Battery

A battery, comprising an explosion-proof valve and a battery casing, wherein the explosion-proof valve is arranged in the battery casing, the explosion-proof valve comprises a first straight line segment, a second straight line segment and a circular arc segment, and two ends of the circular arc segment are respectively connected to the first straight line segment and the second straight line segment, at least one of the first straight line segment, the second straight line segment and the circular arc segment is able to be broken through, a length of the first straight line segment and a length of the second straight line segment are respectively a and b, and an arc length of the circular arc segment is c, a radius of curvature of the circular arc segment is r, wherein 0.9≤a/b≤1.9 and 0.5≤c/r≤2.7.