LITHIUM SECONDARY BATTERY

A lithium secondary battery, including: a positive electrode; a negative electrode; a non-aqueous electrolyte having lithium ion conductivity; and a separator interposed between the positive electrode and the negative electrode. The positive electrode includes a positive electrode mixture layer containing a positive electrode active material, and a positive electrode current collector. The positive electrode active material includes a composite oxide containing lithium and a transition metal. A molar ratio: M/Mof a total lithium amount per unit area Min the positive electrode and the negative electrode to a transition metal amount per unit area Min the positive electrode is 1.1 or less. The negative electrode includes a negative electrode current collector, and a plurality of porous films laminated on the negative electrode current collector and having electrically insulating properties.