Enovix’s specialty is a silicon-anode lithium-ion battery it calls 3D Silicon. The name refers to a proprietary 3D architecture and constraint system, as well as the cells’ 100 percent active silicon anode. Enovix has previously used this technology to create batteries for smartphones, laptops, smart watches, and mobile radios. Its latest development, however, is a super fast-charging EV battery that will put even the Lucid Air to shame.
The company has demonstrated its 0.27 Ah test cells to be capable of charging from 0 to 80 percent “in as little as 5.2 minutes,” according to a press release. They’re able to reach 98 percent capacity within 10 minutes. Enovix conducted the tests as part of a three-year Department of Energy grant program challenging the company to create high-capacity, fast-charging EV batteries—an achievement it seems so far to have met. Even after 1,000 charge cycles (some under particularly high temperatures), the 3D Silicon batteries retained 93 percent of their capacity. Enovix therefore estimates its batteries will last at least 10 years.
The silicon anodes Enovix uses are considered an upgrade from graphite anodes, which are typically used in modern lithium-ion batteries. This is owed to silicon’s impressive storage capacity. While graphite anodes can store about 800mAh/cubic centimeter, silicon can store nearly twice that at 1800mAh/cubic centimeter. Such a capacity comes at a cost, though: silicon lithiation can lead to significant swelling, which is highly dangerous, especially in the context of EVs. Enovix says it mitigates this risk with its integrated constraint system, which limits swelling to as little as two percent cell thickness after 500 charging cycles.
“EV manufacturers are in pursuit of batteries that support longer range, while the public and private sectors work to increase EV driver access to fast chargers,” said Harrold Rust, co-founder, CEO and president of Enovix in the company’s release. “We’re proud to support these goals to help electrify the automotive industry and demonstrate our batteries are an exciting option to power long-range, fast-charging EVs.”