Amprius has raised $25 million to commercialize next-generation lithium ion batteries leveraging Amprius’ proprietary silicon-based anode technology. (Earlier post.) Major new investors include IPV Capital (Shanghai, China), Kleiner Perkins Caufield & Byers (Menlo Park, CA), and Qian Neng Fund (Wuxi, China). Also participating in this round are previous investors Trident Capital, VantagePoint Venture Partners, Dr. Eric Schmidt, and Stanford University.
Amprius’ technology was initially developed at Professor Yi Cui’s laboratory at Stanford University; Cui is a founder of the company. (Earlier post.) Amprius’ first generation of silicon nanowire product can enable a battery with a 4x smaller anode that balances with a 40% larger cathode, resulting in a practically usable energy density increase of 40% compared to today’s best lithium-ion batteries, the company says. Amprius says that there is clear potential to reach increases of up to 200% or more in the future.
Although silicon has more than 10x the theoretical capacity of carbon (4200 mAh/g compared to 370 mAh/g), lithium ion insertion causes silicon to swell up to 400% when charged. This swelling causes bulk silicon structures to fracture, diminishing battery life after just a few cycles. Structured as nanowires, however, silicon is able to swell without breaking.
In 2009, Amprius received $3 million from NIST to support the development of a unique, high-throughput, continuous manufacturing process for producing the novel, nanostructured silicon-based anode material for lithium batteries.
Amprius says that its technology recently achieved key validation milestones for consumer electronics applications such as smartphones and continues to advance toward requirements necessary for electric drive vehicle applications.
Our recent fundraising will enable us to deploy our first commercial product, validate our manufacturing processes, and launch a global presence. We are delighted to have the support of new investors and the continued support of current investors as we embark on the next phase of our business.—Dr. Kang Sun, CEO of Amprius