Prosser

Correct me if I'm wrong, but isn't the ceramic separator EFL has been using a Solid state battery

"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.[1][2] Materials proposed for use as solid electrolytes in solid-state batteries include ceramics"

https://en.wikipedia.org/wiki/Solid-state_battery