BATTERY CELL, BATTERY AND ELECTRIC DEVICE

The present application discloses a battery cell, a battery and an electrical device. The battery cell comprises an electrode assembly, a shell, a pressure relief mechanism and a support plate, wherein the shell is used for accommodating the electrode assembly and comprises a first side plate; the pressure relief mechanism is arranged on the first side plate and is configured to be actuated when the internal pressure of the battery cell reaches a first threshold, so as to release the internal pressure; the support plate is arranged between the first side plate and the electrode assembly; the support plate is provided with a weak portion which is opposite to the pressure relief mechanism in the thickness direction of the first side plate; the shape of the weak portion is the same as that of the outline of the pressure relief mechanism, and the external dimension of the weak portion is not greater than the dimension of the outline of the pressure relief mechanism; the support plate is configured to rupture along the weak portion when the internal pressure of the battery cell reaches a second threshold, so as to form a channel for guiding fluid to the pressure relief mechanism. The technical solutions in the embodiments of the present application can effectively improve the safety of battery cells.