BATTERY CELL, BATTERY, AND ELECTRIC DEVICE

A battery cell, a battery, and an electric device. The battery cell comprises: an electrode assembly comprising a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet form a flat region; and a housing comprising a first wall portion and two second wall portions, the two second wall portions being respectively located on two sides of the flat region in a first direction. The first wall portion comprises a shell body and a pressure relief portion, wherein the shell body is arranged around the periphery of the pressure relief portion, a notch groove is formed in the pressure relief portion and has a first groove wall section obliquely extending in the first direction on a bottom wall thereof, and the first groove wall section is at an angle to the first direction.