Porsche investment could unlock up to a 50% boost in EV battery density

Luxury automaker Porsche just made a big bet on futuristic battery technology.

The German carmaker led a $400 million investment in American startup Group14 Technologies, which makes advanced batteries using silicon. Adding silicon to the anode (one of the key parts of a battery cell) could significantly improve the driving range and charge time of electric vehicles, two crucial metrics for their broader acceptance. But the technology is generally expected to be years away from widespread commercial adoption.

Group14 aims to move up that timeline — its silicon anodes are on track to get into electric vehicles by 2023, CEO and co-founder Rick Luebbe told Canary Media.

“Silicon batteries are here,” he said. ​“The technology is proven. Now it’s about scaling to meet the demand.”

Group14 already has a factory outside of Seattle that produces 120 tons of silicon-carbon composite per year. But the new Series C funding will bankroll construction of another factory in central Washington, which will produce enough battery materials for 600,000 EVs per year when it’s fully operational in late 2023. A South Korea facility jointly developed with SK Group is coming online this year.

Billions of dollars are riding on EV battery improvements. Several companies are chasing solid-state technology, a ​“next-generation” approach that eliminates the liquid components that sometimes catch fire in today’s lithium-ion cells. In the meantime, though, silicon anodes are an improvement that can be dropped into the types of batteries currently in use (or into future solid-state cells, when they arrive).

Silicon anodes hold more energy than conventional graphite anodes. That inspired scientists to replace some or all of the graphite in the anode with silicon.

But this improvement doesn’t come without problems. Silicon expands and contracts as the battery charges and discharges, and those fluctuations can damage the battery. The trick for companies including Group14 is to harness the energy capacity of silicon while minimizing the damage it causes.

Group14’s recipe, dubbed SCC55, uses ​“hard carbon-based scaffolding” to keep that silicon ​“in the most ideal form – amorphous, nano-sized, and carbon-encased,” according to the company’s website. In other words, the silicon sits in a minuscule scaffolding structure where it has room to expand and contract without weakening the structure of the anode, Luebbe explained.

Achieving an ideal anode requires years of complicated laboratory science. Group14 grew out of a company called EnerG2 that focused on nanoengineering synthetic carbons; that parent company was sold to BASF, and then Group14 was spun out in 2015 to apply that technological approach to silicon anodes.

Such scientific complexity usually harshes the vibes of venture investors hyped up on the prospect of quick software returns. But the prize in this case was particularly alluring. Silicon enthusiasts, Group14 included, claim that adding it to anodes can deliver 50 percent more energy density than today’s batteries. That could materialize as an EV that goes much farther on a single charge, or one that goes the same distance with a smaller, cheaper battery.

Several companies are vying to be the first to scale up the technology. Sila Nanotechnologies has raised several hundred million dollars to that end. Sionic Energy makes a silicon anode and a co-optimized electrolyte. It’s supplying drones first but aims to get its anodes into vehicles by mid-decade.

“We’ll be the first ones in EVs,” Luebbe said. ​“But it’s going to take a lot of actors to transform an industry.”

Luebbe declined to name which car model will be the first to market with silicon anodes. But the Porsche investment did come with a commitment to start making lithium-silicon batteries for its cars in 2024.

“They’re recognized as one of the technology leaders in the automotive industry,” Luebbe said. ​“We’re really excited about that validation from the Porsche team.”