Non-aqueous electrolyte secondary battery

摘要

Storage performance in a charged state is improved in a non-aqueous electrolyte battery that contains 10 volume % or more of gamma-butyrolactone, which is highly safe and reliable, as a solvent. A non-aqueous electrolyte secondary battery has a positive electrode containing a positive electrode active material composed of a lithium-containing transition metal oxide containing lithium and cobalt, a negative electrode, and a non-aqueous electrolyte solution composed of a solute and a solvent. The solvent contains 10 volume % or more of gamma-butyrolactone with respect to the total solvent, and the positive electrode active material contains a Group IVA element and a Group IIA element of the periodic table.