“It’s an emerging technology in the very, very early stages of commercialization,” said Dean Frankel, Solid Power’s head of business development. “It just takes time from a scale-up standpoint.”
While some start-ups work toward perfecting and scaling up the solid-state battery, others like Sila Nanotechnologies hope to take advantage of current lithium-ion manufacturing processes to bring batteries quickly to market. Instead of creating a solid-state battery, Sila just replaces the graphite anode with one composed of silicon, a material that absorbs lithium ions about four times faster than graphite.
What’s more, most lithium-ion batteries with graphite anodes have a charge-rate, or C rate, of less than 1 percent. Start-ups developing new cells with silicon anodes say the C rates of their batteries are much better, a key differentiator to enabling an electric-vehicle future, since most people don’t want to wait around more than an hour for a car to charge when pumping gas takes just minutes.
“We can sustain a charge rate 10 times as fast as a conventional graphite cell,” said Robert A. Rango, CEO of Enevate.
The Irvine, California-based company creating a next-generation lithium-ion batteries with silicon anodes is armed with $111 million in funding, which includes an investment made last year by South Korea battery company LG Chem. Rango said Enevate, whose batteries have been in the works for 10 years, is about a year and a half away from the first commercial deployments of its technology, most likely in electric bikes and scooters.
Still, silicon anode batteries have one potential drawback: Silicon material swells, which means every charge causes the battery to deteriorate. It’s a problem both Berdichevsky and Rango said their respective companies have solved.
“Silicon does expand, and that’s been one of the challenges of the industry,” Rango said. “In our cells, we’ve been able to contain the expansion. Our cells have specifications that meet electric-vehicle requirements.” Those requirements? That a battery is able to charge to 80 percent after it has been charged and discharged 1,000 times.
The long development timeline for these start-ups is a sign of how difficult pushing battery technology can be. And while improvements in the range of electric vehicles is certainly one of the major implications of a better battery, successors to the current lithium-ion battery will most likely be initially found in much smaller items.
“You’re talking about a generational technological shift that has to happen,” Berdichevsky said. “In 150 years of batteries existing, there have been four commercially relevant chemistries to come to market. And every time you go to these new chemistries, they get harder.”