BATTERY CELL, BATTERY, AND ELECTRICAL DEVICE

Provided are 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; 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.