SECONDARY BATTERY AND METHOD FOR MANUFACTURING SAME

A method of manufacturing a secondary battery including a joining step of clamping a negative electrode core body stacked part and a negative electrode current collector by a horn and an anvil, and in a state where the anvil is in contact with the negative electrode current collector, ultrasonically joining the negative electrode core body stacked part and the negative electrode current collector to form a joint part; and an oxidation treatment step of oxidizing a portion, in contact with the anvil, of the negative electrode current collector in the joining step.