A battery technology that’s getting a lot of attention is solid-state batteries, lithium-ion batteries that replace the liquid electrolyte with a solid material. Chinese battery manufacturer CATL alone had more than 1,000 people devoted to solid-state battery research as of 2024, and battery manufacturers like BYD , LG , and Samsung are also working on the technology. US and European startups making solid-state batteries have collectively raised over $4 billion as of 2025 .

Solid-state batteries have several potential advantages over the lithium-ion batteries with liquid electrolyte we use now. For one, replacing the liquid electrolyte with a solid should allow for lighter batteries, requiring less mass per unit of energy delivered.…