Abstract: A nonaqueous electrolyte secondary battery according to one embodiment of the present disclosure is provided with a wound-type electrode body. A negative electrode has: a negative electrode collector; and negative electrode mixture layers that are formed on both lateral surfaces of the negative electrode collector, while containing at least a negative electrode active material and a binder. The negative electrode mixture layers include an inner negative electrode mixture layer that is positioned on the inner circumference side of the negative electrode collector and an outer negative electrode mixture layer that is positioned on the outer circumference side. The swelling degree of the binder contained in the outer negative electrode mixture layer is higher than the swelling degree of the binder contained in the inner negative electrode mixture layer; and the outer negative electrode mixture layer contains a binder that has a swelling degree of from 150% to 250%.

Abstract: A secondary cell that is one example of this embodiment comprises a winding-type electrode body in which a positive electrode and a negative electrode are wound with a separator interposed therebetween. The positive electrode has: a positive-electrode collector body; a first positive-electrode mixture layer formed on a first surface of the positive-electrode collector body facing the outer side of the electrode body; and a second positive-electrode mixture layer formed on a second surface of the positive-electrode collector body facing the inner side of the electrode body. The first positive-electrode mixture layer includes a first positive-electrode active material, and the second positive-electrode mixture layer includes a second positive-electrode active material, the average surface roughness of the first positive-electrode active material being greater than the average surface roughness of the second positive-electrode active material.

Abstract: The purpose of the present invention is to provide a winding-type nonaqueous electrolyte secondary battery which is capable of minimizing degradation of charge-discharge cycle characteristics.