There's a little more background in https://cnevpost.com/2025/02/15/byd-demonstration-use-all-solid-state-batteries-2027/ https://cnevpost.com/2025/02/15/byd-de

There's a little more background in https://cnevpost.com/2025/02/15/byd-demonstration-use-all-solid-state-batteries-2027/ https://cnevpost.com/2025/02/15/byd-demonstration-use-all-so... In April 2024, CATL said the were working on prototypes and made some by Nov. They were saying conventional batteries topped out at 350 Wh/kg while solid state could potentially go to 500+ BYD's tech is similar based on sulfide electrolytes. They still seem to have problems with cost and making them in volume.