NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, METHOD OF MANUFACTURING NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, AND METHOD OF USING NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

A nonaqueous electrolyte secondary battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte, the positive electrode containing, as a positive active material, a lithium transition metal composite oxide having an α-NaFeOtype crystal structure, a molar ratio of Li to Me, Li/Me of more than 1, Me representing transition metal elements including Ni and Mn or including Ni, Mn, and Co, and a molar ratio of Mn to Me, Mn/Me of 0.40 or more and 0.65 or less, and the nonaqueous electrolyte containing, as an electrolyte salt, LiPFand a lithium imide salt.