| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative electrode capable of absorbing expansion when a negative electrode active material is alloyed, and a secondary battery using the negative electrode, in order to solve such problems that, although materials such as silicon, which are alloyed with lithium, an oxide thereof or the like have a high theoretical capacity density as a negative electrode active material, the volume of these materials is greatly changed due to charging and discharging, so that a negative electrode active material is pulverized and separated from a current collector because of repeated expansion and contraction, or a negative electrode current collector is stretched as a negative electrode active material layer is expanded, leading to wrinkles in the negative electrode current collector.SOLUTION: A plurality of projections and depressions are provided in a negative electrode active material layer 102 and a negative electrode current collector 101. The projections and depressions of the negative electrode active material layer 102 and the negative electrode current collector 101 overlap with each other. The plurality of projections and depressions provided in a negative electrode active material can absorb expansion of the negative electrode active material and suppress deformation thereof. The plurality of projections and depressions provided in the negative electrode current collector 101 can suppress deformation of the negative electrode current collector 101 caused by expansion and contraction of the negative electrode active material.SELECTED DRAWING: Figure 1 |
