Electric storage device

In an embodiment, an energy storage device includes an electrode body, a housing accommodating the electrode body, and a metal external terminal disposed in the housing, the external terminal includes a flange portion expanding along an outer surface of the housing, and a shaft portion extending from the flange portion to penetrate the housing and electrically connected to the electrode body, the flange portion is made of a cladding material, and the shaft portion is made of a metal material. The cladding material has a plurality of metal layers stacked in the direction of penetration of the shaft portion, adjacent metal layers among the plurality of metal layers are made of different types of metal, and a metal layer located at one end in the direction of penetration among the plurality of metal layers in the flange portion is made of the same type of metal as the shaft portion and is welded to the shaft portion. 在本实施方式中，蓄电元件的特征在于，具有：电极体、收容电极体的外壳、配置于外壳的金属制的外部端子，外部端子具有：沿外壳的外表面扩开的凸缘部、从凸缘部延伸从而贯穿外壳且与电极体导通的轴部，凸缘部