Sila Nanotechnology has achieved double-digit lithium-ion battery performance gains, promising to reduce costs or increase the functionality of cars and mobile phones.

　　Sila Nanotechnology has achieved double-digit lithium-ion battery performance gains, promising to reduce costs or increase the functionality of cars and mobile phones.

　　Or in the past seven years, a startup company based in Alameda, California has quietly developed a new type of anode material that is expected to significantly improve the performance of lithium-ion batteries.

　　Sila nanotechnology emerged from the stealth mode last month and worked with BMW to put the company’s silicon-based anode material at least in some German automakers’ electric vehicles. In 2023, a BMW spokesperson told the Wall Street Journal that the company expects the transaction. Will result in an increase of 10 to 15% in the energy that can be loaded into a given volume of battery. Sila CEO Gene Berdichevsky said that these materials may eventually yield up to 40% improvement.

　　For electric vehicles, the so-called increase in energy density either significantly extends the range in a single charge, or reduces the cost of the battery required to reach the standard range. For consumer electronics, it can alleviate the trouble that mobile phones cannot pass for a day, or it may make possible next-generation features such as more powerful cameras or ultra-high-speed 5G networks that consume more power.

　　Researchers have spent decades improving the performance of lithium-ion batteries, but these benefits can only reach a few percentage points at a time. So how did SilaNanotechnologies achieve such a huge leap?

　　Berdichevsky, who is the seventh employee at Tesla, and Gleb Yushin, a professor of materials science at Georgia Institute of Technology, recently provided a more in-depth explanation of battery technology in an interview with MIT TechnologyReview.

　　The anode is the negative electrode of the battery. In this case, when the battery is charged, the negative electrode stores lithium ions. Engineers have long believed that silicon has great potential as an anode material. The reason is simple: it can combine with lithium ions more than 25 times that of lithium ions, and lithium-ion batteries are currently the main material used in lithium-ion batteries.

　　But this brings a big problem. When silicon contains many lithium ions, its volume expands so as to stress the material in a way that easily breaks the material during charging. This swelling can also trigger electrochemical side reactions, thereby reducing battery performance.

　　In 2010, Yushin co-authored a scientific paper that identified a method for producing rigid silicon-based nanoparticles that have enough pores inside to accommodate significant volume changes. He teamed up with Berdichevsky and another former Tesla battery engineer, Alex Jacobs, to form Sila the following year.

　　Since then, the company has been working hard to commercialize this basic concept, developing, producing and testing tens of thousands of various increasingly complex anode nanoparticles. It found a way to change the internal structure to prevent the battery electrolyte from penetrating into the particles, and it achieved an increase in energy density of dozens of increments, which was finally about 20% higher than the existing best technology.

　　In the end, Sila created a solid, micron-sized spherical particle with a porous core that directs most of the swelling in the internal structure. The outside of the particles will not change shape or size during charging, thus ensuring normal performance and cycle life.

　　The resulting composite anode powder is used as an embedded material for existing lithium-ion battery manufacturers.

　　With any new battery technology, it will take at least five years to complete the quality and safety assurance process in the automotive industry, so it is consistent with BMW's 2023 timetable. However, the cooperation between Syrah and the consumer electronics field is accelerating, and it is expected that there may be products with battery materials on the shelves early next year.

　　Venkat Viswanathan, a mechanical engineer at Carnegie Mellon, said Sila is "making great progress." But he reminded that progress in a battery measurement standard often comes at the expense of other people's interests, such as safety, charging time or cycle life, and so on. It is not always perfectly transformed into the final product in the laboratory.

　　Companies including Enovix and Enevate are also developing silicon-based anode materials. At the same time, other companies are looking for completely different routes to achieve higher capacity storage, especially solid-state batteries. These materials use materials such as glass, ceramics or polymers to replace liquid electrolytes, which help carry lithium ions between the cathode and anode.

　　BMW is also cooperating with SolidPower of the University of Colorado at Boulder. The company claims that its solid-state technology, which relies on lithium metal anodes, can store two to three times more energy than traditional lithium-ion batteries. At the same time, Ionic Materials, which recently raised $65 million from companies such as Dyson, has developed a solid polymer electrolyte that is said to provide safer and cheaper batteries that can operate at room temperature and can also Used with lithium metal.

　　Some battery experts believe that if researchers can overcome some large remaining technical obstacles, solid-state technology will eventually achieve greater benefits in terms of energy density.

　　But Berdichevsky emphasized that Sila's materials can now be used in products, and unlike solid-state lithium metal batteries, battery manufacturers do not require any expensive equipment upgrades.

　　As the company develops more ways to limit changes in the volume of silicon-based particles, Berdichevsky and Yushin believe they will be able to further expand the energy density while also improving charging time and overall cycle life.