POSITIVE ELECTRODE, LITHIUM-ION SECONDARY BATTERY, AND METHOD OF PRODUCING POSITIVE ELECTRODE

A positive electrode includes at least a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is formed on a surface of the positive electrode current collector. The positive electrode current collector includes an aluminum foil and a porous film. The porous film covers a surface of the aluminum foil. The porous film contains at least aluminum oxide. The porous film has a thickness not smaller than 10 nm and not greater than 800 nm. The porous film has a dynamic hardness not lower than 5 and not higher than 200.