So it's a real pleasure to welcome today's speaker, professor collaboration from the School of Material Science and Engineering here at Georgia Tech Lab. Got his bachelor's degree at Polytechnic Institute of St. Petersburg in Russia. Before coming to North Carolina State University where he got his PhD in material science, he joined Georgia Tech in 2007, where he is currently professor and Mifflin hood chair in Material Science and Engineering. And you can see has credentials here as well as co-founder and Chief Technology Officer of sila nanotechnology, which I just learned how to pronounce yesterday. As well as Editor in Chief of materials today. He's won a number of awards, including most recently, the Georgia Tech outstanding achievement in research innovation award in 2019. And is, is one of the most highly cited international scientific authors. In with that, I will turn it over. Although the Honeywell there. Thank you so much for the nice introduction. And Abdulla, I'm delighted to be here and share my thoughts on the importance of next-generation materials for all the future lithium ion batteries. But made with my phone, it. And so if you think about transition to renewable energy economy and the massive amount of lithium ion batteries that would require for this. There are many additional requirements that you have to realize and that are not met in a current lithium ion batteries. First of all, the minerals that go into lithium ion batteries have to be abundant. The materials have to be of low cost. The battery themselves, they have to provide fast charging and high-energy density. And energy density is important for multiple considerations. First of all, you have to have a longer driving range even for small vehicles. But in addition to that, if you go to high-energy density cells, on the cell pack becomes cheaper, less expensive because you simply need to build fewer cells. And certainly you have to make sure that the batteries they safe. So too, I've set the stage for the challenge. I want to mention that they had been only for commercially successful rechargeable battery chemistries in history. And of course, there is a lead acid batteries which are currently still use, utilized. And then there was the development of our nickel cadmium batteries, the nickel metal hydride and eventually intercalation type lithium ion. Then vendors for which he received Nobel Prize in Chemistry in 2019. And so each of these material innovation enabled by did it again, highest specific energy. So battery became lighter and they also enable higher energy density. So the batteries could pack more energy per volume per unit volume. And now I think the time is very exciting because SVC, the emergence of the fifth type of batteries, conversion type lithium ion, visual enable for the improvement and performance and at the same time, significant reduction in cost. For those of you who are less familiar with lithium ion battery reparations, I have this simple schematic. So you have two electrodes, cathode and anode. Cathode is typically comprises lithium because lithium is happy and the cathode, and it's easier and cheaper to assemble battery discharge state when they're, when the lithium is already in the cathode. And so once you assemble the battery, you charge it at the factory. So you move lithium from the cathode to the anode. And so when you allow the battery to do some useful work, some, let's say power your laptop or your cell phone than the lithium comes back to the cathode. And so the difference in electrochemical potential between the anode and cathode defines the cell voltage, the lithium ion battery voltage, and the capacity of the electrodes, or how much lithium each electrode can store defines capacity of the battery. And how fast you can move lithium back and forth, defines the power performance, or charging speed. Conventional lithium-ion batteries utilize intercalation compound, what it means. So you have this crystal structures that store lithium ion in the interstitial positions. So this is example of lithium cobalt oxide, the one that you use in batteries to power your cell phones or laptops. So when you move lithium back and forth between anode and cathode, irreversibly insert lithium back into the structure, or they call it intercalate. Intercalate lithium back into the crystal structure. And the process can be very reversible because there's very little changes in crystal structure, no changes in chemical bonds in an overall very nice system. However, it requires this multiple host atoms to two for lithium. And so it affects the weight of the battery. And it certainly affects the cost if you have to use expensive elements on, such as cobalt. And then there is a new type conversion type lithium ion batteries which people are exploring that have much higher capacity. It can smile, you need much fewer atoms to store a lot of lithium. On many of this conversion that materials can be built with abundant elements. The challenge is that during lithium insertion, you always break chemical bonds. In addition, you have dramatic volume changes. And furthermore, many of the conversion type electrode materials, especially the cathode, they tend to dissolve during cyclin. However, if you look at the changes in the lithium ion battery market for the last 30 years since the invention of the first commercialization of lithium ion batteries. You will see that initially for the first few decades, the price and performance has been steadily changing, right? Price had been reduced quite dramatically. And the performance was also steadily increasing. But in the last decade, even though you see or you hear about all the breakthroughs in literature, you will see that the price kind of stabilized in the sense that the changes in price and had become smaller and smaller and improvement in performance have also stagnated. So what do we do now? One way is to go to this new type of chemistry is for lithium ion conversion type lithium ion that will enable better performance hopefully within the next decade. And significant cost reduction. The additional issues with conventional lithium-ion battery chemistries. So for example, all the high performance, our cattle materials used in electric vehicles, they comprise nickel and cobalt. And supply of this materials in Earth's crust is very limited, especially if you consider commercially viable supplies. And so because of this significant increase in the band for the lithium ion batteries, we expect that within a decade, we will have, they will face a shortage of cobalt and shortage of nickel. And so as a result, the prices for cobalt and nickel might go up. And that is exactly not what you want to have, right? We want the prize for lithium ion batteries to go down over time, not hop. And so you can also notice that in the last few years already the prices for cobalt and nickel or skyrocketed the increased by two x. Furthermore, another one. Now the point I want to mention is the distribution of this metal crust is very non-uniform. Majority of supply of cobalt, for example, is in this Democratic Republic of Congo. In US and Europe there is no cobalt and very little nickel. So you also have a lot of nickel. You have much more nickel and cobalt in automotive, high-performance batteries. And supply of nickel is much larger, but you need more of it. And so again, they expect significant shortages of nickel. And so within a decade or so, the price my, I start going up. And so the current price is about $20 per kilogram. But again, it's almost twice as much as in 2019, few years ago. Now, in addition to that, there is significant price pressure to reduce the cost of the raw materials, minerals. And so many mines in developing countries, compromise on safety of workers, compromise on protective equipment, and sometimes cause major pollution. Nowadays, more and more automotive companies become very thoughtful about the supply chain. And they want to make sure that whatever cobalt or nickel, the US and the automotive batteries, they come from kind of clean mining companies that a company is mine. This minerals ethically, right without contaminating the environment, without making people sick in the process. But this is still an issue. And so I mentioned that the cost and performance of this new chemistry can be quite lower. Performance can be higher, and the cost can be lower. Uh, how can I say that? Well, if you look at lithium ion batteries and depending on the configuration that can be cylindrical, can be prismatic and pouch type. But if you open it up, you will see it consists of the same building blocks, right? You have current collector aluminum for the cathode, copper for the anode, you have electrodes. So anodes and cathodes it active material and some porosity because everything is immersed into the electrolyte and so leaky mind propagate through electrolyte. And then there's a separator that Practically separate anodes from cathode. And so you can have certain assumptions on the properties of this separate boils and electrodes. And you can estimate depending on what composition of the cathode and anode, what kind of energy density and specific energy or volumetric energy density you can get. And you can estimate that if you move this transition to purely conversion type chemistry, you can expect up to two times improvement in volumetric energy density and up to three times improvement in gravimetric energy density. And so both volume and mass matter. Because as I mentioned, the high volumetric energy density gives you a longer driving range in cars, right? And also low cost and light away. It is important for, let's say electric tracking, right? Because the battery's current batteries are too expensive for many applications, right? Under the expensive, expensive to buy that too heavy for many applications, it reduces the payload of, of drugs and so go into lighter batteries. I will overcome this challenge in addition for anything do you think about, let's say, flying cars. If you think about a drawn city, think about electric aviation. They need lighter batteries. In fact, if you look at the cost structure of the flight, more than 50% is the cost of the fuel. Even though the planes are not cheap, but majority of the cost is the cost of the fuel. And so electricity is dramatically cheaper. And the only thing that stops planes from using batteries is their weight. So if you reduce the weight by 2 three times, right? You may enable electric aviation miscible be good because of the reduced cost, but also it will be suddenly in grade four environment. In addition of this, a potential advantages, many elements that are used in conversion type cathodes, she has sulfur, copper, iron available in massive volumes and they're very low cost, especially iron and sulfur. And on and on and on it's own anode side is the silicon. And so we could do some predictions how much the price for the lithium ion batteries you may expect with certain performance improvements. And so maybe evolutionary reduction in the cost of manufacturing. And if you look at the cost of an actual cause and 2019, you will see that this data given for different battery chemistry is produced in different countries and different cell form factor. So it's not apple to apple comparison. However, you see certain trends. And you will see that batteries, for example, that have higher energy density, so higher, more watt hour per liter. I actually cheaper. So they have high performance, but they are less expensive by normalize, by kilowatt-hour. And why is that? Well, because the manufacturing becomes cheaper, you need to make few batteries, right? In addition, you have a less inactive material because you need to build fewer batteries. You need less separator, you need less electrolyte unit, less foils and so forth. So you have this cost savings. So you can predict when the transition from the intercalation type graphite silicon happens, what kind of performance improvement you can get, and what kind of cost reduction that you can expect as a result. And so, and our assumptions in this paper had been very conservative. And still they expect that on, with silicon anodes matched with high-performance intercalation type graphite as nickel-based or cathodes. All the cost of the batteries will be below 75 dollars per kilowatt-hour. And again, as I mentioned, is likely conservative. And if you look further along, when you have conversion type cathodes materials, then the price is going to be reduced well below $40 per kilowatt-hour. However, if you have to stay with intercalation type cathodes are the price is going to be much higher, especially if the prices for nickel and cobalt keep rising. And why it is so exciting is because you see that the transition to electric transportation is inevitable. Essentially at this price point, the cost to build mortal x Model S high-performance vehicle, right? Will be as low as that of the modern day comedy. But it will provide you much more fun to drive, right? It will provide you with cheaper fuel, right? Electricity is much less expensive compared to gasoline. In addition, you will preserve environment and prevent further climate change. So superoxides and the question is how fast we can get there. And as I mentioned, the development of high-performance silicon anode is the most critical milestone. So it has about 10 times higher gravimetric capacity compared to intercalation type graphite. It has about three times higher volumetric capacity at the cell level for the same cathode and the same separator foils and so forth. It provides over 40% energy boost. It is also widely, globally available. It is as much a silicon in the Earth's crust as all other metals and semi-metals combined comes from sand. The only problem is it is challenging to use. These challenges stabilize. So I want to highlight a few challenges. So when you insert lithium into our intercalation compounds, as I mentioned, there's very little volume changes. So there are very moderate stresses that occur. Silicon up, take so much lithium that it changes in volume. All this changes if you have gradient and lithium concentration across the particle, it may built up in tunnels, dresses, and if the stresses exceed the value related to fracture toughness of the material, you may have pulverization, right? So large particles will polarize and the smaller particles and the batteries may degrade. In other challenge is that when you litigate silicon, it expands so much, right? And when you have a lithium ion batteries, the anode, is this such a low electrochemical potential that all electrolytes that are currently being used become electrochemically are, they decompose? So when the volume changes in the material as small, this decomposition product may form a very stable solid electrolyte interface or ACI layer that prevents though the electrolyte composition. However, if you have such dramatic volume changes, it's very difficult to stabilize the ACI. So you have this electric chemical degradation of batteries induced by volume changes. And certainly if you particle swell so much, you don't want your battery the swell, right? You don't want your cell phone to swell. This have to be dealt with as well. And so when I joined George attack over a decade ago, I started to look into fundamentals of silicon chemistry. And on, together with other colleagues around the globe, we realize that small particles can be made stable, right? You will have no mechanical instability in small or nanoparticles of silicon. However, small particles always have very high surface area. So all these electrolyte decomposition now happens at much higher surface area. So you have much larger degree of undesirable reactions. Guys, you can have a faster degradation. Then we also realized that if you form composite materials, you can overcome volume changes at the composite particle level. Finally, we realize that if you have this core shell morphology of the particles when you have a shell and you have porosity, we didn't silicon that can accommodate the swell. And the outer dimensions of the particles may not change. If you have a constant out the dimensions of the particles, then in this case, ACI or this solid electrode interface can be made very stable. And so with this mind, the start, the company had founded two amazing co-founders with intrapreneurial expertise in hardware technologies. And this started in the Ford building in technology incubator space. And gradually grow the team from a few people to know about 300 people. Many interdisciplinary team of scientists, engineers, staff, all working together to commercialize silicon and other technologies related to the future of lithium ion batteries. We currently occupy three buildings in Alameda, California, so we move the company to Silicon Valley on like five years ago. And so and are also trying to secure now a much larger bills, much larger facility to build the Gigafactory factory, produce enough material to power up to a million electric vehicles per year. We were fortunate to receive significant support and trust of our investors and increase the company volume. So when we started the company, we envision that they wanted to develop certain type of product. We wanted to make sure that our product will be compatible with lithium ion battery factories present, past and the future. And so conventional materials, they typically micron scale. So we want to develop micron scale particles that would also skipped very small volume changes at the particle level in order to get this table ACI. And they also wanted, wanted to make sure that whatever we develop is going to be manufacturable economically at a global scale. What it means, it means that if you have, when you build large reactors, the lacI, the access should be inexpensive to build. It means that if you use some materials are precursors, they have to be inexpensive and available and massive scale. So it put significant restrictions on us. And so, but it was worth it. In addition, it's always easier said than done. We face multiple, multiple technical challenges. So when you have, let's say electronic device, the transistor. So atoms in a transistor, silicon atoms stay put right on the electrons move, right. And elegans can move back and forth and in transistor for billions of times without damages. However, if you have a lithium ion batteries, you have a host electrodes, a host atoms. Stay put, but lithium moves back and forth, right? And this is traditional intercalation, I believe your mind. So when you want to move to conversion type lithium ion, then every single atom moves during charge and discharge. And you have to make sure this motion is fully reversible. Because if any single atom loses its way to a side reaction, one out of 10000 atoms loses way inside the reaction in a single charge discharge cycle, then your battery will not last as long as it should. So we have to take different steps from very different industry to, to realize that vision to make sure this motion of atoms is fully reversible. In addition, the early realize that small experimental variations may hide the signals. So when you develop something right, you want to change one parameter and see how, how it affects ridge. And if you have very small signal, right, then if you have not very precise equipment, you're in trouble. And particularly if you have proposes that takes multiple steps, right? You have error in each step, then you see noise in the output even if you change some parameters. So we had to develop high precision reactors and make sure this we can control the process at a remarkable rate, much higher than they could do at an academic lab. We also learned that you develop new materials. In many cases there are no characterization techniques available to characterize them. So we had to develop our own unique metrology tools, our own unique characterization tools. They suddenly relied on a commercially available tools as well. But we had to develop our own, including our own software. I also want to mention that in many academic literature, key performance requirements are often overlooked. And as I want to highlight some of those, and many of these are even I was not familiar with when I develop technology at Georgia Tech at early stages. So we had to overcome and at the company. And so first of all, as I mentioned, swelling is very important and they have to make sure we can control it. So every electrode, even intercalation materials that change volume in each cycle charged, discharged, they expand and contract a little bit. And when we develop our materials, we wanted to make sure that they have control over this volume changes. And so the units that thickness change is very modern, very small. Otherwise it will be very challenging to get high-performance in a large automotive cells. And so insula could achieve that, could achieve that some time ago. In addition, there should be no long-term swell, right? Because if the batteries develops gradually, right? Eventually you'll, you'll come to a problem. Now if you have an electronic device, maybe your screen can, can pop off, right? If you have a car batteries, it's going to be disaster, right? Because if the combat the brakes, it has so much energy can go and fire. Your whole house can go on fire. That's very problematic. You have to make sure there will be no long-term swell. In addition, when the materials are processed, the lithium ion battery facilities are the current requirements is to reduce CO2, reduced emission, reduced the use of harmful chemicals. And so you have to make sure your, your acknowledge the particles in our case, would be compatible with the best technology on the market. In this case, water-based electoral process in and so she had to overcome it. And in fact, the performance of high, high-performance batteries with Scylla, scylla silicon Nano, it's actually better than high-performance batteries with otherwise analogous but with graphite anodes. Smallest, well, better performance. In addition, when you have a safety test for the batteries, typically what you do, you charge the charge the battery to high voltage and you hold it at high temperature for quite some time, and then you see the batteries swells or it doesn't, right? How much capacity the attains. And this test is actually cell-specific, so you have to build the proper cell in order to test the propellants. Certainly in academic environment, they can build high-performance large batteries. In addition, if you have this high voltage, high temperature hold, it has to retain that only capacity, but also has to retain high voltage. If the impedance rises, the voltage becomes smaller. It's a huge problem. And certainly there should be no end of life gas. And so when the battery dies and he does, you don't want it to explode. And this becomes very critical, particularly for automotive cells that have to last for, for decades. In addition, there should be laws of discharge, right? And so again, typically you hit the battery at certain temperatures and see look at the leakage current. And again, you have to make sure that materials you develop, in our case, silicon anodes would have a lower, or it is the same leakage current compared to the high-performance or graphite anodes. The calendar life, as I mentioned, this is very, very important, particularly for automotive applications, right? In consumer cells, the cell phones, people typically change them every few years, right? So the current real-life is less important. But if you buy a car, electric vehicles, right, any pays significant price for it. You want it to last at least a decade, preferably few decades, most preferably three decades, more. On. And another important parameter is that high performance and high performance in the fast charging at different temperatures, both high temperatures, room temperature, and also cold temperatures. And these are a lot of requirements that are not easy to overcome. And so when you report some use and civic discovered in academic literature, you probably don't test at all. In many cases, what we notice is that many, let's say, solutions that people thought are promising a completely unusable in industry because of some of these limitations. And so on. We significantly sources and again took us much longer time than they expected. But the company did develop a high-performance and outs and open replacement and the materials that would offer very good performance at high area login. So adult audience, how thick you elected this? And so it is important to, to produce the login that will be compatible with industry standards in it. The higher the better, because you will use less amount of inactive materials in the cells. And so high-performance characteristics, high login, hypo, low of a cycle losses, and high-capacity. Uh, so our materials of about five to six times higher gravimetric capacity compared to graphite. Because it's composites is not pure, silicon isn't as high. But in terms of the volumetric capacity improvement is almost, almost comparable to the pure silicon. And this is example of automotive cell and again, over 1000 cycles. So if you have a vehicle that would have, let's say, 300 mile range. 1000 cycles means it can drive for 300000 miles, again, typically sufficient for many applications. If you have autonomous vehicles, the demand will be higher. So you probably would need, let's say, something like 30000 cycles to satisfy this demand to have, let's say, a million mile battery. And it is also visible. The automotive sales loading is typically higher. And again, another important parameter is that you have this energy density gain, right? You have high performance. But you don't wanted to make, you want to make sure that at the expense of something else, not at the expense of safety. It is not at the expense of fast charging. And so in fact, the silicon because the entrance Athena compared to graphite and the time, the charge in time is related to diffusion through this, a little thickness diffusion of lithium ions. Athena the anode, the faster you can charge, right? And so we can enable is fast charging almost effectively for free. In conventional batteries. If you want to develop fast charging, You have to sacrifice something that typically people sacrifice energy density. And the cost you have a, if you want to have a fast charging, the battery has become cheaper, right? And the vehicles will be able to drive to a shorter distances. In addition, so we assemble our particles from ground top, so from liquid and gaseous precursors. And so we can make them of any shape that can make them spherical shape and spherical shape is attractive because it enables you to have very low tortuosity within the electrodes, right? So again, it's, it's very good in terms of fast charge and discharge. And this case we recycle the cells were quite some time and go on and showed that individual particles very fast. You can charge individual particles extremely fast rates. And then if you design electrodes properly, then you can also have very loath or towards its ear and fast charging available. And so the first product that the company developed is this silicon based composite powder that increase energy density of cells to about 20 to 40 percent that works today. It is fully compatible with old factories and you can build cells of any form factor from small cone cells in electronic devices to very large automotive cells. And there are many advantages to, to everybody. So for example, if you have a Gigafactory and supplies, let's say a million electric vehicles egos our technology. And now the same fact that it can supply Material cells to like 1.2 million electric vehicles, right? Or more. And so you have larger production without any investment in the CapEx or overhead. You also have reduced depreciation per energy, normalized by energy. And again, very important to reduce CO2 emission, right? You have to build a few cells per watt hours, so you have a reduced CO2 emission pivot hour. We were fortunate to build very strong partnership with automotive companies. Those two had been publicly announced. So both Mercedes Benz and BMW are going to build this amazing cars with the best batteries in the world using similar technologies. And they're going to be, to be absolutely amazing. I'm going to get one of those myself. And so once you solve the problem you have to overcome, you have to move forward. And so the next challenge is the cathode. How do you develop high-performance cathodes? And it is our equity challenge and probably even more challenging. So cathodes I mentioned they also conversion that Castle materials, the change volume, maybe not as much as the silicon, but still they're insignificant volume changes. The biggest issues with the cathode is that the cat is much more reactive. The conversion that Kathy much more reactive with electrolyte, it induces gassing. And also unfortunately, all conversion cathodes to some degree the dissolved during cyclin at some point of charge or discharge, they produce soluble species that dissolve and as a huge problem, right, you, you dissolve your active material. You also have precipitate on the anode and the resistance of the cells keep increasing. That's a huge problem. And sort of multiple solutions to that. And so there are multiple ways you can solve it at the cell level. Or you can do optimize an optimization of electrolytes. You can also, there's N particles. And particles I think is the most attractive approach because everything else can be kept the same kind of dopamine replacement as I mentioned. And so as I mentioned, there are two candidates for conversion that cathode materials that probably have the future. One is sulfur based, lithium sulfide. Another one is middle Florida based. So you can use this tool for base cathode in the lithium free state or the sulfur very cheap material. Or you can use it as a fully litigated state as lithium sulfide l2? Yes. And I think again, I'm going to share my personal opinions. Lithium sulfite is likely going to be material of choice for several factors. First of all, it's already in the full expanded state. It's much easier to deal with particles in the full expanded state. It can also be compatible with lithium three anodes and lithium containing anos, typically much more dangerous to use in factories. In addition, I think all these materials would have to be nanostructured similar the way that silicon is nanostructure edge. And they have to be protected from side reactions, Unions, shells. And the scene is again, have to be inexpensive, has to be very precise. And there should be no excessive force of an active materials in this composite particles. And now there is significant research on Tesla announced that right, dry processing of electrodes. And I would say lithium sulfide would be particularly advantageous to use with dry processing because it's more reactive, it's sensitive to moisture. So if you have dry process in is probably going to be advantageous even more for this particular technology. And so if you make, let's say these particles, lithium sulfate particles, as I mentioned during some point of charge and discharge, they tend to form poorly sulfides. Long-chain police certifies that dissolve into electrolyte. So how you overcome this challenge, if you use lithium sulfide, it has very high melting point. Very good thermal stability. Heat it up to, let's say 800 C. And then once you, if you have the thermal stability, then you can deposit all sort of coatings on the surface of the particles that would prevent direct contact between the electrolyte inactive material. And so that's what we did some time ago. And so again, if you have this nanostructured material with caution, protection, you can get some decent stability to, to, to, to some degree. Unfortunately, the coin isn't very stable. During charge and discharge, the particles change volume and typically coach and files at some point, then you have us start the solution. And the problem becomes particularly important for high logins. When you have thicker electrodes, you have more dissolution products, you have resistance Re, and so forth. And then you have to use some special electrolyte to try to minimize the damage is some of the electrolytes have this kind of self-repair March. Once you have this breakage in the shell, you can kind of repair it, can try to repair edge. It's not, they're effective though, but helps. And so another way to overcome it is to design this hierarchical particles. When you have multiple levels of protection and when you have nanoparticles immersed in some sort of matrix material, in this case, the overall volume changes are smaller, right? So you can prevent cracking of the shell and during, during charge or discharge. And you can also minimize probability of this 40 sulfate formation and leakage into electrolyte. So there are multiple ways to do it, but we developed very simple methodology some time ago. So effectively found that lithium sulfide can be dissolved and ethanol and methanol some, some, some organic solvents to decent degree. And if you have a, let's say a polymer and that can also be dissolved in the same solvent, and it could be simply dry. The solution. At some point, lithiums will start precipitation, right? As nanoparticles homogeneously. And then, because if you use a poor the marriage has, you know, polarity on the surface and lithium sulfate is polar. You're going to get caught into the polymer on the surface of lithium sulfite, right? It may prevent ripening of the lithium sulfide particles crystallization and the larger sizes which we want to avoid. And so then at some point you will form these clusters of lithium sulfate particles within this coordinate matrix. And because lithium sulfate is thermally stable, you can harmonize it right there. You're going to produce lithium sulfate nanoparticles embedded in this carbon composites, elastic carbon composites, which you can further protect with the shell. And so when you do this process, you can demonstrate that you can produce pure lithium sulfate and carbon composites without anything else, without any. Side products. And if you do microscopy, you can demonstrate that yes, you produce what you plan to produce. In this case, we demonstrate this relatively small particles, SAP 100 nanometers dimensions, but they can post even smaller particles of lithium sulfate embedded in this carbon metrics and further protected with this hotel graphitic shell. And so typically when you charge the batteries at high temperatures tend to degrade faster. But here we demonstrated again, you can retain very high stability and very high-capacity. Do it at an elevated temperature, 35, 45 C. And the difference between charge and discharge is the called the histories is very small. It means that the energy losses, even though you use conversion process, the notion materials, sometimes people believe that if you have conversion process, if you have to break a historic chemical bonds, you will lose a lot of energy. And this is, you do lose more energy, but it is still very small compared to everything else. As you have a small histories, you can have good energy efficiency. In this process. You also don't have to use suddenly carbon. You can use variety of other materials as a shell. And what he found that many oxide, they have very interesting properties. So we found that some of the shells that the title produce, they were not formerly conformal and they have holes. Yet they helped to retains stability of this materials which was very positive for us. And later we realized in collaboration with all emerging from Army Research Lab at had done some modelling. The realized that this long-chain poorly sulfides, they decompose from the surface of many oxides and form a much shorter chain polio sulfites that have dramatically low solubility in the same electrolytes. So you simply reduce dramatically reduce suitability of the byproducts that you'll potentially form. So maybe a good idea would be to combine some of these ideas together. And so you can achieve a good performance. And so the leaner, certainly better performance if you have this oxide coatings that they use and the composition of long chain polysaccharides for many cycles, for hundreds of cycles. Now, the next material which I want to mention for the conversion chemist is metal fluorides. It's a true conversion, so on. Essentially if you start with middle Florida and newly-created, you produce nanocomposite. You produced in this case, lithium fluoride and iron nanocomposites. And if you look at this reaction and you want to make sure it is fully reversible. You realize it's probably very hard. How can you make it fully reversible? Lithium fluoride has also very high resistance. It's very good. Dielectric material has high bandgap, so it's very resist. In addition, one of the biggest challenge you've found was that the interface between lithium fluoride and metal is high-energy. So lithium fluoride doesn't like to be near the, near the metal, or the metal doesn't like to be surrounded by metaphor that by lithium fluoride. And so they tend to our overall ripen or increasing dimensions over time and you have even larger mass transport limitation. And furthermore, both metals and lithium fluoride can dissolve into electrolyte at high voltages. And furthermore, you also have this metal nanoparticles that you produce. They often serve as good catalysts. And so they decompose the electrolyte and have all sorts of side reactions that again, I important to avoid. And so, and again, if you look at the more broadly, you probably need to use leaky the devotion of the material to be used in lithium ion batteries. And again, you have to nanostructure it. You have to protect it with shells, you have to confine the particles. And probably you're going to use iron as a metal and metal Florida because iron is very cheap, very inexpensive and you can have very high capacity, both gravimetric and volumetric capacity of these materials. And in addition, there are huge amount of waste products of metallurgical industry. And so this iron that is already treated with HF and has fluorine, is it available at essentially negative costs you have to pay to get rid of it. If you can use it as an input material for your metal fluoride particles, that will be outstanding that you can have very low cost production. And then one of the challenges that as I mentioned, this disaggregation of the particles and the high resistance of the lithium fluoride could be overcome if you simply nanny can find it. In this simple example, we can find this middle loaded particles within activated carbon and a very simple process, infiltrate precursor, converted the metal fluoride, and so then you don't rely on metal to conduct electrons. You have this carbon metrics to conduct electrons. And you use listener confinement in order to prevent ripe and separation, phase separation in metal and lead to Florida during cyclin. And then we demonstrated they are quite some time ago you can achieve hundreds of stable cycles and this high-capacity. You can also use different procedures. You can start with the precursors that would comprise both precursor for the carbon scaffold, a matrix material, and Picasa for the metal fluoride. So in this case we use a nanofibers, use electrospinning technique. You can use different techniques to produce spherical shaped particles or shaped particles of whatever shape you want. And again, you can have very high uniformity in these composites. And depending on, on optimization conditions, again, you can have high capacity and very stable performance for many, many cycles. So unfortunately, middle Florida, geekier, even if you figured out how to make them stable at room temperature, if you want to go to much higher temperatures, as I mentioned, batteries have to operate at elevated temperatures. You have to expose them to 7080 degrees C, right? And in this conditions, if you have metals that catalyze some side reactions becomes problematic. So those cells that have decent performance at room temperature, even 50 see typically the plummeted and performance decreasing capacity very rapidly in liquid electrolytes. And so the two challenges, the ways to overcome at either you figured out how to make perfect protective coating. So this and this materials didn't have any protective coatings. Or you can use electrolytes that do not react and they don't have this significant reactions with active material, do not dissolve these materials. And so then in this case we use polymer electrolytes and you could achieve good stability. Another advantage, maybe a synergy between polymer electrolyte, so many solid electrolytes and conversion type cathode is that many solid electrolytes that very well at low vol the load electrochemical potentials, they have stability issues at high voltages. This conversion that chemistry is that don't go too high voltages. They have very high capacity, but the voltage is smaller. But in that sense it's much more compatible with polymer electrolytes or with other types of solid electrolytes. Now you can go all the way to ceramic electrolytes as well. There have been lots of studies and lots of excitement about our ceramic solid state electrolytes. And there are pluses and minuses. And it's still unclear if this technology is ever going to be useful because ceramic electrolytes are much heavier and much more difficult to process, right? So you have to, if you want to make all ceramic batteries, you have to have the all ceramic electrons, you have to sinter them at high temperatures, which is expensive, right? You have to use very different processes, completely incompatible or partially isn't compatible with all production of lithium ion batteries worldwide. And people already built-in factor is the committed tens of billions of dollars, if not hundreds of billions of dollars to build all this giga factories around the globe, right? And if it's technology is not compatible with this factor is a huge problem for deployment. And so we thought, okay, it would be nice if we can use maybe solid electrolytes to prevent some side reactions. Maybe that would often better safety, but that will be fully compatible with conventional lithium-ion battery production. If you have, let's say solid ceramic sheets right there at the center, It's much more difficult. But what if you have electrolyte that may be liquid at moderate temperatures, maybe at 100 to 300 seats liquid because it has a low melting point, but it is a solid at room temperature or the operational temperatures. And so we found quite a few interesting electrolytes that can do that. And another interesting feature is that this electrical as that have very low melting point, fortunately or unfortunately, but actually it makes sense. Also lightweight, they have low density, so you have a density which is even lower combat density of liquid material and dramatically lower compared density of some of the solid that actualized people are considered in guarding the electrolytes. And so, so when you have this molten electrolytes, another interesting feature that you can have wonderful contact between the electrolyte and active particles. So if you have a good waiting behavior, you can whet your electrodes really well, and you can have very low charge transfer resistance. So in this study we used different types of materials be used both intercalation materials such as NCAM or nickel, cobalt, lithium nickel cobalt manganese oxide. Again, it's used very common material for used in electric vehicle applications. We use graphite because LCA, but we also use conversion type or lithium sulfate cathodes. And so because of the low melting point, right, there is no side reactions. If you don't have to heat the material is very high temperatures. You're active material and you elected won't react with each other, which is super nice. And they have multiple conformation of that. So we build this full cells and performance was eventually quite good. We can have high capacity. They have small histories, they have good overall characteristics. But you also notice that the cell degradation does take place. The challenge comes from the fact that, as I mentioned, all materials, even intercalation that cathodes, they have some volume changes. And during cyclin, you extract lithium from an SCM actually is, it swells a little bit and it contracts a little bit. Liquid electrolytes are very good and accommodating this volume changes. But if you have solid ceramic electrolyte, the commendations much, much harder. And so you don't overcommit. You have to figure out either have to design cathode particles that would have again various, even smaller William changes peripherally below 1% volume changes at the particle level. Or figured out how to deal with the interfaces and making sure it can accommodate some of the swelling at the interface between active material and electrolytes. And so even though lithium sulfide in principle has much higher volume changes, but if you assembled in a fully expanded state, it doesn't have to expand anymore. And in fact, they could achieve very good cycles. The ability for the lithium sulfide and the same technology melt infiltrated our electrolyte technology. And finally, I want to briefly mentioned maybe last two minutes or three minutes. Another technology which we developed at Georgia Tech, which I think is very promising. So conventional electrolytes as cells, as I mentioned, have a polymer separator that separates anodes and cathodes. And polymers are wonderful material. It's easy to process. The problem is that they typically have not very good thermal stability, not very good mechanical performance, especially at elevated temperatures. And if you miscalculated something, right? If you have some additional pressure within your stack and if you overheat yourself, the separate they can file, then you have a short-circuit between anodes and cathodes. And then it can have a thermal runaway event. You can have within a cell phones and God forbid, you may have it and let the car as a huge problem. Can ceramic do a better job? It certainly can. And the y and nanowires would be good. Because ceramic is a brittle material. Bulk ceramic is brittle, right? However, if you have nanofiber formation on now why information, brittle materials become very flexible. And so if you can build ceramic nanofibers, you can overcome these challenges. In addition, if you build fibers, then the small they become stronger they become as well. So you have high flexibility for small fibers and they also become much stronger. And so there are multiple conventional ways to produce nanofibers then unfortunately, they all are very expensive. And so they prohibitively expensive for electric vehicle applications, for, for better applications, particularly for electric vehicles. And so we discovered a fundamentally new scene that is mechanism based on minimization of the boundary of the chemical as strain energy, the boundary of the face transformation that allow us to transform bulk powders into nanowires. The simplified essentially you can put your powder is in a bucket, put some solvent, and then form a nanowires in a few hours, a few days, as simple as that. And so be demonstrated this process again as some time ago, they published the pipe and 1000 2017. And so this one simple example. So when you have a B metallic alloy between aluminum, lithium. So if you put aluminum into alcohol, it's not reactive. But if you put lithium into alcohol, it forms lithium alkoxide that dissolves instantly. And so if you make this alloys between lithium and aluminum, if you put them into alcohol, than lithium dissolves. But when lithium dissolves, the aluminum becomes much more reactive and it forms aluminum alkoxides. And what is fascinating is that they form this aluminum alkoxide in a form that's nanowires. And you can convert, if you wait long enough, you can convert this ALU particle into nanowires and they become dispersed in the suspension, suspended in this ethanol. And once you have the process, then you can choose different alcohols, right? Different hours as well. And you consume diameter of the nanowires. And by defining the size of the initial particles. You can also define the dimensions of the nanofibers. And so you can produce pretty long fibers with suitable dimensions. And if you have this alkoxides, you can also very easily convert that to a variety of other materials such as oxides, simply by heating them up, they have a very nice conversion. And so once you have this apologize, oxides, nanofibers, you can make ceramic paper out of them, right? You simply replace cellulose fibers with the ceramic fibers, produce the ceramic PayPal have very good properties. It has a very good waiting behavior, has a very high dipole on the surface. So electrolyte towards really well, and so you can have very fast charging in batteries. It also remarkable thermal properties. You can heat it to 800 seasoned go into Xing because it's ceramic. Again, Very good, very good behave or better applications. And so if your cycle, that cycle batteries, you will see small histories. You will see better behavior, high rate performance of this, of the separators. You can also incorporate them into polymers, make polymer ceramic composites will also have maybe not as good, then all properties are pretty good thermal properties. And you can also make ceramic nanofibers out of variety of other materials using the same technique, we demonstrated magnesium oxide, zinc oxide, cup oxide nano materials. So to summarize, I think the intercalation type lithium ion batteries are reaching their performance limits. And if you move to conversion chemistry, for example, silicon coupled with lithium sulfide or middle fluorides. You can overcome those limitations. You can enhance performance folder and reduce costs. Silicon Anna's approved to be commercially viable and scale up is in process. As solid state technology, in my personal opinion, has to be compatible with lithium ion battery manufacturing to have decent chance competing with liquid electrolytes. And I think coelomic electrolytes are ceramic separate as built with nanofibers. Red flags, if they can enhance safety, can improve performance and without any cost, without changes in the cost structure. And with this, I would like to thank you. Everybody who contributed to these studies have plenty of postdocs, have also amazing collaborators from both national labs and also here from just attacked Andrew Alexander. Alexander from mechanical engineering department. They haven't collaborated with for many years. And with this, I would also want to invite those of you who are working in materials related field to submit articles to materials today has a pretty high impact factor. So we're trying to catch up in Nature and Science, but please do submit your best work to our journal. It's also, we have a huge family of journals. So Materials Today's the flagship journal, but they have plenty of other journals in the family. And the impact factor of which of those escape horizon I got quite rapidly. And with this, I would like to thank our sponsors. I would like to thank David an Emmy for inviting me to give this talk. And I'm open for questions and I have to disclose the conflict of interest because this dependence on technology, like technology has been licensed the sila. So both myself and Georgia Tech as stakeholders of the company, think you do have time for maybe one or two questions. Thank you for your talk. I'm wondering as an editor, a person in industry and in academia. How do you feel about the, you talked, you touched on the balance of like what gets reported in academic journals. How do you feel about the structure of papers and if they're being prohibitive towards presenting the whole picture at different temperatures in different sizes of cathodes and things like that when it comes to moving the field forward, what are your thoughts on the structure of papers? And, and then I guess that the challenges are, of course, people want to report everything. The problem is that first of all, you have a pressure to publish a lot. The publish a lot. You don't have enough time to get all that has done. And there is a pressure from academic environment, right? You're expected to publish so many papers to get tenure, promotion, and so forth. In addition, there is a pressure from funding agencies they expect in three papers are two papers per year for the grant. Find a single student, right? It says it's very challenging to get it done. Furthermore, the size of the funding is typically insufficient to get all this has done. Many equipment is very expensive and many tests are simply, you have to have multiple people reporting. And so it becomes very challenging in academic literature to accomplish something like this. And I honestly don't have a clear solution to overcome this challenge. And maybe academic world is better to report on somebody revolutionary discoveries that may or may not be used in industry. And the industry has to judge what makes it makes no sense to use, utilize. Hi, thank you very much. Just wonder if you could just comment a little bit on the challenges for binders for silicon anodes. For example, we'll, we'll PVDF continue to be used for Silicon, etc. Yeah. So PVDF in the past been used for graphite, but it is not used anymore. So almost like 9599% of graphite anodes are using now. Aqueous binders, such as carboxylate tilde solos and others. And I think silicon atoms would have to use the same. So you have to use water-based solutions. And CMC and others are quite, quite well for silicon. And again, it depends that I'd see if there's any particle that look like it, I'll fight and behave like graphite. You can use the same bind this, That's alright, I can move the hour we're going to close here. I just wanted to thank collab one more time and wish you all a happy holidays and happy new year. Thank you so much.