A battery cell, comprising: a battery box comprising a first wall and a pressure relief mechanism, wherein the pressure relief mechanism is arranged on the first wall, and the pressure relief mechanism is configured to be actuated to relieve internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a threshold value; a protective member positioned on an outer side of the first wall and comprising a body portion, a shielding portion and a weak portion, wherein the body portion is configured to be connected to the first wall, the shielding portion protrudes outward from the body portion in a direction perpendicular to the first wall and is configured to shield the pressure relief mechanism, the weak portion is configured to connect the body portion to the shielding portion, and the weak portion is configured to be broken when the pressure relief mechanism is actuated, so as to disconnect the body portion from the shielding portion, wherein an outer surface of the first wall is provided with a protrusion, and the shielding portion is positioned on one side, away from the pressure relief mechanism, of the protrusion in the direction perpendicular to the first wall, and wherein a plurality of through open holes are provided between the body portion and the shielding portion, the weak portion comprises a plurality of weak subareas, and the plurality of weak subareas and the plurality of open holes are alternately provided on a periphery of the shielding portion; and a protective film arranged on a surface, facing the shielding portion, of the protrusion and covering the pressure relief mechanism. a battery box comprising a first wall and a pressure relief mechanism, wherein the pressure relief mechanism is arranged on the first wall, and the pressure relief mechanism is configured to be actuated to relieve internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a threshold value; a protective member positioned on an outer side of the first wall and comprising a body portion, a shielding portion and a weak portion, wherein the body portion is configured to be connected to the first wall, the shielding portion protrudes outward from the body portion in a direction perpendicular to the first wall and is configured to shield the pressure relief mechanism, the weak portion is configured to connect the body portion to the shielding portion, and the weak portion is configured to be broken when the pressure relief mechanism is actuated, so as to disconnect the body portion from the shielding portion, wherein an outer surface of the first wall is provided with a protrusion, and the shielding portion is positioned on one side, away from the pressure relief mechanism, of the protrusion in the direction perpendicular to the first wall, and wherein a plurality of through open holes are provided between the body portion and the shielding portion, the weak portion comprises a plurality of weak subareas, and the plurality of weak subareas and the plurality of open holes are alternately provided on a periphery of the shielding portion; and a protective film arranged on a surface, facing the shielding portion, of the protrusion and covering the pressure relief mechanism.