BATTERY AND BATTERY APPARATUS

A battery and a battery apparatus are provided. The battery pack includes a cover plate, an explosion-proof valve, and a protective patch. The explosion-proof valve is arranged on the cover plate. The protective patch is arranged on an outer side of the cover plate. A sealed chamber is formed between the explosion-proof valve and the protective patch, and a notch penetrating through the protective patch is arranged on the protective patch in a thickness direction, such that when a predetermined pressure is applied, the sealed chamber communicates with an outside through the notch. The notch has a total length of a and the protective patch has a thickness of b, where 5≤a/b≤100 and 0.01 mm≤b≤1.2 mm, and the protective patch has a tensile strength of c, where c/b=xb.