To improve a charging and discharging cycle life and low temperature load characteristics of a battery by reducing the amount of a conductive material added to a positive electrode.

This secondary battery is provided with a negative electrode 1 having sheet-shaped negative electrode collectors 3 and a negative electrode lead 4, and sheet-shaped positive electrode collectors 5 and a positive lead 6, and is formed with a spiral battery element constituted by winding a positive electrode 2 whose positive electrode mixture is produced by means of a carbon master batch method through a separator 7. The battery element is inserted in the bottom part of a battery can 8 through an insulating plate 9. The negative electrode lead 4 is welded to the can bottom of the battery can 8, the positive electrode lead 6 is welded to a safety valve 10, and a battery cover 12 is welded to the battery can 8 through an insulating sealing gasket 11 for constitution.