https://techcrunch.com/2021/02/24/can-solid-state-batteries-power-up-for-the-next-generation-of-evs/

Lithium-ion batteries power almost every new phone, laptop and electric vehicle. But unlike processors or solar panels, which have improved exponentially, lithium-ion batteries have inched along with only incremental gains.

For the last decade, developers of solid state battery systems have promised products that are vastly safer, lighter and more powerful. Those promises largely evaporated into the ether — leaving behind a vapor stream of disappointing products, failed startups and retreating release dates.