BATTERY CELL AND METHOD AND SYSTEM FOR MANUFACTURING SAME, AND BATTERY AND ELECTRIC DEVICE

Embodiments of this application provide a battery cell, a method and system for manufacturing same, a battery, and an electrical device. The battery cell includes: a housing, on which an opening is made; an electrode assembly, accommodated in the housing, where a first tab is disposed on the electrode assembly at an end oriented toward the opening; and an end cap, configured to fit and cover the opening. The end cap includes a cap body and a first protruding portion connected to the cap body. A fragile portion is disposed on the cap body. The end cap is configured to rupture along the fragile portion when an internal pressure of the battery cell reaches a threshold, so as to release the internal pressure. The first protruding portion protrudes from the cap body toward the electrode assembly, and is configured to support the first tab so that an avoidance clearance configured to avoid the fragile portion is formed between the first tab and the cap body. This application reduces the risk that the first tab crushes the fragile portion, and improves the sealing performance and safety performance of the battery cell.