BATTERY AND BATTERY APPARATUS

A battery and a battery apparatus are provided. The battery includes a cover plate, an explosion-proof valve arranged on the cover plate, and a protective patch 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 to form at least one cantilever portion. When a predetermined pressure is applied, the sealed chamber communicates with an outside through the cantilever portion that is opened. The cantilever portion has an area of a mm. The protective patch has a thickness of b mm, where 0.5 mm≤a/b≤20 mm and 0.01 mm≤b≤1.2 mm, and the protective patch has a wetting tension of c, where 20 N/m≤c≤70 N/m.