POSITIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, POSITIVE ELECTRODE MEMBER, LITHIUM ION SECONDARY BATTERY, AND PRODUCTION METHOD FOR SAID POSITIVE ELECTRODE MATERIAL

摘要

Provided is a cathode material for a lithium ion secondary battery that includes a composite grain formed of lithium iron silicate crystals or lithium manganese silicate crystals and a carbon material. The composite grain has a sea-islands structure in which the lithium iron silicate crystals or lithium manganese silicate crystals are scattered like islands in the carbon material, and the islands have an average value of circle-equivalent diameter of smaller than 15 nm.