BATTERY

A battery includes a battery casing and an explosion-proof valve. The battery casing includes a first casing member and a second casing member, and the first casing member and the second casing member are welded to form a welded connection region between the first casing member and the second casing member. The welded connection region includes a first region, a second region, and a corner region, and two ends of the corner region are respectively connected to the first region and the second region. The explosion-proof valve is disposed at a corner position of a surface of the first casing member and adjacent to the welded connection region.