Ecellix

Ecellix makes a silicon-carbon anode material with 95% silicon content, synthesized from commodity precursors in a two-step process. Silicon holds around ten times the lithium that graphite does, which is why replacing graphite anodes has been the field's standing goal for over a decade and why billions have been spent chasing it. Silicon also swells past 300% when it takes up lithium, cracking itself apart and destroying the cell's capacity.

The approaches that manage that swelling generally rely on exotic precursors and elaborate nano-engineering, which work in a lab and price themselves out of a factory. Ecellix's argument is cheap inputs and a simple process, which is what determines whether an anode material ever leaves the lab. More energy in the same cell means smaller packs, longer range, and less mined material per kilowatt-hour. The anode is the oldest open problem in lithium batteries.