 Welcome to our next talk, energy storage of today for the energy of tomorrow. Short-air version is renewable energy are really hot shit, but what do we still have to research? What can we do? What can we do yet? And our speaker who has been here at Congress for 10 years will tell us about this. It's informed by his tendency to open up and take apart anything and everything. And this talk will be about various ways of storing energy, mainly batteries and what actually goes on inside them. So have fun with Sebastian and applause please. Okay, welcome to my talk, it's very full, I wouldn't have thought that, okay. Energy storage of today. In my Twitter timeline I tend to find news articles about what's better, a battery powered car, a fuel cell powered car, one of the both, and I had a look at all that and thought a lot of people are talking not very good stuff. They're picking aspects that favor one technology over the other, but they're not really comparable to painted image. If you put a penguin into the desert it doesn't do that well. If you compare it to a camel, the camel is much faster. If you take both and throw them into the sea, the penguins do it well. And you just have to look closer at things, so I thought why not tell you all about it. So why? Because I seem to kind of know what I'm doing. I studied chemistry, got my PhD, I started with organic and electrochemistry, and during my studies I sort of saw, yeah, no labs, nah, not my thing. And then I switched to fuel cell and hydrogen technology, worked for the university for money. And my job was to build small scale lithium batteries, so small that you can actually integrate them into a circuit board, you know, just order cheap circuit board from China, put the battery in there, and now you have an integrated battery, not soldered to the edge of the board somewhere. And I actually did my PhD at the Helmholtz-Centrum in Berlin, in the middle you can see the technical university, and the Helmholtz-Centrum has two sides, bottom right, Altershof, bottom left, Wanzi. And they have two very big devices, the BGR research reactor, which has been switched off recently, and we prepared for it and we turned it off, and in the next few years it'll be run until it's cooled down. In the other place there's the Bessey-2 synchrotron, where they do a lot of material science, and a lot of stuff about solar energy, mostly silicon photovoltaics, but also pyrus guides, and they characterize the materials and the structures there. First of all, when we're talking energy storage, you need two things, materials and a place to put them. The energy density has on the vertical axis the specific energy in watt hours per kilogram, energy per mass, which shows the lead batteries, normal batteries are relatively heavy. At the bottom you see capacitors, you know them from circuit boards, they're light, and on the horizontal axis we have the power per kilogram, which means how fast can I dump the energy out of there. Metal oxide capacitors, or so-called super caps, that's a key word for this, at least in this context of electromobility, they're dischargeable really fast, but they're technically not chemical energy storage, but physical, and what interests me personally is batteries and chemical energy storage, so gasoline, hydrogen, and we can look at this diagram, and my axis information just vanished, and this is the energy density per volume compared to the energy density per mass. Volume is the horizontal axis, yes, correct, I learned that in my studies, I learned in my studies that you have to label your axis or this sort of thing happens. So the vertical axis is the axis for the volume, and you see this, on the bottom there is methane and hydrogen, so it means that you need a big volume for less energy, and if you follow the line to the top, you see there is fossil gas, and this is what you know from the gas station, above them there is hydrogen in a liquid form, and on the very, very top you see that there is the usual suspects like gasoline and graphite, basically carbon, you also could burn aluminium, which has a very high energy, who of you has been working with a fire extinguisher with ABC, some of you even had a class D one, so it's above about 10 hands here, fire extinguisher of the class D are especially for metal burnings, because they are very hard to extinguish, you see this, they are really on top of this diagram, and you see here, well, I try it with the mouse, but it's not showing up, it's pity, in the bottom left you see that there is a lead battery, this is the lead battery, this is very low in this diagram, because it's very heavy in regards to the energy it's storing, and then you have the usual NEMH batteries, which you find in your probably decked form, the alkali batteries, which are not rechargeable, and then slightly below that the lithium ion batteries, which recently got the Nobel Prize, so again here the question, who has got a device with a lithium ion battery, so basically everyone, 2, 3, 5, 20, now the hands are getting less, but basically everyone has them, the technology is everywhere, so what, what means lithium ion? Lithium is an alkali metal, so the third metal in the period system, it has three electrons, and if you remove one of the electrons, it has three electrons, and if you remove one of the electrons from the atom, you get an ion, which means that it's positively charged lithium core, and this is actually storing the charge in the battery, these are the three people who got the Nobel Prize for the lithium ion batteries, the John B. Goodenough, there's a question if the parents had a twinkling eye with the bee, and Stanley Weitingham, Akira Yoshimori, and the Nobel Prize Committee has very nice documents on the topic, which I will now explain. This was the first iteration, where there was actually a block of metallic lithium for the anode. Which one of you had chemistry in school? Good chemistry? That's getting thin. Which one of you has thrown sodium into water? Ah, more than half. It burns and sooner or later explodes, so all alkali metals react that way with water, which means it's a bit of a problem to put a whole block of them into a battery like that, which is the reason why you shouldn't open these batteries, because even the moisture in the air can be enough to react with the metal in there, and then it's going to get warm and colourful. So, back to the battery itself. At the anode we have the lithium metal, and that lithium metal gives off an electron, or rather it is forced to do so while charging. When the battery is charged, the electron flows through the anode back to the other side, and in this iteration is stored in titanium disulfide. Titanium is a metal, too. Fairly well known. You know, that white paint for walls. Titanium dioxide is a very well known FG pigment. Here it's the software analog disulfide, and here at the very, we can see two volts of cell voltage. That's more than a normal battery with 1.5, but the problem was this thing chemically self-destructs over time. Next iteration, cobalt oxide. This is stable, and the battery isn't dead after two or three charge or discharge cycles. The cell voltage was a bit higher. We still have the lithium metal on the anode side, and at the end we had the innovation of getting rid of that metal block. The question was how to do that, and Yoshino found out that, hey, we can use graphite for the stuff you make pencils from, and it has this hexagonal structure, kind of like beeswax. And those structures are layered one above the other, and there's some room between them. And you can shove lithium ions between those layers. Lithium, with the atomic number of three, is one of the smallest elements you can think of, so it doesn't need much room. So you can store it in graphite or here petroleum coke. So not the coke for your nose, but the one for burning. You can store it in there and you don't have this highly reactive metal block or layer anymore, but something that can be handled much more easily. And the combination has developed into what we have in every device now. What's not my field of expertise, but has to be discussed, is where do you get that stuff from? Cobalt is being talked about a lot, because the main source is coltan ore from Central Africa, and coltan is made of columbite and tantalite, which are two minerals that are closely stuck together in the deposits. And they're mostly found in Central Africa, and the colmbite is also a source for niob, and the tantalite is tantalum. And these together also bring some cobalt with them. Nature probably thought or something about that, maybe didn't, just dumping them on the same place. So we can all get them from the same place. So the discussion next is where do we get all the lithium? That's mostly from South America and from China. Similar problem with the graphite. We need a certain quality of graphite for very high-performance cells. Main producer, China. So the question is, do we really want to start an economic war with China if they can just say, yeah, so no more battery component. And so you're not going to be able to make any batteries and won't have any. The podcast Methodisch-Incorrect has something about this. I listen to a lot of podcasts and some of you may or may not know the background about this. I can very much recommend, if you're slightly interested in science, to listen to this podcast. It's very interesting, very fun, and you can learn a lot. So then, what a battery needs is an electrolyte, which is the liquid between the both electrodes, because you need to have the ions inside something, because the metal won't just go from the one electrode to the other one. Therefore, there is the electrolyte. You use these carbonates, they are called. They have the property that they are very highly polar. And in addition to that, they are not acidic, because there are also electrolytes which use their hydrogen atoms and give them away, like with water. And if you put Kali metals into water, then that's a really bad idea. So it means that there is a certain condition to the electrolyte, and this class, the carbonates, they provide that. But you can see, they are hydroscopic, so they attract water, and this is the reason why you definitely should not open the batteries, because it will pull in the water. But in the best case, it just would lose its ability to store energy. But in the worst case, it will get warm and you get fire. For example, another way of this is this way. So, how have you put apart such a battery? Not that much of you, maybe 20. I myself have disassembled a lot of batteries from laptops and stuff. There is always a small PCB in front of it, which takes care that the battery is not going too low in voltage or too high, because if you put in too much energy, then these metal spikes will be formed as viscous. And they are thin and long structures for metal, which will grow at too high voltages. And then they are peaking through the cell, and you get a short in the battery, and you get this problem here. As any of you had such a device, this is a Samsung Galaxy Note 7. I see one hand. Maybe as a second. I think that's been for one and a half and two years ago, then these devices started just to burn from nothing. In parts in the pocket of its owner. What can be seen here, that there is an X-ray image of the battery. And there are the electrodes, and the big beer part is the isolator. And at some of the batteries, this isolator was too small. And through some hits from the sides, the faults were bending. And at one place just getting into contact with another one, and the battery had a short. So it got warm, it caught fire, and the result you can see in the picture. Not that good. This is something which you don't get rid of with any energy storage. You need to get them safe. But also the weight is taking its role. And lithium polymer batteries are in that point very good, because they are much lighter. So what's in current research are different materials for the electrolytes, where you get rid of the cobalt problem. There are plans, which you probably heard in the media from Tesla, that cobalt is being replaced with nickel, because they are very similar to each other. They are next by the periodic system. Also nickel has problems, which you probably know if you are allergic to it. So it's not without problems. But you have to look which problem is solvable and which you just have to take in. Very interesting, you also could replace the cobalt oxide of silicon, which means that the same material you built your ICs from, the silicon, you could prepare it in a way, so you can use it for batteries. Because it also has this grid structure, this hexagonal grid structure, where the ions can fit in. In fact, the place is even a little bit bigger than the cobalt oxide. But this just works for once, because the silicon is integrating the lithium in itself. It gets physically bigger. When it's going to be discharged again, then it gets smaller and cracks are forming. So you don't have a nice plate as an electrode, but you have some crumble. This is one of the fields of current research. How to solve this problem, so you could use silicon and get rid of the problem to discuss the things about cobalt and Africa, how is the ethical situation. With the electrolytes the same, methyl ions. There is an interesting story to the metal ions in the 80s. When there has been the fundamental research to the batteries, then we thought about sodium as a metal for transferring the charge between the electrodes. No one knows something about this, so right in the moment, in the public press, but there is still research. These batteries are working quite well, but they need very high energy. At room temperature they don't work. It's probably something for trucks or for energy storage at some power plants. But at home or in your device that's not an option. But in principle it's pretty similar what you can use. Also sodium there is plenty of. You have this in every ocean. You can just get the salt from the ocean and then use it. And you would get rid of the problems being dependent on China or South America. Something about hydrogen, that's not that much my topic, so a little bit higher level overview. This is a state diagram of hydrogen. Hydrogen is special. Which one of you knows from camping for example these gas burners you can run on cartridges or those big propane bottles? Yeah, 80-90% at least. Which one of you has accidentally opened the valve and then screwed off the hose? How many of you? Yeah, a few. Okay, a different example. Which one of you has refilled a lighter? If you don't do it right then there's a hissing noise and it gets cold. So in chemistry we call this the Joule-Thomson effect. If you remove the pressure from a liquid pressurized gas, so a pressurized coterie, open the vent and the internal pressure drops down to atmospheric and it gets cold. With most gases it's that way. Not with hydrogen. Hydrogen gets hot. And that's bad when you have a leak in a hydrogen tank. You have to be careful about that. For example in space travel where you're filling rockets with the stuff, you have to watch out for this effect. There are three filled in areas in this diagram. Number one to the left on the orange line is the liquid storage of hydrogen. And you can see mainly if you look at the temperature axis at the top, we're at minus 260 degrees. There's not much room until you hit absolute zero. This is also called cryogenic hydrogen because you can't liquefy hydrogen above the temperature described by the orange line. If you make the hydrogen warmer, it'll still be under pressure and still be highly compressed and relatively dense, but it won't be liquid anymore. And if you heat it even more to hit the area number two, you can see what happens at what pressure and what temperature. And you have about 500 bar in a pressurized gas bottle like for welding. And those commercial bottles are usually 200 or 300 bar. This diagram goes up to 1000, which means that you have to do some convincing to compress hydrogen. And at the top, the area number three is the transcritical area. A critical point is the point above which the difference between the states of liquid, salt and gashes sort of melts together to one state where the different phases can't be differentiated anymore. This isn't actually liquid, not really gashes. It's something in between, but you also need very low temperatures. That's one of the aspects that are not that good for using hydrogen as a fuel because you have to cool the stuff and keep it cool. That means a lot of energy and infrastructure and insulated vessels. If you poke a hole in one of them and it gets out, that's a lot of, that's very problematic because of the Joule-Thompson effect which heats the hydrogen up. And this also means that if you think about where hydrogen can work, well, as far as I see it, mostly in situations where you need large amounts of it at once and known places where you have time to fill up. So the whole thing, I need five minutes to fill my diesel at the gas station but I need 10 or 20 with hydrogen and then the hydrogen, the gas station has to sort of regenerate and cool down. You can do that but for an individual transporter person it's completely useless. I'd say on a large scale you simply can't do it due to dangers or whatever. But maybe buses, ships, possibly planes can be fueled by hydrogen because they fly or move from a few known points. You don't have to put gas stations everywhere but you have a few certain points where you can keep the hydrogen and you can deal with it in a safe manner. With individual transit, yeah, you can do it. Some people are doing it. If it can be done at scale, I don't know if that's a good idea. But saying hydrogen is useless as a whole or is too expensive, needs too much energy or is dangerous, that's also wrong. You have to look at your use case and see what you can deal with and then you can say I'm using this medium of storage or this one or this one. With batteries it's the other way around. You always have to carry the material around with you. You have the battery, the electrodes, cobalt oxide, graphite. It's always there. You have to carry it around. And the lithium ions just move from one end to the other. Doing that they either absorb or give off energy but the mass of the system is constant, no matter how full it is. In school we had this joke along the lines of is an empty battery heavier, lighter than a full one? Well, there's less electrons in it. And if you look at airplanes, you maybe don't want to build an airplane. That's a gigantic flying battery because you always have to drag the weight around with you. Then we have the way nature does it. The left side is a rough scheme of what every plant does. The sun lights up green stuff, the light reaction part of photosynthesis happens, CO2 and water gets fixed and O2 is dumped overboard. And at the bottom we have sugar as a way of storing the energy and large organic molecules. To look at it in slightly more detail, it looks like this. You might know this from biology in school. You have the two step photosystem and the absorption of both. Here you can see pretty good why leaves are green. Well, they absorb blue, the higher the peak on the graph the more of the light is captured. Also the bright red part hits the center of the photosystems. This energizes the molecule and via the very long cascade of different complicated biomolecules the energy is passed along and the cell makes its energy from that. This is very hard to reconstruct. Though some of these circles there shown there are being isolated and looked at. How does it work? What enzymes are involved? What proteins are involved? Sometimes you have metal centers. How does this work? What can we learn about it? And maybe can we do this in an easier, in an easy to do system? So peak gets higher, means it absorbs more energy. And in the middle there's this valley that's green, which means that green light isn't absorbed. So the leaves look green. And another vision is to say, okay, can we use this as a model and emulate it. We can make an artificial leaf, which is sort of the name of the category of this stuff. And we can say, okay, we're going to take our material, dunk it in water, put it in sunlight. And we might be able to analogous to the plant with its leaves, split the water into a hydrogen and oxygen, capture the hydrogen and either liquefy it or use it in chemical industry. And through various reactions stick it together to larger energy carriers. And maybe at the end you might be able to produce what we know as gasoline or fossil energy carriers, but made out of sunlight. We don't have to dig out a million year old stuff from the ground, but we can just make it ourselves. So as far as the model goes, this is a climate neutral or CO2 neutral fuel. We're still burning an organic chemical or you can run fuel cells off of it, such as with methanol. You have diesel, gasoline for just normal combustion engines. But since we extracted the CO2 that we're producing here from the air before and built the fuel out of it, it's just liberated again and it's a zero-something. The biggest problem is that CO2 is present luckily in fairly small amounts in the atmosphere. So it's fairly annoying to get it out of the air to actually run this reaction. So that's a big field of research to just try to determine what we can actually do. Another version is that what is done so far and working pretty well, that you use sunlight and there you have in the meantime working very well silicon solar cells having a very high efficiency and then you use the current which is coming out of it and doing electro synthesis. And so you put electrodes into water, letting the current flow and isolate the hydrogen at the oxygen. And the worst process is what's known as an... What happens is we're taking this material here, it's called yellow. It's actually a yellow powder in real life which has worked best so far. And you hit it with here, we have rainbow colors to just make that obvious. We hit it with sunlight, the yellow material absorbs some of it but passes the yellow and red long wavelength stuff which then hits a conventional silicon solar cell, dumps its energy there and both together can be used to produce enough energy and voltage to run the water dissolution directly in the device. If this can be done at an industrial scale, we would be able to solve at least some of our energy problems or at least help with that. Then there's other avenues of research, how much energy can I actually pull from this? How much surface area do I need? I still remember a rough number from one of my professors. Per day you'd need to install a few hundred square meters of solar cells until 2050, 2400, to achieve the goal of complete climate neutrality by then. It's of course completely illusory. You have to produce these materials first, you have to produce the solar cells, you have to stick them together into modules, have to screw them onto rules, wire them up, some are going to break. It's a vision, sounds good, but then there's the question how do we do this in reality? Probably wouldn't work for us, but for some parts of the earth it can make a significant contribution. Then I have a press release here for you, it's from this summer. And this is an attempt to generate what they call kerosene directly from sunlight. They're emulating a fossil fuel. But here they're not doing it chemically, but just by concentrating sunlight. In the center of this mirror there's a reactor that is brought to very high temperatures, 1200 to 1500 C. And using special catalysts a reaction happens where CO2 is taken from the air and together with water it is converted into a fossil fuel emulant that is de facto CO2 neutral because you pull the carbon that you're burning from the air yourself. But here it's the same problem, if you just pull the CO2 from the air, there's not much of it. And I believe this device produces low double digit milliliters of fuel per very sunny day. It's not much, and this is a fairly large device. It's 6-7 meters in diameter, it looks quite heavy and it looks hard doing this at scale. You can't just do it. So then I want to bring this argument here. Who should pay for that? This is what people ask. And this is more a question for you to take back home. What's about all of that energy which everyone took advantage of till now? By now we have something about 300 ppm, 350 ppm carbon dioxide. Oh, it's 400? So the audience said it's more. In any case it's much more than the 100 something ppm. So it's gone from 200 to 400 ppm. We've gone from 200 to 400 ppm in the last 150.000 years. Oh, it's just 150 years. As I said, where I want to go is that this 200 ppm difference is sometime been inside of the ground in form of coal or oil. And this translates to an amount of energy, which then translates to money in principle. And that's from what generations of people profited over the last years. And they produced waste in the air. This waste paid for a lot. So now thinking we can't pay for this to bring it back in the ground. That's might be the case. And it might be the case that's the big amount, incredible big amount of money. And I actually thought about this. And I can imagine that it will cost some decades of the gross domestic product of the world. So we can't pay for that in a few years. We don't have that. We already spend the money. I don't know. That's a political question, a societal question. This is not my department, but certain here are people who think about this and know about this. And I would like to get them here on stage, one could say. And we should ask who profited from this. Basically every discussion we talk about, we have is all about the distribution, the quality of people. So in the end chemistry is an interesting thing. And it's not just what's loud and stinks. One also could do stuff as a computer affirmative person. And basically you're working with electron clouds flying around atoms and then doing predictions how it's actually performing. So currently the predictions aren't that well. But it's better than 10 years ago where we calculated 10 years, 10 weeks for one calculation which is now going faster. And because I've seen that there is this discussion, this argument over electric cells and cars and hydrogen in cars. And basically we want to sell something now. For people it counts what's paying out now, not in 10 years and what's the problem in 10 years. So I want to end with one of my most consumed podcasts, which is called Methodisch Incorrect, a German podcast. Also the podcast Forscher Geist and also the Mikroekronomen. I listened to two or three episodes of them, which are working or telling something about the economic impact of energy and renewable energies. Also you could look at the presentation I did at the camp in the summer, where I talked about how to make hydrogen out of sunlight. And there also was another talk, not by me, which was called Power to X. So how to make basically every kind of fuel from X. And on the congress there will be two more talks, which I find interesting. We can't afford to just bury all batteries that are broken. We just do not have the resources to even source these materials in the first place. Tomorrow, no, on day four on the Chaos West stage, there will be a talk about what happens when a battery breaks. What is the aftermath of that? As I said, if anyone says I have something very interesting over here, come to me, come towards me, do approach me. You can contact me under these contacts on the screen. I cannot really talk over the HZB podcast, but yeah. This podcast is produced by Holger Klein, which actually did an interview with my group leader. And he's doing this podcast. Also, there is the retired institute leader, Thichter, who also contributed to the place that I had fun on this field of research, so that I produced results and that I now have the knowledge I can share. At the end, the feedback, I would like to know, was this too technical, too chemical talk, or would you have known more about it? One of you seems to want to know more. This is my deck number here at the congress. If I pick the call, then it's nice. If not, try it again. There is an email address, which I'm looking at during congress and maybe later. Here you can write me if there are questions. Also, if you look at this talk in the stream or later at home. So now we come to the Q&A. So we have about 10 minutes of Q&A. Everyone who enters before this do use the left door and not the one you entered in. There will be angels showing you the way. If you have questions, then ask the microphone. If you do have questions, approach the microphones and make yourself be seen. Your questions will be answered in some order. Thank you for the nice presentation. If it's such a big problem, storing hydrogen, could you not just distribute it over the current gas network? It's thought about that. Actually, fossil gas contains a bit of hydrogen. But the problem with hydrogen is it's special. Because it's diffusing through the pipes. And if you would fill the gas network with hydrogen, then you would not get the same amount out of it. Also, it would bind to basically all metals. So the metals aren't really deformable anymore. They get very breakable. So it's not just diffusing through the pipes, it's also damaging it. You could not use the current net for fossil gas, natural gas for hydrogen. Another question from the internet. How about the efficiency of storing energy? For example, cooling and all these factors which consume energy. Do batteries not overall do better in that? This is a question I can't answer right now. Because there are a lot of questions going into it. For instance, the liquefying of hydrogen, you need lots of steps. When charging a battery, it's just one. Also, it's dependent on the boundary conditions like temperature and pressure and stuff. So I can't really answer this now. Thank you for the interesting talk. Another question regarding hydrogen. About 35 years ago I was at the Max Planck Institute. A hot shit back then was storing hydrogen in metal tanks. Where it was found the volume of storeable hydrogen was increased by 40% in some metal canisters. You could really safely store it with that technique. Is this being researched on more or is this dead? There is still research on that. I'm not really inside of that field. But as mentioned before, basically hydrogen is bounding, is building hydrates with all metals. And you might then use palladium or platinum, which is very expensive. But here you would get a lot more volume of hydrogen inside of this hydrate than in just liquefying it. So if you press it into the hydrate under heat and reasing it with heat, you can store more hydrogen than liquefying it. But actually it would get very expensive. So there's research on doing it with more cheap materials. People are thinking about doing a refill system where one could produce filled hydrate storages and sell them as charged cells. Use them inside one's device. Then they are discharged, you bring them back to a refilling station and there they get filled, you get a new one. So you wouldn't have the problem that you need to transfer this hydrogen liquefied under high pressure. But here again this material would cost a lot, this storage would cost a lot. Microphone number three please. In the first half of 2019 the university in Kiel made a battery out of silicone and sulphur with gigantic numbers that got thrown through the internet, for example ten times the capacity and all these things. From the research world are there any news regarding that? I can't tell anything to that. I haven't heard about it. I know that there is research on sodium. How about zinc oxygen batteries? Do they have any sort of future? This is also a combination of materials which I do not know. There is zinc air batteries they are used but I don't know if they are available in a rechargeable version I don't know. And I don't know how it is with the oxygen which you need to get in and out. Handling gas is more difficult than solids and liquids. This is all I know. Two short questions. First of all how come hydrogen warms when expanding? Second of all I would be interested in comparing photo electrolytes and classical electrolytes in efficiency. It's just heating up. That's the way it is. It's a property of hydrogen. If you then would go to quantum mechanics and this is the wave function. How do hydrogen atoms interact with each other? Then you can model on how this is. But this is just a special property of hydrogen. With the most others it's not. But the most gases you use they are more atom gases. Hydrogen has just two atoms. But with butane and stuff it's up to ten atoms. So it's very different. The other question was about the efficiency. So I can tell you a rough estimate that with solar cells have an efficiency of 28%. The electrical... We are sorry unfortunately we did not get that part. So you get an efficiency of one or two percent reliable but there is a big difference to theory. Unfortunately we do not have any more time. There were multiple more questions so apparently you held a very interesting talk. He's available later on to just approach him. It's nice that you've all been here. Thank you for the questions and thank you for your time.