An adhesive film for a metal terminal, interposed between a metal terminal electrically connected to an electrode of a power storage device element and a power storage device packaging material for sealing the power storage device element, wherein the adhesive film for a metal terminal includes a laminate sequentially including a first polyolefin layer on the metal terminal side, a base material, and a second polyolefin layer on the power storage device packaging material side, the laminate has a first adhesive layer between the first polyolefin layer and the base material, a second adhesive layer between the second polyolefin layer and the base material, or both the first adhesive layer and the second adhesive layer, the base material has a melting peak temperature of 135° C. or more, and at least one of the first adhesive layer and the second adhesive layer has a melting peak temperature of 100° C. or less.

An adhesive film for metal terminals, which is capable of achieving high sealing performance between itself and a thermally fusible resin layer of an outer covering material in a short time, is interposed between a metal terminal that is electrically connected to an electrode of an electricity storage device element and an outer covering material for electricity storage devices. This adhesive film is configured from a multilayer body provided with: a first polyolefin layer; a base material; and a second polyolefin layer. The heat of fusion ΔH1 of the first polyolefin layer and the heat of fusion ΔH2 of the second polyolefin layer as determined in accordance with JIS K 7122 (2012) satisfy the relational expression ΔH1>ΔH2; and the heat of fusion ΔH3 of the base material as determined in accordance with JIS K 7122 (2012) is 70 J/g or more.

An electricity storage module includes: an electricity storage device; a case that houses the electricity storage device and includes a bottom surface part and the opening part located at a side opposite to the bottom surface part; a lid that covers an opening part; and a sealing member that seals between the case and the lid. The case has a first case surface that surrounds the opening part along an outer periphery of the opening part. The lid has a first lid surface facing the first case surface. The sealing member is disposed between the first case surface and the first lid surface.

An electricity storage module includes: an electricity storage device; a case that houses the electricity storage device and includes a bottom surface part and the opening part located at a side opposite to the bottom surface part; a lid that covers an opening part; and a sealing member that seals between the case and the lid. The case has a first case surface that surrounds the opening part along an outer periphery of the opening part. The lid has a first lid surface facing the first case surface. The sealing member is disposed between the first case surface and the first lid surface.

An energy storage device includes: a casing 30 having an opening; an energy storage element 20 housed in the casing 30; a lid plate 40 mounted in the opening of the casing 30; a positive electrode terminal member 100 and a negative electrode terminal member 71 integrally fixed to the lid plate 40 in an insulation state by an insulating synthetic resin; a positive electrode current collector 60P configured to electrically connect the energy storage element 20 and the positive electrode terminal member 100 to each other; and a negative electrode current collector 60N configured to electrically connect the energy storage element 20 and the negative electrode terminal member 71 to each other, wherein an easy-to-break portion 65 is formed on at least either one of the positive electrode terminal member 100 or the positive electrode current collector 60P.

An electric energy storage device has an inner terminal disposed in a cylindrical metal case and connected to an electrode of a bare cell, wherein the inner terminal includes a plate-shaped terminal body having a circular outer circumference; at least one electrolyte impregnation hole formed through the terminal body in a thickness direction; a flange located at the outer circumference of the terminal body and extending perpendicular to a plane of the terminal body; and a spacer formed to protrude at a periphery of at least one impregnation hole among the impregnation holes or formed by protruding a part of the plane of the terminal body.

An external terminal for an electric energy storage device, which is coupled to an upper end of a cylindrical metal case to cap the metal case and has a hollow formed at a center thereof so that a safety valve is installed therein, wherein the metal case includes an outer part exposed to the outside in an erect state in a normal direction and an inner part positioned below the outer part, and wherein the inner part includes a first surface adjacent to the hollow and a second surface stepped higher than the first surface (112a) toward the outer part (111).

An electric double-layer capacitor that includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes a positive-electrode collector electrode and a positive-electrode polarizable electrode on the positive-electrode collector electrode. The negative electrode includes a negative-electrode collector electrode and a negative-electrode polarizable electrode on the negative-electrode collector electrode. The negative electrode faces the positive electrode. The electrolyte is interposed between the positive electrode and the negative electrode. A separator is provided between the positive-electrode polarizable electrode and the negative-electrode polarizable electrode adjacent to each other. No polarizable electrode is provided on an outer surface of the collector electrode of each one of the positive electrode and the negative electrode positioned outermost in a thickness direction of the electric double-layer capacitor.

An electric double-layer capacitor that includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes a positive-electrode collector electrode and a positive-electrode polarizable electrode on the positive-electrode collector electrode. The negative electrode includes a negative-electrode collector electrode and a negative-electrode polarizable electrode on the negative-electrode collector electrode. The negative electrode faces the positive electrode. The electrolyte is interposed between the positive electrode and the negative electrode. A separator is provided between the positive-electrode polarizable electrode and the negative-electrode polarizable electrode adjacent to each other. No polarizable electrode is provided on an outer surface of the collector electrode of each one of the positive electrode and the negative electrode positioned outermost in a thickness direction of the electric double-layer capacitor.

A package electric double-layer capacitor having a first terminal that extends from a package at a first corner of a first cell, which is adjacent to a second cell, on one side in a second direction orthogonal to a first direction. A second terminal extends from the package at the first corner in the first direction and on a side of the first terminal opposite to the second cell. A third terminal extends from the package at a second corner of the second cell, which is adjacent to the first cell and the first corner. A fourth terminal extends from the package at the second corner in the first direction and on a side of the third terminal opposite to the first cell.