Patent ID: 8232008
Filing Date: 2012-07-31
Classification: H01M,Y02E,Y02P

Abstract:
1. A secondary battery comprising: an electrode body formed by superimposing a positive electrode including a belt-shaped positive electrode current collector, a positive electrode active material layer formed on a surface of the positive electrode current collector, a plurality of positive electrode tabs protruding from one side edge of the positive electrode current collector in a longitudinal direction thereof, and formed integral with the positive electrode current collector; and a negative electrode including a belt-shaped negative electrode current collector, negative electrode active material layer formed on a surface of the negative electrode current collector, a plurality of negative electrode tabs each protruding from one side edge of the negative electrode current collector in a longitudinal direction thereof, and formed integral with the negative electrode current collector; upon each other with a belt-shaped separator interposed between the electrodes, and rolling up the positive and negative electrodes and the separator into a spiral shape, at least one side edge of the positive electrode current collector in the longitudinal direction thereof including a plurality of step parts discontinuously formed in the longitudinal direction at unequal intervals, and extending at both sides of each step part with a deviation of 0.2 mm or more, and 1 mm or less, and at least one side edge of the negative electrode current collector in the longitudinal direction thereof including a plurality of step parts discontinuously formed in the longitudinal direction at unequal intervals, and extending on both sides of each step part with a deviation of 0.2 mm or more, and 1 mm or less.