| 主权项 |
1. A battery comprising:
a positive electrode, and a negative electrode, wherein,
the positive electrode and the negative electrode are spirally wound to form a wound body,the negative electrode comprises (1) an active material layer having an active material including at least Si or Sn, and (2) a negative electrode current collector having (a) a first principal plane facing outward and corresponding to an outer face of the wound body and (b) a second principal plane facing inward and corresponding to an inner face of the wound body,the first principal plane has a first surface roughness in a range of 0.2 μm to 3.0 μm, both inclusive,the negative electrode current collector has a thickness in a range of 5 μm to 30 μm, both inclusive,a difference between the first surface roughness of the first principal plane of the negative current collector and a second surface roughness of the second principal plane of the negative electrode current collector is greater than 0.05 μm, andeach of the first surface roughness and the second surface roughness is an arithmetic mean surface roughness Ra. |
