ELECTRODE ACTIVE SUBSTANCE, METHOD FOR PRODUCING ELECTRODE ACTIVE SUBSTANCE, AND ALL-SOLID BATTERY USING ELECTRODE ACTIVE SUBSTANCE

A negative electrode active substance is used for a negative electrode layer of an all-solid battery and contains a plurality of secondary particles. The plurality of secondary particles contain impregnated particles which are secondary particles having a polymer solid electrolyte region impregnated with the polymer solid electrolyte therein and an active material region.