Secondary battery

Abstract

A secondary battery is provided and includes a sheet-like positive electrode and a sheet-like negative electrode laminated on the positive electrode with a separator interposed therebetween. The positive electrode and the negative electrode are wound. The negative electrode includes a sheet-like negative electrode current collector, a first negative electrode material layer disposed on an inner surface on an inner side in a lamination direction in the negative electrode current collector, and a second negative electrode material layer disposed on an outer surface on an outer side in the lamination direction in the negative electrode current collector. The first negative electrode material layer is larger than the second negative electrode material layer in terms of an expansion coefficient in a thickness direction of the negative electrode in a charged state with respect to a discharged state.

Dependencies are inferred from the claim text.