Solid electrolyte and fabrication method therefor, and all-solid-state secondary battery and fabrication method therefor

摘要

A solid electrolyte includes a particle having a first portion that includes, as constituent elements, lanthanum (La), lithium, titanium and oxygen, and a second portion that covers a surface of the first portion and includes, as constituent elements, lanthanum, lithium, titanium and oxygen and in which sulfur is coupled to an oxygen deficient portion and at least a surface is oxidized.