LITHIUM-IRON-PHOSPHORUS-SULFUR-CARBON COMPOSITE BODY AND METHOD FOR PRODUCING SAME

摘要

A composite body which contains, as constituent elements, phosphorus, lithium, iron, sulfur and carbon, while containing 90% by mole or more of lithium sulfide (Li2S) and having a crystallite size of 80 nm or less as calculated from the half width of a diffraction peak assigned to the (111) plane of Li2S as obtained by powder X-ray diffraction measurement. This composite body has high capacity (especially, high discharge capacity) that is useful for an electrode active material for lithium ion secondary batteries (especially, for a positive electrode active material for lithium ion secondary batteries) without being subjected to a staged preliminary charging/discharging.