BATTERY CELL AND MANUFACTURING METHOD AND SYSTEM THEREFOR, BATTERY AND ELECTRIC APPARATUS

Provided in the embodiments of the present application are a battery cell and a manufacturing method and system therefor, a battery, and an electrical apparatus. The battery cell comprises: a battery case, comprising a first wall and a pressure-release mechanism, the pressure-release mechanism being arranged on the first wall, and the pressure-release mechanism being used for actuating when the internal pressure or temperature of the battery cell reaches a threshold value in order to release the internal pressure; and a protective component positioned on the outside of the first wall, the protective component comprising a main body part, a shielding part, and a weakened part, the main body part being used for connecting the first wall, the shielding part being used for shielding the pressure-release mechanism, and the weakened part being used for connecting the main body part and the shielding part, the weakened part being configured to rupture when the pressure-release mechanism actuates in order to break the connection between the main body part and the shielding part. The shielding part can block discharged matter released by other battery cells, reducing the risk of the pressure-release mechanism being melted and penetrated by the discharged matter. When thermal runaway occurs in the battery cell, the weakened part ruptures under the action of a high-temperature high-pressure substance so that the high-temperature high-pressure substance is promptly discharged.