EV: solid state batteries

 Hyundai, Kia Announce Solid State Battery With Factorial Energy

"Factorial’s advances are based on FEST (Factorial Electrolyte System Technology), which leverages a proprietary solid electrolyte material that enables safe and reliable cell performance with high-voltage and high-capacity electrodes and has been scaled in 40Ah cells that perform at room temperature.

FEST is safer than conventional lithium-ion technology, extends driving range by 20 to 50 percent, and is drop-in compatible for easy integration into existing lithium-ion battery manufacturing infrastructure."

Solid-state battery - Wikipedia
A solid-state battery is a battery technology that uses solid electrodes and a solid electrolyte, instead of the liquid or polymer gel electrolytes found in lithium-ion or lithium polymer batteries

Solid-State Batteries Rev Up Electric Cars, Boost Grid Storage - IEEE Spectrum

What is a Solid-State Battery for an Electric Car?

BMW and Ford are investing $130 million in Solid Power, a Colorado-based solid-state battery startup. Hyundai is putting $100 million into SolidEnergy Systems, a spin-off company from the Massachusetts Institute of Technology. Toyota, which has partnered with Panasonic, has announced that a prototype SUV featuring solid-state battery performance would debut this year. Also making investments are General Motors and Volkswagen.