A battery includes a battery cell and a packaging body, an edge of at least one side of the packaging body is provided with a sealing region to seal and wrap the battery cell body in the packaging body, and the packaging body includes a heat sealing layer; and in the sealing region, a side, away from the battery cell body, of the heat sealing layer is an outer sealing side, a side, close to the battery cell body, of the heat sealing layer is an inner sealing side, and a crystallinity of the outer sealing side is greater than a crystallinity of the inner sealing side. The battery includes the packaging body with a high packaging strength and a strong resistance to bending, which may more effectively block water vapor from entering a battery, and also improves safety performance and a service life of a battery.