A battery includes a conductive piece, an electrode assembly, and a housing including a first wall provided with an opening, a second wall disposed opposite to the first wall along a first direction, and a sidewall. An accommodation cavity accommodating the electrode assembly is formed between the first wall, the second wall, and the sidewall. In the first direction, a projection of the conductive piece is at least partly located in a region of a projection of the opening. The battery further includes a sealing structure disposed at an end of the first wall towards the conductive piece and connected to the first wall and an insulation piece disposed between the sealing structure and the conductive piece. A thermal expansion coefficient of at least one of the sealing structure or the conductive piece is greater than a thermal expansion coefficient of the insulation piece.