question and then invite we will chair to moderate the next talk. So, Taoyang, these heating going really fast, one minute and also involving cooling later that eight minutes, maybe for bigger size, a little bit longer. So during this process, is there any concern of temperature in homogeneity? Or from particularly when you heat it up and then you do charging, right? I mean, globally, it looks stable temperature. It's just local temperature variation to be a potential concern or maybe the low, because you have the foil right there and try to think you have the foil right there. You do the dual heating, the power, is there anything spatially can cause a temperature variation slightly? That might induce the plating issue because of temperature variation in the same cell, yeah. Good point. That can be managed. For example, I mentioned we have one foil in a pouch cell 10 millimeters thick. And if you have 30 millimeter thick prismatic cell, even in thicker cells, we put two or three foils and we can even put the foils between two jelly rolls because those big fat battery cells are made of many jelly rolls also. So you can insert, you basically can distribute. You can think about a slice one nickel four into a few slices, insert in different locations and then you have very uniform temperature distribution during heating. Now cooling, we rely on, like I said, it's very highly conductive current collector foils. And that's not a problem because after, I mean cooling is basically also volumetrically. Thank you so much, Chaoyang. Why don't we move on to the next talk and if you can stay with us. So after Mojit's talk, we can come back to have a small panel discussion. Thank you. Thank you. Well, back to you. Thank you, Yi and Chaoyang. Thank you for this very disruptive presentation. I really enjoyed it. And from one disruptive idea to another one, let me now also invite Majib to come to the stage. Thank you so much, Majib. It is my great pleasure to introduce a true veteran in the battery and electric vehicle industry. So Majib has a long standing career in the auto industry and in the battery industry, starting 30 years ago at Ford developing electrify vehicles both involving batteries and fuel cells. And he then moved on eventually to lead a CTO of A123 systems to develop innovative battery technologies there from the cell level and up. And then, and after that, he decided to come out here to the West Coast and join Apple to work on some very special ideas. And that brought us to the pandemic and many of us are struggling during the pandemic but Majib decided to and start a company and I think it was June of 2020 just at the onset of the pandemic, truly inspirational what you have accomplished over the past two years. And today, I think Majib will share with us technical details of the technologies that he has been developing with his team at our next energy. And I just wanna say that it's rare to have a person with this diverse experience in the battery and EV industry really looking at all the way from materials to sell to pack. And I think that really resonates with our belief as storage X where we have to have a systematic approach and looking at the systems level, how to connect everything. So, Majib, we're really great. It's really our great pleasure to host you here. The floor is yours. Thank you so much for the introduction and it's great to be with the panel here at Storage X. I actually might kind of reflect on the many interactions that I've had being in California and meeting Professor William and his team and his startup was also an inspiration. I know that there's a lot going on in the battery and energy storage world these days that's evolving the mindset around development of chemistry as well as supply chain and then architecture. And so I'm happy to be here and share with you what we're thinking about at our next energy. And so let me share my screen and I'll get my presentation up here as well. So as William introduced the background just briefly, my career over 30 years sort of ebbed and flowed between battery technologies that were very advanced like the first one that I worked on and Ford was sodium sulfur to then due to safety and some three fires that happened in the early 90s retreated very quickly to the safest and most conservative approaches like lead acid and nickel metal hydride. And this early part of my career got kind of interrupted as I was really well convinced in electric vehicle that we could create an electrified platform that would satisfy the market. Fuel cells were brought in in the late 90s to try to overcome a range problem. And there was at least 10 years spent working on developing solutions that could get to zero emissions with range. And I start my talk with that story because in some ways we're still working to advance technologies that satisfy the full market. And one of our vision points at our next energy is that we think we need to be able to double the range of where we are with today's electric vehicles to get to the mass market that's out there. And that's not a well-established or well-accepted premise because needing to double the range of electric vehicles from where we are today sounds like we need 6, 700 miles of rated capability. And many OEMs would argue with me that that's number one way too much cost to put on board a vehicle. Number two, why would you carry around so much range if the average customer's expectations for range today are in the three to 400 mile range levels? And so I'm gonna talk a lot about that but really founding the company on the premise of needing to double the range of electric vehicles also came with a discussion at our early stage of what are the chemistries that we want to put our effort behind? And while we didn't select an exact chemistry that we would put our effort behind, we did select that we would not put effort around Cobalt. We think Cobalt is a long-term supply chain problem and Cobalt exists in nickel Cobalt chemistries because it is a stabilizing force but in electric vehicle terms, the level of market adoption and the level of need in the global community of electrified platforms, the Cobalt supply chain constraints are not going to be able to keep up with demand to such a degree that we believe the Cobalt market will become a barrier for electric vehicles but in addition to that, the nickel Cobalt manganese family of chemistries that are being pursued and I'll add NCA to that as well have a risk of thermal runaway and self-oxidation. And so we decided, let's just make a premise that we're gonna avoid nickel Cobalt for supply chain and security reasons. And our third goal was to develop a sustainable supply chain that could be mapped globally to the local markets that we go into specifically North America does not have a robust supply chain and so we decided to go after developing solutions to the problem. So if I now go back to the 30 years that I've been watching the industry and participating in the industry of electrification, this map is a range of vehicles and battery technologies that have evolved since the very early 90s. And if you look at the lead acid dots at the very bottom left, Ranger EV for Ford and EV1 for GM were two examples of vehicles that were working through development of an early market that might be constrained by range but at least there was some attempt to get over a hundred miles of range. But as I look at the real evolution, it's the last decade and maybe less than a decade that have adopted the nickel cobalt family of chemistries almost to an exclusive degree, every major successful electric vehicle today is using nickel cobalt in some form and vehicles like the Nissan Leaf and others, the GM Spark that used LFP or LMO, those vehicles are no longer considered to be competitive because the adoption rates for vehicles that use nickel cobalt getting above 300 miles range have shown the market acceptance is much better. And if you look at the left chart, the EPA rated range is a very big discussion point when consumers are thinking about which electric car to buy. And as we study that, and especially in the early phases of the company back in 2020 when it was founded, we wanted to actually develop a target like if we're gonna go after a battery system, what should that target be to get to the mass market? And so we pulled a study and it was a 14,500 person survey and the question was effective, one of the questions was effectively at what range level do you consider an electric vehicle your only vehicle? Then that's quite different than the early market where people will adopt an electric car because they want the electric car and they're gonna be willing to deal with compromise. And for example, Nissan Leaf had a pretty significant market and it was very successful in the early market, but it was a niche market. It was an early loyal following of electrification that generated that market, not necessarily the mass market where people have constrained their buying decisions around certain requirements range being one of them. And so in that survey, what it suggested is that between four and a 50 and 600 miles of range, the market no longer cares what the range number is. It's basically now moved on to other factors in the buying decision like price and product mix and capabilities and platform choice and even brand. But the range number needs to be that high to get to the full market. 75 to let's say nearly 100% of the market needs range numbers above four and a 50 miles for that one or two times per year excursion. But if you go deeper the situation, and by the way, it looks like in this case of mass market, we're not that far away from the mass market, but we actually have modeled that we're actually further away than most OEMs are admitting or letting on. And the reason for that is the real world range numbers are significantly lower than the EPA rating, especially when you get into the most common feature of having range is taking a long distance trip. Now, if you go Metro Highway, if you go into just city mode, vehicles that are driving around, you know, San Francisco Bay Area or LA or any of these other metro areas are oftentimes constrained to stop and go driving and low speeds and at that level, electric vehicle efficiency and prediction of EPA range are well aligned. You capture regen braking, you're not going very fast, so aerodynamic drag isn't a problem. But when you get onto the highway and your speed limits have grown from 55, two decades ago to now even 85 or 80 miles per hour in some states, you go to Texas, you can do 85 miles per hour in the legal speed limit. That market of truck and Texas and being able to do 85 miles per hour on a trip, it needs to be considered when advertising what your range numbers are. And I would actually say that my one third off from EPA to real world is a very generous estimation. Actually, I think it's 50%. You can lose 50% of EPA rated range by driving at highway speeds like 85 miles per hour with some climate control, heating or cooling included. And if you add terrain like living in Colorado or even a small terrain state like Kentucky, that's going to dramatically affect your ability to achieve your goals. And so what we decided to do is plot the percentage of market willing to adopt against real world range. And we decided at 33% reduction on EPA would be a good starting point. And four to 500 miles, getting just above that 70 to now 95% of the market, we think that going after an energy density goal or the ability to achieve our 450 watt hour per liter, 300 watt hours per kilogram would become the system level target that our next energy would go after. So with that goal in mind, we set that goal I think in August of 2020, shortly after we were founded, we decided to then take a look at benchmarking and understanding where are the best battery packs in the world with respect to achieving that goal. And if we look at the NCM and NCA batteries of the world, the best batteries out there were around 230 watt hours per liter, 44% of the battery pack, the exterior volume was cells to sell the pack of 44%. Typical battery pack sizing of 80 kilowatt hours, 330 liters and about 2000 cycles of capability. That describes a lot of batteries that are in using pouch cells and metal can prismatic. The cylindrical cells that are being used by Tesla, the battery packs were also around 235 watt hours per liter, but it had only a 32% cell to pack, the packing ratio of cell to pack got worse, but the energy density inside the cell got better. But nevertheless, the net result is what the OEMs care about is the system level 230. And so remember my target of 450, that means that we're actually aiming to double the amount of energy in the same space to satisfy the market. Now, if you look at the NCA-NCM chemistry platform, if you have a failure and a cell goes into thermal runaway, that will quickly lead to a cascading effect of that consuming modules. And I would say that the prevention of thermal runaway, once you've included four or five or 10 kilowatt hours of energy going rapidly into thermal runaway, it is not possible to stop that at a pack level without very significant controls. And in tearing down at least a dozen battery packs, I don't see significant controls being used in the pack level to prevent that from becoming a pack fire and eventually a vehicle fire. And we see that, we see that there are recalls that are happening, there are NHTSDA investigations, there are shutdowns of various programs that have used large format cells because of thermal runaway and nickel cobalt related chemistries. And so what our company decided to do is charter a course without nickel cobalt where we actually employ lithium iron phosphate or LFP and in making LFP a root chemistry and deciding that that was a sustainable chemistry, it was good for mining, good for CO2 emissions, good for product safety and good for cost. We decided that we would turn the equation around a good systems engineering approach just to ask a question that, okay, if I want that chemistry what is the necessary attribute that I need to achieve at a system level to enable that chemistry to exceed the market in today's nickel cobalt terms. And so setting a target for a new battery that we called ARIES was one of our objectives. The second was setting a target for a second battery concept, Gemini which I mentioned at 450 watt hours per liter. And we decided in that battery, we called it Gemini because it's a twin is it uses one battery for daily driving using LFP and then it uses a second chemistry for range extension like an onboard power supply through a DC to DC converter. And that gave us the ability to start enabling very sustainable and non self-oxidizing cathodes that would then help with safety costs and still not give up on the range goals. Now, in order for ARIES to exist we would have to go after a very high cell to pack to make lithium iron phosphate viable. We calculated out that we'd have to be at 76% cell to pack in order to enable a 287 watt hour per liter performance at a system level with LFP chemistry. And if I show you the breakdown, what you can see on the left is a Volkswagen and this is by the way a pretty common architecture pouch cells go into modules, modules go into pack. That architecture results in a typical NCM cell at around 530 watt hours per liter losing much of its energy density through cell to pack at only 43%. But also gravimetrically at 66%. So the net result is a 236 watt hour per liter system level performance of energy density and 169 in gravimetric terms. What we've done, we would leveraging LFP and a high cell to pack is retain a much higher fraction of the initial cell chemistry capability at 379 watt hours per liter, which is a very good chemistry achievement for LFP in the days that I ran product development at A123. I think it was around 220 watt hours per liter and the cell was maybe a little more optimized for power because the battery packs were very small. Today's LFP, which are being optimized exclusively for energy in that level of energy density, 379 is a really good number and if we can maintain 76% of that flowing to the bottom line, then we can enable a higher performing LFP pack using cell to pack as an architectural shift. Now, as we look at our Aries pack in physical terms, what that meant is we had to go through quite a lot of pain on enclosure design and compression design and welding and making sure that we have bonded welded and permanently integrated product, also separating out the battery management system so that it could individually and separately be serviced in that front unit. And so the architecture of the battery had a lot of pain to go through to enable that, but the net result is we have a very successful energy density now using lithium iron phosphate. Now, if we look at the landscape, we have the second dot on the graph, which is the Gemini or the second battery product. And really thinking about Gemini is that now that we have a cell to pack model or a mindset, we can use a dual battery architecture to start enabling a much higher range number than was previously enabled with other approaches. And so let's now study the chart on the right first, which is customer behavior, and then we'll go to the chart on the left. So if you look at the chart on the right, the average daily driven distance for an electric vehicle in the United States market is just less than 50 miles, it's that dotted line. And that is the average where, if you go to a metro highway model and people working in cities, and you don't want to be in your car all day, so it makes sense that your commute is in the neighborhood of half an hour each way, that gives you a way to think about the early adopters mindset, but really getting to 99% of daily use is the better way where you really get to the full market approach, where 150 miles a day would satisfy 99% of the use case of the market. And in that context, it's why early electric vehicles are able to get a market, but the real decision to buy an electric vehicle, this is the emotional factor, and it goes into the studies that we've read, is that people think about that once a year, twice a year, the uncertainty of charging, or the hassle of stopping the charge too often, and they just want the range number to be so far out there that it doesn't get in the way of the convenience of being able to just get where you're going. And by the way, anyone that will try to argue back that, well, it's not that big of a deal to stop and charge, think about brands like Uber, Instacart, Amazon that are making their fortunes out of convenience for customer mindset. Everyone's trying to find a way to resolve their lifestyle without obstacles and fast charging while it's effective sometimes, is really a band-aid to the ultimate solution of just give me enough range to get where I'm going so I don't need to interrupt my effort to get there. So that purchase decision being wrapped up into the big range number, we started realizing at the early part of the company's founding, that we could divide a battery into two specific chemistry objectives. The left one, the blue one, is going to be very durable, very significant in terms of depth of discharge capability, power capability and delivering a daily use case. And then the right hand, the yellow battery only needs to be used maybe four times a year thinking about the 1%ile. And we went ahead and tripled that and said, let's use it 12 times a year. But even at 12 times a year, you only need a couple hundred cycles of capability for that range extender. And so now we go to the left chart. And the left chart is scientifically always been true. Whether it's when I started my career in 1990 at Ford and coming out of Virginia Tech in a solar car or go back to Thomas Edison's earliest batteries in the late 1800s, early 1900s for electric vehicle, there's always been this topic where a new chemistry emerges on the left, meaning cycle life's not proven and its energy density is high. And then it's hard to migrate from the emergence of a new chemistry that's very like elevated performance is exciting to automotive requirements where you're gonna need lots of cycles, lots of durability, lots of power, lots of temperature, robustness. You have a lot of requirements around automotive that are tough. And that's why automotive doesn't have but a library of four or five chemistries that are really used every day. And maybe it's even three chemistries that are widely used. It's because maturing a chemistry to automotive can take at least a decade. And that's the quest I'm on right now is our next energy thinks that we can accelerate the adoption of new chemistries by decoupling the daily driver and making that lithium-iron phosphate. And that blue section is 150 miles in the battery pack. And then we can make a choice of the most significant and best chemistries that are emerging for very high energy density. And those would be, for example, 200 cycles would be enough for a good durable 10 year automotive requirement. And that gives us a lot of flexibility. And in this case, we selected anode-free manganese as a cathode material. We're developing our own chemistry for a range extender cell. But I'm gonna show you now a chart where I think it's, this is a bit of me just speculating and predicting the future based on the past. If you look at the nature of these cloud diagrams where, oh, I'm sorry, I didn't label my axes. That's a terrible thing. On the bottom is gravimetric are watt hours per kilogram chemistry for a cell or cell level energy density. And on the y-axis is the volumetric density in watt hours per liter. If you look at that very common way of viewing chemistry clouds and where chemistries perform, we are currently in the phase of development in the 2010s to the 2020s where intercalation and single electron per ion are the chemistries that we are all working with right now. And one has a R&D effort, gen one and gen two that are basically working on intercalation model and anode-free is the higher end version of that. But there's also another generation of chemistries coming and I see that emergence happening right now which is that you get multiple electrons that will emerge with a much higher energy density but they're going to have a much lower voltage at end of discharge. And so the second thing that we're seeing as an architectural topic is that if you fast forward 10 years we're gonna be in a position where advances from maybe great institutions like Stanford and others in the world will come up with an energy density that we all want but it's gonna be complicated to use. Conversion chemistries are notoriously slow in C-rate. They have very difficult times with operating conditions and maybe temperature. They also have very difficult times with wide voltage and that bottom right chart of voltage curves kind of shows that a conversion chemistry the blue multi-step chemistry line you can start out at 400 volts at a battery level a pack level and end up at 150 volts at the bottom of discharge most motors and inverters don't like that. So our idea is to decouple the range extender behind DC to DC converters that then can use energy at whatever voltage and C-rate that is necessary. And then you can slowly transfer that to the traction battery, the blue battery and that battery being smaller 150 miles a day is there and ready to be charged by its power supply on board and it runs the motor inverter directly. And in that architecture while we're working on anode free we're also quite agnostic. We actually are working in collaboration with several companies that are on the right hand chart here developing various energy density options at low cycle life. And so we have a supplier C and a supplier B working on more than 800 watt hours per liter 400 watt hours per kilogram kind of chemistry is where the cycle life is not good enough to make it into automotive but we can actually develop the candidate for a range extender application while we're working with a common LFP traction battery as we go forward. So if I now plot what does that look like at a system level? Whether you pick a sedan, an SUV or a pickup truck the battery pack sizes a little different. You get sizes like a Tesla Model 3 has a 330 watt hour per liter pack or sorry, 330 liter pack. The condition of a pickup truck could even have a 500 to 600 liter pack volume. And why that's important is that remember we're trying to deliver power daily driving and daily range with the blue battery. The percentage of volume allocated to the traction battery takes away from how much range extender I can put on board. And so in that map you have this sort of design envelope where Gem and I can depending on whether I want 150 miles a day or a hundred miles per day that's the boundary of the two curves there that design space is an OEM decision. So as we've received now OEM interactions that we're working with car companies to design Gem and I for their platforms some are smaller, some are bigger. The solutions vary. But if you look at the left we're in the 400 to 500 watt hours per liter capability with cells that are on test today and batteries that are going in sedans, SUVs and trucks. And that is about double where the market is right now. And if you look at how quickly can you scale up for example an anode-free cell we are building 170 amp hour anode-free cells right now. After only a year's worth of development we've been able to resolve electrolyte cell compression and gassing and lots of topics. And 200 cycles is the reason that we're successfully moving so fast is that we don't need the cycle life to be full automotive and we don't need the C rates to be full C rates. So comparing ourselves as a benchmark between Aries and Gem and I to three commonly referred to battery packs in the industry we have the BMW i3 as an NCM pack using 622 chemistry. We have a Tesla Model 3 using NCAA cylindrical cells. We have the LFP version of the Model 3 which is a very good advancement I believe and shows strength in our assumption that LFP is going to pick up massive traction and displace NCM and NCA at a baseline level. We see these three batteries in volumetric density at 151, 232 and 173 watt hours per liter both of the batteries that we're producing and prototyping at one have energy densities that are higher than that. 287, 474 we're actually moving forward with the agenda of trying to double the range of an electric vehicle but also get rid of nickel cobalt as a heavily relied upon material. So with that I will turn the talk back over to our moderator and appreciate you taking the time to join and listen and I'm happy to take questions as the moderator as William would direct. All right, Muji, thank you so much for that. Quite in depth overview of your technology always appreciate startups sharing this level of detail. So we have a number of questions. So let me get started there. So one question Muji is on the use case of your range extender concept. So with these more advanced energy dense systems the catalog life at high state of charge is also an issue as well. So the question is the way the range extender is operated is it, it will be charged before use and then most of the time it would just be in the low state of charge states to maintain life during storage. Yeah, we think that the state of charge ideal for the range extenders around 75% it won't be kept at a low state of charge but it is unlikely that we want to keep it at the highest state of charge. And where you could think about that is let's say that we set a target where the vehicle has a range capability of 700 miles EPA and we take 25% out of that range extender that might take 100 or 150 miles away from the range extender. Still a very, very solid amount of range is always available. And that you could have the ability to boost charge when you're really going on the longest of trips just like the Model 3 and the Model S and the Model Y ask you a question do you wanna keep your battery at the top state of charge or do you wanna back off a little bit? The same thing can be true for the way our user interface will work. However, I think it's important to recognize the comment that was made on calendar life as being essential. We must have high capability to manage even at high temperature storage that the cell doesn't have a gassing problem doesn't have a cycle life problem based on calendar life fade. And right now lithium ion is producing around a 2% per year kind of degradation in very high temperature and much less than 1% in normal markets. So the average for lithium ion battery is we're losing about 1% a year for especially lithium iron phosphate as a pretty stable calendar life. We are going to target the same thing as we're validating our chemistries but 200 cycles of cycling capability is a relief but calendar life we do need to maintain a very long and strong capability there. Would you by absolutely agree I always feel that calendar life is one thing academics don't talk about and that's the one thing that actually matters the most. Yeah. A second question comes back to the specification you were showing. So you showed the greatly improved energy density volumetrically and graphimetrically. So the question has to do with the absolute weight of the battery as a whole because when you operate without the range extender you're still carrying the range extender as well. Yeah. Is there any impact on the system weight as a whole? Yeah, right now batteries today like a Tesla model three battery today has around 165 watt hours per kilogram. Our target is 300 watt hours per kilogram. So it's trying to maintain the weight so that we're not adding a lot of weight but we're trying to double the amount of energy. It's trying to but I do think we're gonna have some penalty. I think that there's it's likely that you're gonna see 50 to 100 kilograms extra weight to get to this goal. What I also see is that the most common market resident point that we've had so far is the truck, the pickup truck. Because the pickup truck has payload capability it doesn't have a lot of space to add range and the range need is much greater than what's currently installed. We think that the alignment of our targets is sufficient to design a proper battery. We think a pickup truck needs around a 300 kilowatt hour battery and the average right now is around 130, 140. So, putting a 300 kilowatt hour battery and a pickup truck means you can go back to closing the gap and you could tow with it. You can hill climb with it. You can go on long trips and you don't have to worry about all of the inefficiencies of drag coefficient, frontal area and weight penalizing you so much that you can't achieve the range goals that you have. Very exciting. Magy, last question before we have our panel discussion. So in your forecasting of the market and there's multiple segment, what do you think might be the range of ratio between your traction battery and your range extender battery? I imagine that it really depends on the application, how you split it. Yeah, we think in terms of physical space it's one third traction, two thirds range extender. In terms of range, we think it's 150 miles for the traction and a rough target of 600 miles for the range extender, EPA. I always talk EPA because it's so hard to go back and forth and it gets confusing. So, and by the way, that's the other really important thing to realize is I'm not an advocate for 700 or 750 miles of real world range. I'm an advocate for 750 miles of EPA range so that you can get the 400 miles that everyone actually commonly needs to take a six hour or seven hour trip regionally and that's where our targets have come from. Mujib, I think it's a very disruptive idea. So I think it's just like in Chaoyang's talk that people have to get comfortable with this idea that only a third of your battery is the traction battery. So I think it's a very, very exciting idea. So I see that Chaoyang has rejoin us and E as well. So it is a tradition in this seminar to have an open-ended discussion at the end. So maybe let me just get started and get the blood flowing here. I think what I'm learning from both of you is that you have identified a way in which the system complexity is a little bit higher but there is tremendous gain at the performance or behavior of the system at the systems level. So I wanted to ask, how do you find this optimal complexity? If you go too complex, there are a lot of other problem that shows up as well and have you reached that optimal complexity and what are some of the price you have to pay as a result of this higher complexity that you will have to mitigate for? Maybe I can ask Chaoyang to take this one first. Yeah, I think that's an interesting thought. Actually, what I really want to do is to simplify the system, right? So I do everything possible, try to get rid of thermal management, no cooling, no liquid and so on. And we will also try to develop new material that are thermally highly stable. So there is heat resistant and they will have enhanced safety without even the safety devices on the pack level. And because as a system level, whatever you do is it doesn't contribute to your energy and add the cost, volume and weight, okay? It's all management or system level is not good, right? Management is all cost money. So I think I believe one of the direction in the future really is to simplify the system at the pack level and try to make cells intrinsically safe, intrinsically capable and also intrinsically robust. In other words, whether you put a nail penetration or you kick it or you step on it, it just doesn't blow up. And on the outside of the cell, you don't have much, you even don't have liquid cooling, you can use aspirated air convection while you drive the vehicle because when you drive a vehicle, you get this air convection for free, right? And if you don't drive, you don't need thermal management. So I think there's ways, there are many ways, try to simplify the system. And we are moving towards that. Yeah, I wanna echo these comments. I think there's some insightful points that Chao Ang has raised. The higher the level of energy in a battery going up to two to 300 kilowatt hours, the lower the average sea rates and stress, the lower the thermal management needs, the more you can simplify a subsystem, the more energy you put on board, the lower, the less frequently you are going to hit discharge, depths of discharge levels, that's going to simplify and improve life. It's also very true that if you put six or 700 miles on board, you're not gonna need to fast charge that battery very often because you're not urgently needing energy, you're gonna charge overnight. And if you can give a battery a C over eight charge every time, that's great. So I think part of the idea where we might have added some complexity in power electronics. And I thought a lot about that by the way because it's like the most frequent thing in a battery that fails is the electronics and reliability, confidence, interval planning. The electronics are actually a big factor. But inverters for an electric vehicle are also electronics and we're expecting them to be 10 year life. And DC to DC converters for low voltage systems are in electric vehicles. We expect them to be 10 year life. Chargers are power electronics. We expect them to meet 10 or more year life. So there's no difference in all of those that I've mentioned in us putting power electronics in the battery to convert energy. If we can simplify other things, it actually is plausible that the electronics don't add a significant burden and we take away burdens like thermal management, fast charge capability, very high currents needed in fast charge are usually what are driving electrical distribution, contactor sizing, fuses sizing. Electric vehicles power profile is actually fairly straightforward. It's pulses of power with relatively low average numbers. It's the fast charging that's caused batteries to adopt strategies that are kind of significantly harder. And if we can eliminate that pain by just putting enough energy on board, that can help quite a bit. The last thing that I will compliment on Chao Ankh's statement is let's get a safer chemistry. The more robust and safe the chemistries are, the less you have to worry about the complexity of safety systems and other mitigating factors in thermal runaway. And so I kind of feel like we adopted some complexity, but we might have enhanced other and reduced complexity in other ways. Thanks, Mujib. So I really resonate with that. It's the optimization of the total complexity. And indeed you're adding some complexity in the DC electronics, but am I correct, Mujib, to also assume that the cost impact, again, is absorbed somewhere else by decreasing complexity elsewhere? Yeah, the cost impact for our range extender, we decided it, that's one of the reasons we decided to get rid of the graphite. Going after reduction in raw materials on sale resulted in a way to pay for the DC to DC converters and nickel cobalt, 22 bucks a kilogram before the price spikes have happened recently. We're looking at $1 per kilogram for our cathode chemistry. So we're going from 22 bucks a kilogram to one from $8 per kilogram to zero. Our goal is to make a destructively low cost range extender sale that has not great cycle life but very, very high energy density that will pay for the DC to DC converter and other power electronics, more than pay for it. I think that, you know, what the both of you have said is basically developing an engineering solution to break the constraint of conventional trade-offs, right? So you don't have to pay the conventional price, very, very exciting. Yi, would you like to take the next question? Yeah, sure, thank you, well, Mujib, really, really nice idea. From your idea in Chaoyang, both of your idea, I think it's kind of looking at the problem, it's different approach. Maybe I'll just try to be slightly provocative right here. Chaoyang, you're emphasizing, hey, let's go to smaller pack, right? I can do enable three R, reduce, reuse and recycling. And Mujib, you're going to the other one, you say, hey, I want to have my ring right there. So while listening to both sides, I say, wow, you know, all great ideas right here. And can you guys make a comment a little bit about, I mean, your approach and the other person's approach, right? I'm also thinking is whether this synergy or both of your approach, that can come out of today's discussion, yeah. Well, it's a little bit provocative, but I think it could be synergy to be built. I don't know who wants to take this question first. Not necessarily an easy one. I would like to compliment that I think we're on the same page for making the traction batteries smaller and more capable and with LFP. There's a lot of synergy in what we've said around the idea that the traction battery, the main purpose of an electric vehicle is the 150 miles a day. What I'm augmenting in Chao Wang's proposal is that let's add a range extender on board. And effectively that also can be a consumer decision. Remember an electric vehicle will be sold in the market where consumers right now might be getting one number and they choose to either buy an electric car or don't buy an electric car based on that one number. What we're offering is, okay, maybe the OEMs can offer small, medium and large range extender and they could offer 500 miles, 600 miles or 700 miles. And then you start to mitigate the cost factor. You give the consumer choices. I was taught when my career at Ford by a marketing guy that if you want someone to choose your product, don't give them one choice because then it's either in or out. Give them three choices and then they'll start thinking about which one of the three they like. And actually I really believe that. And I think range being such an important idea in electric vehicle factor and decision, if the consumer like my, I'm a consumer that wants to go everywhere with my electric car and I want to tow with it, I'm going to choose the highest range every single time. Other people that live in metro areas that don't travel a lot will be different. But what the range extender does is it kind of leverages, let's put the burden on the traction battery to be really robust, make it smaller. So in a way we're in agreement on that, make it powerful and capable and then give options, optionality on range by putting a range extender on board. And so Professor Chow-Yan, please. So maybe before Chow-Yan start, Chow-Yan, can I inject something here? Since Majin mentioned this, I'm thinking, well, what's engineering challenging or practical challenging right there? The range extender can be added on any time. Would that be a possible? Well, let's say you buy the 150 miles car. Then you say, well, you know, next couple of weeks I need this range extender for two weeks. I just go in and then check it out and install it. And maybe that's hard, maybe that's hard from both engineering and practical standpoint. Is that a viable idea Majin? Yeah, I mean, I think it is a viable idea. I think from my perspective, the range extender having, I mean, our goal is to make the range extender a bit about the OEM helping us decide the right way to implement because now we have three independent variables that used to be dependent. The three independent variables are how much daily range do you want and how much power do you want and then how much range do you want? And we can size according to those needs. And what I found in discussions with OEMs is that they want the flexibility of independently optimizing those because some platforms want a lot more power than others. Some want a lot more range than others. And we're giving the ability to kind of optimize that to the OEM in the sizing exercise of how the batteries put together. Yeah. So yeah. Yeah, I think our approach are striking similar at the fundamental level, right? Well, Jib has a own board range extender and I have an off-board range extender which is my past project, right? So they all try to extend range. And of course, I like to not pay for the range extender and not be able to carry that range extender and by consuming the energy, but whenever I need, I hope I have 10 minute convenience to get the energy. So I think that's a difference. I also, you know, and of course traction battery you consume less raw materials and, you know, you make the world a better place. So I hope, you know, when the Mojib's company succeed and someday he will be waiting actually to dismantle his own range extender and put it on the roadside and be able to share with neighbors, a few neighbors because you have like, well, 150 kilowatt hour second pack and that's like a fast charger. That's like a charger. You put it on the roadside, share with two or three neighbors and that's I think a pretty good thing to do. It's good though, of course. I like the concept. We could, environment. We can add another plug for people to plug into the range extender car and get a charge from it. Exactly. And assume, you know, your concept is going to be commercialized and we'll be adopted by, let's say, what a 20 million new cars to be sold, you know, in the United States and all of a sudden we have 20 million new chargers and then a year later we have 40 million new chargers. And I think that very soon, you know, we will have sufficient charging infrastructure. I want to make a comment though on fast charging and I've had some personal experiences. If I may. And I do believe I have a slightly different opinion about fast charging today. I do have a Model Y and I use fast charging quite often for the purpose of moving through trips that are more than the range of the vehicle. But what I found is that if I take real world into account, let's start with 306 miles is the predicted range of my Model Y. When I drive highway speeds, it quickly goes to 200 miles. At that 200 mile point, if I fast charge the first 200 miles, okay, maybe I drive 180 miles because I didn't want to go all the way to zero. So I drove 180 miles. Now, when I fast charge back up, I only go up to 70% because it's not going to fast charge beyond that because it tapers off. So I've actually returned about 100 miles back to my vehicle. So I was at 20 miles and now I go up another 100 miles, 120 miles is the real world number. Now I drive, I have to drive every 100 miles I'm stopping. And by the way, I've done that. I've done that in more trips than you know in including towing where I had to stop, take the vehicle off my Model Y, leave it in a parking lot, go ahead and charge and come back and pick up my tow vehicle because there wasn't enough range. So fast charging is, I promise, and people think, okay, I got a 300 mile range. I'm going to get another 300 miles by fast charging. That isn't the case. Because first of all, deduct for real world. Second of all, give yourself 70%. And when you find that every 100 miles you're stopping, it's way too often. And I've done it before. I've gone on very long trips and found that that detracts from the experience of electric vehicles. So even with fast charging and fast fast charging and notwithstanding, maybe you have to stand in a line. Maybe there's not enough power at the 20 stations to handle everyone getting the same charge rate. I've had those problems in Silicon Valley going to Lake Tahoe. You could have the problem that the fast chargers only give you, you know, the total station power divided by 20. And then you're stuck with like slow charging, not fast charging. But in irrespective of all those noise factors, there is the factor of not getting to 100% again, and then hopscotching every 100 miles. And that's why I'm not fully reliant in my idea around fast charging behavior. This is very nice. Yeah, yeah, we're all back to you. No, this is great. I think now the blood is flowing. This is great. Let me add to ease of provocativeness. And maybe poke a little bit if I may. So the both of you, Chaoyang Muji, I think paint a very promising picture, but there's still problems to be solved and hypothesis to be tested. In your mind, what is not completely known at this time for your technology that you're trying to demonstrate or do risk? Maybe what are some of the concerns people are raising in terms of, you know, I think it's clear that if this works, it will have great impact. But where are that, you know, final, you know, a couple of tens of percent that you still have to demonstrate in order to really make this extremely or fully compelling? I know this is a bit provocative, so I apologize if it's too much to the heart of the problem. Maybe I can ask Chaoyang Muji to take a shot at this. Yeah, okay, before I answer your question, you know, I think what Mojie said is very sensible. In the real world, you do have to account for various losses and so on. And now of course we require fast charging to reach 80% SOC, right? So this is all, you know, we have to maintain our high standard. But at the end of the day, you know, when I do research, I always feel like this simple truth and that is storage, storage, like as a number I give you, storage is 1,000 times more expensive than we're feeling. So I'm trying to find every single way to rebuild the energy rather than try to store and present. Now, having said that, coming back to Will's question, I think there's numerous challenges ahead of us, even I think to this day, our fast charging technology is pretty mature, reliable in the laboratory has been verified by third party and also has been made in packs in small quantity and so on. But in order to adopt it in the automotive industry, it still takes time, commercialization takes a long time. And first of all, you have four or five years this, before the, you know, between this design freeze and then eventually getting into the marketplace. And then you also have numerous other things to handle. So, but I think in principle, there should be no scientific issues. And in my case, I think it's all boils down to engineering implementation. And we are hoping there will be more people and more companies and capable engineers will come in and start to make this technology as slick as possible and get even lower cost. And eventually will allow us to enjoy a better work. Like I said, you know, fast charging really enable you to make batteries and affordable and sustainable. And that is the kind of idea that excites me and motivate me in the research. Chai, if I could, I will use your statement here to recruit my new students, make the battery technology more slick. I think that will resonate with many people and maybe also recruiting employees as well. If I can maybe just propose a question from my end, something that I thought of during your presentation that I think you demonstrate beautifully that the average degradation is not a problem as you go up to temperature. The time spent is minimal. Your fundamental study, I've read actually, I think was a show, your paper you wrote in 2017 in Journal of Power Sources just beautifully shows all the advantages of going to higher temperature. The one question I have is to me, one of the unknown is if the failure of probability, the statistical failure of probability increases with temperature. So I'm a big fan of using Y-ball distribution. Is it possible that when you go up in temperature your more rare events also increase and then that increases the defects parts per million at the cell level, maybe for failure or unexpected non-average behavior of the cell with temperature. Do you think that could be a problem? Fundamentally, I don't think so. I think it's going to the opposite because when you design your electrochemical reactions around the room temperature, we all know we are very sensitive to the temperature variation. Industry people say, well, the cell-to-cell temperature a difference should not be more than five degrees Celsius and percentage-wise that's pretty big. Now if I go to 60 degrees Celsius and for the same percentage, I can probably afford 10 degrees Celsius. If I go further to solid state batteries where you have, you're basically very tolerant to temperature, you can go even higher. Let me give you a analogy. Maybe it's not a hugely appropriate, but if you do combustion at 1,000 degrees Celsius you really don't care what impurity you have in there. You can burn anything, right? And whereas you try to do some reaction at room temperature, you need a catalyst, you need all this precious matter as in the fuel cell case. So I believe eventually as we go towards heat, resistant batteries and operating batteries at an elevated temperature, we will get a lot of easier environment to operate. And internal combustion engine is another example. I mean, if you consider such a small amount of heat produced from battery, I mean, battery run should be efficient to 90%, it's only 10%, let's say with the heat putter. If you take that small amount of heat and put it into the internal combustion engine, heat dissipation environment with a huge temperature difference, you don't need any cooling. You probably have to find a way how to keep the cells warm or temperature retaining. So I think it's a very different ball game. There's a lot of scientific open questions or possibilities waiting for us to explore. Chai, I think this is a very big shift in the mindset. So I think you're saying that with increasing temperature, not only the mean will move in the right direction, but the tail will also move in the right direction. So maybe perhaps increasing the reliability, the system for a large number. So I think that's a really large shift in mindset. I think that's very exciting to think about. Thank you. So Muji, same question. What are the unknowns you're trying to answer? What are the hypotheses you're trying to test and give risk for your technology? Muji, I think you're muted. Sorry. On the CELTA pack, we are de-risked and I believe we're okay on the Aries launch. On the Gemini battery, it's really two still research related topics that I believe are difficult. The first is that we're making a cell at a very, very high energy, that's the R. Current cell performance is just shy of a thousand watt hours per liter. And it still uses a flammable electrolyte. It still has lithium metal. It is a bit of a, I'd say it's a lot to manage. And we're trying to figure out the right sort of number of amp hours, how to manage gassing, safety, thermal runaway and not let that become a problem for the pack level. Even though the cathode is safer, we still have electrolyte, we still have lithium metal. We still have a lot of energy in one spot. And so we have to work our way through that and we haven't solved all of that yet. The second is as calendar life, it's really high temperature stability, avoiding degradation, fade and gassing. In the composition of a lithium metal anode, you can get like a lot of reactions are happening, side reactions are happening in the cell. So we haven't fully de-risked that. Power electronics and the pack architecture and coming up with like system design, we've actually de-risked all of that. The engineering is going along and according to plan, we're executing that. It's really around the chemistry. And what we're thinking about here also is we are about to launch a campaign to open up the field of companies that we wanna work with on the range extender chemistry that effectively if you're out there and you have a 200 cycle life chemistry with good performance on energy density and safety, come see us, because we can give you a path to automotive market because actually we're agnostic. We don't need to finish this by ourselves. We are willing to partner on the cell chemistry but those two areas are still, I would say I'm a bit concerned with especially the energy in one spot. The cell is still got lithium metal and it's still got liquid electrolyte. We have to work hard on that top. Mojib is still refreshing to hear you as a CEO of a startup to talk about the weaknesses as well. Not everybody's willing to say that. So really appreciate it. Yeah, I think we're at the end of the hour. Kujoo, do you wanna close this out by asking the finale questions? Yeah, maybe not asking questions just probably just share some of my, well, I would say very exciting for both of your talk. Share my excitement right here. So Mojib, consider silicon N for your case because you're looking for 200 cycle, silicon has some really high energy density cell right there, 400, 450 watt per kilogram, more than a thousand watt per liter. And Chaoyang, you know, you're thinking of doing actually engineering and so one layer can have system level impact. That's just super exciting. Both of you, I give my high compliment to both of you. And that's a real for my side, you should conclude today's event. Thank you, that's awesome. I think great system engineering is the best friend of great chemistry breakthrough. So we have a number of chemistry people here, a number of systems people all melted into one. So I think this is being a very accelerating discussion. Chaoyang and Mojib, thank you for making the time. We really appreciate it. So if I can have the close out slides please, Evan. So following today's excellent talk, we will have another industry academic pair, two weeks from now featuring the city of Blue Current, who was developing a polymer-based solid-state battery with silicon anodes. And then we'll also have our colleague, Professor Alberto Saleo talk about polymers, soft materials for energy storage. We're really delighted to have all these excellent academic industry pairing. This is one of the pillars of our initiative here. And please stay connected with us. We have a bunch of exciting announcements coming, exciting events. We just hosted our first in-person event with Professor Martin Winter from the University of Mooster earlier this week. So please connect with us via LinkedIn and social media. And for those of you interested in learning more about battery technologies and other technology for the energy transition, we have a number of courses that you can take from our professional education program. And with that, let me thank Chaoyang, Mujib, and Yi one more time for a great, lively discussion today. And I hope everyone a great weekend. Thank you. Thank you Chaoyang. Thank you Mujib. Thank you. Thank you. Good being with you. Take care. Thank you.