The present application relates to the field of energy storage device production technology, in particular, to a battery comprising a battery body and a flange portion; the battery body includes a first side face protruding from a surface of the battery body; the flange portion is arranged outside the battery body and includes a protrusion segment connected to the battery body, the protrusion segment protruding away from the battery body. The present application ensures the amount of glue at the valley bottom of the side as much as possible, so that the adhesive force here is improved, the tightness of the valley bottom is ensured and the problem of opening the flange portion when transporting, using, or storing is reduced as much as possible.