An adhesive film for a metal terminal is interposed between a metal terminal electrically connected to an electrode of a power storage device element, and a power storage device exterior material that seals the power storage device element, the adhesive film comprising a laminated body including, in the following order: a first polyolefin layer disposed on the metal terminal side; a base material; and a second polyolefin layer disposed on the power storage device exterior material side, wherein the adhesive film has a Martens hardness of at most 30 N/mm.sup.2 as measured in a direction perpendicular to a cross-section in the thickness direction of the first polyolefin layer.

An energy storage apparatus includes: an energy storage device; a substrate in which a through hole penetrating a main surface is formed; a through member that penetrates the through hole; and a lateral member disposed lateral to the substrate and covering a side surface of the substrate. The lateral member includes an opening through which at least one of two portions of the through member, the two portions sandwiching the through hole, is visually recognizable from the outside.

An adhesive film for metal terminals is interposed between a metal terminal connected to an electrode of a power storage device element and a power storage device external member, and includes, a first polyolefin layer, a substrate, and a second polyolefin layer disposed on the metal terminal side. A sea-island structure is observed in a sectional image of the first polyolefin layer in a direction parallel to TD, the sectional image being obtained in the range of up to 30% of the thickness of the first polyolefin layer. In the sectional image, after the adhesive film for metal terminals is left to stand for 12 seconds in a heated and pressurized environment in which the temperature is 190° C. and the surface pressure is 0.016 MPa, and then left for one hour at 25° C., the of the total area of the island portions of the sea-island structure is 25.0% to 35.0%.

A power storage device includes: an electrode assembly including a positive-electrode plate, a negative-electrode plate, and a separator which are stacked on one another, the separator being disposed between the positive-electrode plate and the negative-electrode plate; an exterior can accommodating the electrode assembly and an electrolyte solution therein, the exterior can having a side wall with a tubular shape and an opening provided at least at one end of the side wall; a sealing plate closing the opening of the exterior can; and a holding member including one or more facing parts accommodated in the exterior can, each facing part facing the side wall in a first direction and projecting toward the side wall.

A packaging material for a power storage device, comprising at least: a substrate layer; a metallic foil layer with an anti-corrosion treatment layer being disposed on one face or both faces thereof; and a sealant layer in this order, wherein the sealant layer includes a polypropylene-based resin (A) and 1 to 40% by mass of incompatible component (B), and maximum seal strength S.sub.M in an adhered portion resulting from adhesion by heat-sealing the packaging material is 35 N/15 mm or more, and in addition, the packaging material for a power storage device satisfies the following requirements (1) or (2): (1) a ratio S.sub.S/S.sub.M of seal strength S.sub.S to maximum seal strength S.sub.M in a stable range is 0.3 or more; (2) a ratio S.sub.A/S.sub.M of average seal strength S.sub.A to maximum seal strength S.sub.M is 0.3 or more.

An electrode assembly for an ultracapacitor is provided. The electrode assembly contains a first electrode comprising a first current collector electrically coupled to a first carbonaceous coating, a second electrode comprising a second current collector electrically coupled to a second carbonaceous coating, and a separator positioned between the first electrode and the second electrode. At least a portion of the first current collector projects beyond the first longitudinal edge to define a first projecting portion, wherein the offset ratio of the first projecting portion is from about 0.02 to about 0.3.

A terminal structure to be adopted for a power storage device including an outer case that has an opening, includes: a sealing plate sealing the opening; a terminal member inserted into a terminal hole formed in the sealing plate and electrically connected to an electrode; and a first insulating member arranged between the sealing plate and the terminal member, and arranged on an outer surface side of the sealing plate facing an outer side of the power storage device. The terminal member has a first extended part extending further outward than an outer periphery of the terminal hole on the outer side of the power storage device. A first protruding part or a second recessed part provided to the first insulating member and a first recessed part or a second protruding part provided to the sealing plate or to the first extended part fit with each other.

An energy storage apparatus includes an energy storage unit including an energy storage device, the energy storage apparatus including a substrate unit including a substrate electrically connected to the energy storage unit and a substrate accommodating unit accommodating the substrate, the substrate unit being attached to the energy storage unit. The substrate accommodating unit includes a gripping unit to grip the energy storage apparatus.

An energy storage apparatus includes an energy storage unit including an energy storage device, the energy storage apparatus including a substrate unit including a substrate electrically connected to the energy storage unit and a substrate accommodating unit accommodating the substrate, the substrate unit being attached to the energy storage unit. The substrate accommodating unit includes a gripping unit to grip the energy storage apparatus.

An energy storage apparatus includes an energy storage unit including a plurality of energy storage devices, a first power cable connected to one of a positive electrode connection terminal of the energy storage unit and a negative electrode connection terminal of the energy storage unit and extending from an end portion of the energy storage unit to an outside of the energy storage unit, and a second power cable connected to the other of the positive electrode connection terminal and the negative electrode connection terminal and extending from the end portion of the energy storage unit to the outside of the energy storage unit. The first power cable includes a first connector. The second power cable includes a second connector including a structure which allows direct connection to the first connector. The first power cable is placed in a posture which inhibits connection between the first connector and the second connector.