Abstract: Provided is a secondary battery, in the secondary battery, the positive electrode has a covering portion covered with a positive electrode active material layer and a positive electrode active material non-covered portion on a strip-shaped positive electrode foil, a negative electrode has a covering portion covered with a negative electrode active material layer and a first negative electrode active material non-covered portion on a strip-shaped negative electrode foil, the positive electrode active material non-covered portion is joined to the positive electrode current collector plate at one end portion of the electrode winding body, the first negative electrode active material non-covered portion is joined to the negative electrode current collector plate at the other end portion of the electrode winding body, the electrode winding body has flat surface formed by bending one or both of the positive electrode active material non-covered portion and the first negative electrode active material non-covered po

Abstract: A secondary battery including an electrode wound body having a structure in which a positive electrode and a negative electrode are stacked and wound with a separator interposed therebetween, a positive electrode current collector plate, a negative electrode current collector plate, and an exterior can that accommodates the electrode wound body, the positive electrode current collector plate, and the negative electrode current collector plate, wherein the positive electrode has a positive electrode active material non-covered portion on a positive electrode foil, the negative electrode has a negative electrode active material non-covered portion on a negative electrode foil.

Abstract: A lid for a cell tray is provided. The lid includes a cover configured to cover a battery accommodated in the cell tray, and a fire extinguishing liquid. The cover has plate-shaped cover plates with a gap, and the fire extinguishing liquid is configured to be sealed in a package disposed in the gap. The cover plates are configured to have a plurality of opening holes.

Abstract: A lid for a cell tray is provided, The lid includes a cover configured to cover a battery accommodated in the cell tray, and a fire extinguishing liquid. The cover has plate-shaped cover plates with a gap, and the fire extinguishing liquid is configured to be sealed in a package disposed in the gap. The cover plates are configured to have a plurality of opening holes.