Secondary Battery

A secondary battery (100) includes cells (A and B) that include a shaft (110), a battery case (120), a positive electrode sheet (202), a negative electrode sheet (206), a separator sheet (204, 208), and electrolytic solution. An edge portion of the positive electrode sheet (202) in the cell (A) is overlapped and joined with an edge portion of the negative electrode sheet (206) in the adjacent cell (B).