Abstract: A vehicle has a battery pack. The battery pack includes batteries or a battery module. The battery module includes batteries. Each battery includes a battery casing and an explosion-proof valve. The explosion-proof valve is arranged on the battery casing. The explosion-proof valve is provided with a notch groove. The explosion-proof valve includes an opening area. In the depth direction of the notch groove, the shape of the orthographic projection of the opening area is non-circular. The outer edge of the orthographic projection of the opening area is a preset opening boundary, the area of the orthographic projection of the opening area being S1, the area of the orthographic projection of the explosion-proof valve being S, S1 and S meeting: S1/S?3, and the units of S1 and S both being mm2.

Abstract: A battery, a battery pack, and a vehicle. The battery comprises: a battery casing; a pole core, arranged in the battery casing; and a positive electrode lead-out piece and a negative electrode lead-out piece, the positive electrode lead-out piece comprising a positive-electrode first connecting sheet, the negative electrode lead-out piece comprising a negative-electrode first connecting sheet, and the positive-electrode first connecting sheet and the negative-electrode first connecting sheet being distributed at two opposite ends of the pole core in the length direction of the battery casing. The distance between the positive-electrode first connecting sheet and the negative-electrode first connecting sheet in the length direction of the battery casing is L1, the size of the battery in the length direction of the battery casing is L, and L1 and L meet: 0.95?L1/L?0.99.

Abstract: A cylindrical battery includes a housing having an accommodating space; and a negative electrode sheet, a first separator, a positive electrode sheet, and a second separator that are wound multiple turns forming an electrode core. The housing is co-axial with the electrode core that is disposed in the accommodating space. The positive electrode sheet includes a positive electrode material layer and a positive electrode foil layer. The negative electrode sheet includes a negative electrode material layer and a negative electrode foil layer. Some of the wound turns of the positive electrode foil layer extends toward an end of the housing to form a positive electrode tab. Some of the wound turns of the negative electrode foil layer extends toward another end of the housing to form the negative electrode tab.