Pressure relief apparatus, battery cell, battery, and power consuming device

A pressure relief apparatus, comprising:

• a pressure relief portion provided with a first surface and a second surface arranged opposite to each other in a thickness direction of the pressure relief portion;
• and
• at least one stage of depressed groove and an indented groove, the at least one stage of depressed groove and the indented groove being formed in the pressure relief portion in sequence in a direction from the first surface to the second surface,
• wherein:
• a groove bottom wall of the stage of depressed groove farthest away from the first surface among the at least one stage of depressed groove is provided with an opening area, the indented groove is formed along an edge of the opening area, and the opening area is configured to be openable with the stage of indented groove farthest away from the first surface as a boundary;
• the indented groove comprises a first groove segment, a second groove segment, and a third groove segment, the first groove segment and the second groove segment being arranged opposite to each other, the first groove segment and the second groove segment both intersecting with the third groove segment, and the first groove segment, the second groove segment, and the third groove segment being arranged along the edge of the opening area;
• and
• the pressure relief portion is provided with a fourth groove segment, the fourth groove segment being located between the first groove segment and the second groove segment and intersecting with the third groove segment, and two end of the fourth groove segment being not connected to the first groove segment, the second groove segment, and the third groove segment.