Power storage device

A power storage device including an electrode foil that includes a first current collecting foil where a first active material layer is provided on a first surface and a second current collecting foil where a second active material layer is provided on a second surface, and in which a third surface opposite to the first surface of the first current collecting foil and a fourth surface opposite to the second surface of the second current collecting foil are connected to face each other, the power storage device comprising:

• a first metal layer provided at a portion of the first surface of the first current collecting foil where the first active material layer is not provided;
• and
• a second metal layer provided at a portion of the second surface of the second current collecting foil where the second active material layer is not provided, wherein
• the first metal layer and the second metal layer are disposed at positions where the first metal layer and the second metal layer overlap each other in a thickness direction of the electrode foil,
• a thermal expansion coefficient of the first current collecting foil is greater than a thermal expansion coefficient of the second current collecting foil, and
• a thermal expansion coefficient of the first metal layer is smaller than a thermal expansion coefficient of the second metal layer.