A battery cell, comprising a pressure relief apparatus, wherein the pressure relief apparatus comprises a pressure relief body and a plurality of score grooves, wherein the pressure relief body comprises a pressure relief portion, the pressure relief portion having a first surface and a second surface (251 1b) opposite to each other in a thickness direction thereof; an accommodating space is formed inside the pressure relief body, the pressure relief body has a plurality of walls defining the accommodating space, the accommodating space is configured for accommodating an electrode assembly, and one wall of the plurality of walls is provided with the pressure relief portion; the plurality of walls comprise a peripheral wall and a bottom wall, the peripheral wall is arranged around an edge of the bottom wall, the peripheral wall and the bottom wall together define the accommodating space, and the bottom wall is provided with the pressure relief portion; the first surface is an outer surface of the bottom wall; the plurality of score grooves are sequentially arranged at the pressure relief portion in a direction from the first surface to the second surface, wherein in two adjacent score grooves in the thickness direction, a maximum width of a score groove farther away from the first surface is less than a minimum width of a score groove closer to the first surface; the plurality of score grooves comprise a first score groove and a second score groove extending in the same direction, and the first score groove is arranged on a bottom surface of the second score groove; the plurality of score grooves further comprise a third score groove, the third score groove is arranged on the first surface, the second score groove is arranged on a bottom surface of the third score groove, and the bottom surface of the third score groove is provided with a plurality of the second score grooves; the plurality of the second score grooves comprise a first groove section, a second groove section, and a third groove section, the first groove section and the second groove section are arranged at an interval, and both the first groove section and the second groove section intersect with the third groove section; and the pressure relief portion comprises an opening region jointly defined by the first groove section, the second groove section, and the third groove section, and the opening region is configured to open with the first groove section, the second groove section, and the third groove section as boundaries; characterized in that the plurality of the second score grooves further comprise a fourth groove section, and in an extension direction of the third groove section, the fourth groove section is located between the first groove section and the second groove section, and the fourth groove section intersects with the third groove section. the pressure relief apparatus comprises a pressure relief body and a plurality of score grooves, wherein the pressure relief body comprises a pressure relief portion, the pressure relief portion having a first surface and a second surface (251 1b) opposite to each other in a thickness direction thereof; an accommodating space is formed inside the pressure relief body, the pressure relief body has a plurality of walls defining the accommodating space, the accommodating space is configured for accommodating an electrode assembly, and one wall of the plurality of walls is provided with the pressure relief portion; the plurality of walls comprise a peripheral wall and a bottom wall, the peripheral wall is arranged around an edge of the bottom wall, the peripheral wall and the bottom wall together define the accommodating space, and the bottom wall is provided with the pressure relief portion; the first surface is an outer surface of the bottom wall; the plurality of score grooves are sequentially arranged at the pressure relief portion in a direction from the first surface to the second surface, wherein in two adjacent score grooves in the thickness direction, a maximum width of a score groove farther away from the first surface is less than a minimum width of a score groove closer to the first surface; the plurality of score grooves comprise a first score groove and a second score groove extending in the same direction, and the first score groove is arranged on a bottom surface of the second score groove; the plurality of score grooves further comprise a third score groove, the third score groove is arranged on the first surface, the second score groove is arranged on a bottom surface of the third score groove, and the bottom surface of the third score groove is provided with a plurality of the second score grooves; the plurality of the second score grooves comprise a first groove section, a second groove section, and a third groove section, the first groove section and the second groove section are arranged at an interval, and both the first groove section and the second groove section intersect with the third groove section; and the pressure relief portion comprises an opening region jointly defined by the first groove section, the second groove section, and the third groove section, and the opening region is configured to open with the first groove section, the second groove section, and the third groove section as boundaries; characterized in that the plurality of the second score grooves further comprise a fourth groove section, and in an extension direction of the third groove section, the fourth groove section is located between the first groove section and the second groove section, and the fourth groove section intersects with the third groove section.