Lithium-ion dominates the battery world, but alternative chemistries are finding their niches. I talk with Landon Mossburg, CEO of Peak Energy, about using sodium-ion batteries for large-scale grid storage. They trade some energy density for a longer life and radically lower operating costs, thanks to an innovative, passively cooled design. We also explore the geopolitical opportunity of competing in a battery market that China doesn't already completely own.