Cathode material for lithium secondary battery, lithium secondary battery, and secondary battery module using the battery

Abstract

A cathode material for a lithium secondary battery capable of stably suppressing manganese dissolution even under high temperature and voltage conditions is provided. Further, by using the cathode material for a lithium secondary battery, a lithium secondary battery excellent in a charge/discharge cycle profile at a high temperature and a secondary battery module equipped with the battery are provided. The cathode material for a lithium secondary battery comprises a lithium manganese composite oxide and a coating layer formed on the surface of the lithium manganese composite oxide. The coating layer includes an oxide compound or a fluoride compound each containing M (wherein, M is at least one element selected from the group of Mg, Al and Cu), and a phosphorous compound. An atomic density of M at the side of the lithium manganese composite oxide in the coating layer is higher than an atomic density of M at the side of a surface layer of the coating layer facing to the electrolyte.

Dependencies are inferred from the claim text.