The positive electrode includes a positive electrode composite layer. The negative electrode includes a negative electrode composite material layer. A whole of the positive electrode composite layer and a portion of the negative electrode composite material layer face each other with the separator being interposed therebetween. The negative electrode composite material layer includes a first region and a second region. The first region is a region that does not face the positive electrode composite layer and that extends from a position facing one end portion of the positive electrode composite layer to a point separated from the position by more than or equal to 0.1 mm and less than or equal to 10 mm. The second region is a region other than the first region. The first region includes silicon oxide doped with lithium. The second region includes silicon oxide.