NONAQUEOUS ELECTROLYTE SECONDARY BATTERY - HITACHI MAXELL ENERGY LTD

Title:

NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

Document Type and Number:

Japanese Patent JP2013020975

Kind Code:

A

Abstract:

To provide a nonaqueous electrolyte secondary battery excellently achieving both a high capacity and a high level of safety.

The nonaqueous electrolyte secondary battery comprises a positive electrode comprising a positive electrode mixture layer which contains an active material containing a layered lithium-manganese-nickel-cobalt complex oxide containing at least Mn, Ni, and Co, and having a specific surface area of 0.1 to 0.6 m²/g, and a spinel-type lithium-manganese complex oxide having a specific surface area of 0.05 to 0.3 m²/g. In the positive electrode mixture layer, the percentage of the spinel-type lithium-manganese complex oxide with respect to the total mass of the layered lithium-manganese-nickel-cobalt complex oxide and the spinel-type lithium-manganese complex oxide is in the range of 30 to 50 mass%, and the molar ratio of Li/Mn is in the range of 0.35 to 0.53. The density of the positive electrode mixture layer is in the range of 3.0 to 3.6 g/cm³, and the positive electrode mixture layer contains at least acetylene black as a conductive assistant.