Battery and battery apparatus

A battery, comprising:

• a cover plate, wherein an explosion-proof hole is arranged on the cover plate;
• an explosion-proof valve, wherein the explosion-proof valve is arranged on the cover plate to shield the explosion-proof hole;
• and
• a protective patch, wherein the protective patch is located on an outer side of the cover plate and shields the explosion-proof hole, a 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, the notch is convertible between a closed state under normal conditions and an open state when a predetermined pressure is applied, such that when the notch is in the closed state, the chamber is a sealed chamber, and when the predetermined pressure is applied, the notch is in the open state, and the chamber is an unsealed chamber and communicates with an outside through the notch,
• wherein 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, the protective patch has a tensile strength of c, where c/b=xb−1.073 and 160 (Mpa/mm2)≤x≤175 (Mpa/mm2), and a tensile strength test method applied to the protective patch is:
• GB/T 13542.2−2009,
• wherein a reinforcement ring is arranged on the cover plate, the reinforcement ring is arranged on an outer surface of the cover plate and surrounds the explosion-proof hole, the protective patch is arranged on a surface of the reinforcement ring facing away from the cover plate, and a hole wall of the explosion-proof hole, the explosion-proof valve, and the protective patch together enclose the chamber,
• the battery further comprising an insulating top cover, wherein the insulating top cover is fixedly arranged on the outer surface of the cover plate, a through hole opposite to the explosion-proof hole is arranged on the insulating top cover, and an upper surface of the insulating top cover is flush with an upper surface of the protective patch,
• the reinforcement ring is located in the through hole of the insulating top cover,
• a gap is provided between the reinforcement ring and a hole wall of the through hole, and an interval is formed between the hole wall of the through hole and a circumferential outer edge of the protective patch,
• the notch is a cut formed without material removal such that the notch is normally in the closed state to seal the chamber, and the notch relies on elastic deformation to convert to the open state,
• the notch is located in a center of the protective patch, the notch comprises a first notch segment and a second notch segment, the first notch segment intersects with the second notch segment, and/or a middle portion of the first notch segment intersects with a middle portion of the second notch segment,
• the intersecting first notch segment and the second notch segment form at least one cantilever portion on the protective patch, the protective patch is configured to be connected to an evacuation device, such that when a vacuum degree of a space where the protective patch is located is g, an open angle of the cantilever portion is h, where 1×10−2 Pa≤g≤4.5×10−2 Pa and 5°≤h ≤5020 .