LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a high voltage and high energy lithium ion secondary battery having a lithium manganese oxide of a spinel structure as a positive electrode that is excellent in charge and discharge capacity and charge and discharge cycle characteristics. SOLUTION: This is a lithium ion secondary battery which comprises a positive electrode that has a positive electrode active material comprising lithium manganese oxide of a spinel structure as expressed in the chemical formula LixMnOy (wherein x is a real number 0.55<=x<=0.65, y is a real number 1.80<=y<=2.20), a negative electrode and a non-aqueous electrolyte containing lithium ion.