90% in 15 mins: US firm’s new EV battery achieves higher charge with silicon anode

A new electric vehicle (EV) battery developed by California-based Amprius Technologies sports a silicon anode and can reach a 90 percent state-of-charge in 15 minutes.

The company has shipped its A sample cells to the United States Advanced Battery Consortium LLC (USABC), a collaboration between US-based automakers for improving EV battery technology, a company press release said.

The increased charge-holding capacities of EV batteries have removed range anxiety from potential owners' concerns. However, the higher capacities have raised concerns about the high charging times required to prepare the batteries for the long haul.

To overcome these concerns, EV makers are reducing charging times to those similar to fueling a gas-powered car. Since lithium-ion batteries take longer to reach an 80-100 percent state of charge than the time required for 10-80 percent, the aim has been to achieve the latter in under 15 minutes.

Amprius Technology, which has previously delivered quick-charging battery packs for the aviation and light vehicle markets, is now marking its foray into the EV sector with its A sample cells. These cells can reach an 80 percent state of charge in under six minutes.

The A cells delivered by Amprius have a high specific energy of 360 Wh/kg and a power density of 1,200 W/kg. When available commercially, these cells can deliver ranges far higher than current EV batteries offer.

While the USABC aims to achieve an 80 percent state of charge in 15 minutes, Amprius A cells achieve 90 percent in the same time frame. The company is also working toward achieving 1,000 cycles with its batteries, helping deliver an increased lifespan.

In addition to operating at temperatures as varied as -22 Fahrenheit (-30 degrees Celsius) to 131 Fahrenheit (55 degrees Celsius), the battery has also passed the nail penetration test, demonstrating superior safety.

https://www.youtube.com/watch?v=HGVKP99Z2vo

Amprius' batteries use lithium-ion cells, the most energy-dense solution available today, but with a slight difference. Instead of graphite at the anode, the company uses silicon, which delivers 10x energy capacity and a much better life cycle.

According to its webpage, the anode does not contain a solid rod but silicon arranged in a nanowire template with sufficient spacing between them. This facilitates volume expansion and easier and straighter paths for electrons and ions to travel, enabling faster charging rates.

Amprius began working on EV batteries after a $3 million award from USABC, a subsidiary of the United States Council for Automotive Research (USCAR), a technology company established by automakers Ford, General Motors, and Stellantis. USABC is working to develop next-gen energy storage solutions for automobiles, has supported Amprius efforts in this direction, and will now validate the performance of the A cells.

"We look forward to USABC validation of the A-sample cell performance towards showcasing the unique advantages of Amprius cells in electric vehicles," said Dr. Kang Sun, CEO of Amprius Technologies, in a press release.

"We believe our batteries are well-positioned to support all-electric mobility markets."

Through service agreements, Amprius has already secured 500 MWh of contract manufacturing capacity to serve customer demand, the press release added.

https://www.youtube.com/watch?v=petQar3bij8