Energy storage element

Abstract

An embodiment of the present invention is provided with an electrode assembly, a case in which the electrode assembly is housed, and a metal external terminal disposed on the case. The external terminal comprises a flange portion extending along the case on the outside of the case, and a shaft portion which extends from the flange portion, penetrates through the case, and is in electrical communication with the electrode assembly. The flange portion includes a plurality of metal layers stacked in a penetrating direction of the shaft portion. The embodiment is characterized in that at least one of the plurality of metal layers covers a peripheral end surface of another metal layer.