One of the great innovations in Li-ion batteries: ceramic interface via ceramic coated separator made the transition of its polymer based separator to ceramic coated (interface) separators during the last a couple of years. Nearly 90% Li-ion batteries in consumer electronics and 2nd generation EDV are using ceramic coated separators today. This ceramic interface via ceramic coated separator greatly enhanced Li-ion energy density (reduced oxidation of separators that enable the use of high voltage cathodes), greatly improved battery safety (reduce the thermal propagation to avoid serious thermal runaway) and battery life (ceramic react with oxidized electrolytes, H2O and HF that continuously purifies the electrolyte). The development, mechanism, specific ceramic interfaces and battery results will be presented and discussed.