SECONDARY BATTERY

Provided is a technique increasing the capacity of secondary batteries. According to the technique disclosed herein, there is provided a secondary battery having a flat wound electrode body in which a first electrode and a second electrode different from the first electrode are laminated and wound with a separator interposed therebetween, and a first current collecting member. The wound electrode body has a plurality of first electrode tabs. Ten or more first electrode tabs are provided and stacked. In a thickness direction of the wound electrode body, a ratio (N1A/N1B) of the number N1A of stacked layers of the first electrode tabs and the number N1B of stacked layers of the first electrode satisfies 0.3 to 0.7. The plurality of first electrode tabs are bent and connected to the first electrode current collecting member.