In a capacitor using a capacitor element having an anode foil and a cathode foil wound with a separator interposed between the anode foil and the cathode foil, the separator includes a low insulation part having a low insulation function between the anode foil and the cathode foil, and the low insulation part may be included within a range of 90% in a central portion in a height direction of the capacitor element and within a range of 5 to 90% in a diametrical direction from the center of the capacitor element.

Disclosed is a power storage element including a positive electrode current collector layer and a negative electrode current collector layer which are arranged on the same plane and can be formed through a simple process. The power storage element further includes a positive electrode active material layer on the positive electrode current collector layer; a negative electrode active material layer on the negative electrode current collector layer; and a solid electrolyte layer in contact with at least the positive electrode active material layer and the negative electrode active material layer. The positive electrode active material layer and the negative electrode active material layer are formed by oxidation treatment.

An inspection device (20) for inspecting a structure body (10) including a pair of electrodes and a separator disposed between the pair of electrodes is provided, the inspection device (20) includes: a measurement unit (30) including a direct-current constant voltage generator (32) that generates a constant inspection voltage applied to the pair of electrodes, and a detection circuit (34) that detects a current value between the pair of electrodes resulting from the application of the inspection voltage; and a processing unit (50) that determines whether the structure body (10) is defective or non-defective based on the detected current value, and the processing unit (50) has a function that, if two or more points at which a ratio (ΔI/Δt) of a current value variation amount (ΔI) to a time variation amount (Δt) varies from a value of no less than 0 to a negative value are observed or no point at which the ratio (ΔI/Δt) varies from a value of no less than 0 to a negative value is observed during a period of time immediately after the application of the inspection voltage until the current value becomes constant, determines the structure body (10) as a defective product, and an auxiliary function that obtains a peak current value I.sub.peak, a peak current appearing time t.sub.peak and a current area S.sub.I of a current waveform representing variation in current value I over passage of time t, and if any one of the peak current value I.sub.peak, the peak current appearing time t.sub.peak and the current area S.sub.I deviates from a preset threshold value including an upper limit value and a lower limit value, determines the structure body as a defective product.

An energy storage device includes: an external terminal having any one of positive and negative polarities and including a protrusion and a first terminal; a case having a polarity opposite to the external terminal and including an extension; a substrate disposed to surround an outer circumference of the protrusion of the external terminal through a hole formed at a center thereof; and a connection member located at an upper surface of the substrate and coupled to the first terminal of the external terminal, wherein the first terminal and the substrate are connected by means of the connection member, and the extension is connected to the substrate. Since positive and negative electrodes of the energy storage device are electrically connected to a substrate having a cell balancing function without a harness or any other member, it is possible to improve the economic feasibility and productivity of the energy storage device module.

An object of the present invention is to provide an aluminum plate which is excellent in terms of both step suitability and working characteristics and a collector for a storage device using the same. The aluminum plate of the present invention is an aluminum plate having a plurality of through-holes formed in a thickness direction, in which a thickness of the aluminum plate is 40 μm or less, an average opening diameter of the through-holes is 0.1 to 100 μm, an average opening ratio by the through-holes is 2% to 30%, a content of Fe is 0.03% by mass or more, and a ratio of the content of Fe to a content of Si is 1.0 or more.

An energy storage device includes: an electrode assembly; a positive electrode current collector and a negative electrode current collector connected to the electrode assembly; and a container configured to house the electrode assembly and the positive electrode current collector and the negative electrode current collector, wherein the container has recessed portions, a connecting portion of the positive electrode current collector and a connecting portion of the negative electrode current collector respectively connected to the electrode assembly are housed in the recessed portions, respectively, the electrode assembly has a tab portion which includes a connecting portion connected to the positive electrode current collector and a tab portion which includes a connecting portion connected to the negative electrode current collector, and the tab portions have a bent portion respectively.

An electrical double layer capacitor having electrolyte-containing layer between a first polarizable electrode layer and a second polarizable electrode layer. An insulating adhesive portion adheres to a first current collector and a second current collector which at least partially face each other with the electrolyte-containing layer interposed therebetween. The insulating adhesive portion 15 extends around the first and second polarizable electrode layers and the electrolyte-containing layer. A thickness of the electrolyte-containing layer is larger than a difference between a thickness of the insulating adhesive portion and thicknesses of the first and second polarizable electrode layers.

A laminated power storage device that includes a first end portion of a first current collector extends to an inside of an insulating adhesive portion relative to a first polarizable electrode layer, and a second end portion of a second current collector extends to an inside of the insulating adhesive portion relative to a second polarizable electrode layer.

A supercapacitor contains the zwitterionic polymer hydrogel electrolyte. A change rate of a capacitance retention of the supercapacitor, relative to a specific area capacity at 25° C. is less than 25% at extreme temperature. When temperature is increased to 60° C. or reduced to −30° C. the specific area capacity is changed to 178 mF cm.sup.−2 and 134 mF cm.sup.−2, which are 104% and 78% of that at 25° C. indicating an excellent electrochemical property at the extreme temperature.

A method for fabricating an electrode includes: determining a thickness of an active layer; selecting lithium (Li) foil having a specified thickness; determining widths of one or more Li strips based on an active layer to Li layer weight ratio or volume ratio; laminating the active layer onto a conductive substrate; forming one or more grooves in the active layer exposing a bare surface of the conductive substrate; and pressing the one or more Li strips into the one or more grooves, wherein widths of the one or more grooves are slightly larger than the widths of the Li strips.