IEEE Spectrum began the year with an online article by David Schneider, “To Boost Lithium-Ion Battery Capacity by up to 70%, Add Silicon.” It includes the following update on Enovix:

Ashok Lahiri, cofounder and chief technology officer for Enovix, along with two colleagues, described the company’s battery technology in detail in these pages in 2017. At the time, Enovix planned to borrow fabrication techniques from the semiconductor industry to construct batteries from thin wafers of solar-grade silicon. But the company reconsidered that strategy after grappling with how to apply it to larger lithium-ion batteries for vehicles. “We realized that the solar-grade substrates could not scale,” says Lahiri.

So Enovix revamped its approach and is now using a metal foil instead of a silicon wafer as the substrate for its battery. The overall geometry of the battery, however, remains the same. It’s just built differently—by stacking components, says Lahiri, who explains that keeping the anode stack under high pressure inhibits the expansion during charge and allows the anode to be made entirely from silicon and silicon oxides. “We think our battery will be from 30 to 70 percent better, depending on the application,” says Lahiri.

The photo-illustration for the article (also used in this blog image) is by Edmon de Haro.