Time:2023.12.13Browse:1
Although graphite has been used as an anode material for power batteries for decades, its large volume, high weight, and physical and chemical limitations make it difficult to meet the high energy density requirements of electric vehicles. Therefore, silicon-based anode materials are gradually replacing graphite and becoming a new direction in the development of power batteries due to their ultra-high theoretical specific capacity.
Silicon Valley startup Sila Nanotechnologies recently announced that it has developed the first batch of process flow for large-scale production of silicon-based anodes. The CEO of the company stated that this new material has been named "Titan Silicon" and is currently undergoing certification for automotive manufacturers. It will be put into production at a new factory by the end of next year. According to the plan, the company's annual production capacity will reach 200000 units by 2026 and 1 million units by 2028, to be used for premium sales of high-end electric vehicles.
It is reported that the EQG electric SUV launched by Mercedes Benz in 2025 will use silicon based anode batteries provided by CATL, with an energy density 20-40% higher than its peers. It will use Sila Nanotechnologies' "Titan Silicon" as the anode material. EQG is one of Mercedes Benz's most expensive electric vehicles, and its prototype is currently undergoing testing in the Arctic. Public information shows that the energy density of EQG batteries will reach 800Wh/kg, nearly twice that of batteries of the same size.
With the development of lightweight electric vehicles, silicon-based anode batteries have become a new technology that major car companies and battery manufacturers are competing to develop. Since the 1980s, graphite has been the mainstream anode material. But graphite has a larger volume, weight, and energy storage limit. At present, high-end batteries have a silicon content of about 5%, but the theoretical specific capacity of silicon-based anodes is 10 times that of graphite, which is an important way to achieve high energy density goals.
Silicon based anodes also face challenges, as the volume of silicon expands three times after charging, and even low concentrations can significantly reduce performance. The mainstream solution is to wrap silicon particles in a certain structure to prevent expansion. Sila Nanotechnologies uses a porous shell to bind silicon particles, with an expansion rate of only 6%.
Ningde Times is leading in the field of silicon-based anodes and developed a 304Wh/kg sample battery in 2019. The Kirin battery adopts a silicon-based anode, with a maximum range of over 1000km. It will be mass-produced and delivered this year. Tesla also hopes to develop silicon-based anodes and acquire SiILion, but progress is unknown.
Porsche has reached a $6.5 billion agreement with Group14 Technologies. The collaboration between General Motors and OneD Battery Sciences is unknown as to who will make the breakthrough first. With the decrease in technology and cost, silicon-based anodes are expected to be further popularized.