Abstract: A capacitor device of the present invention includes a substrate, a float electrode formed on the substrate, a valve metal film formed on the float electrode, a dielectric film formed on the valve metal film by applying an anodic oxidation to a part of the valve metal film, and a pair of electrodes provided in areas overlapping with two different parts of the float electrode on the dielectric film respectively.

Abstract: A capacitor having a cylindrical shape or configuration so that it is capable of being inserted directly into the vasculature of a patient is described. A typical diameter for the present capacitor is about 6 mm. A capacitor of this size would occupy about 9% of the total cross-sectional area of the inferior vena cava prior to the crossover to the heart, where the typical diameter of the vein is about 20 mm. The crossover section has a diameter of about 11 mm to about 12 mm.

Abstract: In an electrode drying process in which the electrode is molded in a sheet shape by kneading activated carbon powder, a binding material and an organic solvent for lubrication and a polarizing property electrode is formed by heating and removing the organic solvent for lubrication in the molded electrode, the organic solvent for lubrication included in the electrode is removed in a state in which the above electrode is widened in the sheet shape. In a manufacturing method of an electrode sheet for the electrical double layer capacitor, continuous drying and vacuum drying are performed in a drying process.

Abstract: An electric double layer capacitor has high static capacitance, and superior durability, and the amount of gas generated by dissociating solvent can be reduced. In an electric double layer capacitor including an anode and a cathode containing active carbon, a separator, and nonaqueous electrolyte solution, the crystallite thickness Lc(002) of the d002 plane of the active carbon used for the anode is set to be larger than the crystallite thickness Lc(002) of the d002 plane of the active carbon used for the cathode.

Abstract: A polarizing electrode for an electric double layer capacitor has good moldability and can achieving higher density of electrode and higher capacity, and an electric double layer capacitor employs the same. The electric double layer capacitor is made of an activated carbon obtained by activating a hard-to-graphitize material (for example, phenol resin) with water vapor, and the activated carbon has a median particle size within a range from 4 ?m to 8 ?m in the particle size distribution and at least a peak observed on the side of smaller particle size than the median particle size in the particle size distribution.

Abstract: This invention provides novel capacitors comprising nanofiber enhanced surface area substrates and structures comprising such capacitors, as well as methods and uses for such capacitors.

Abstract: The present invention provides a secondary battery and a capacitor which may provide an excellent high rate and cycle characteristic as well as sufficient electromotive force and capacity. The secondary battery and a capacitor have an active material of an electrode comprising a trimer compound comprising three units of indole or indole derivatives in condensed ring form, wherein the second position and the third position of each unit form a six-membered ring, and a proton which can be utilized as a charge carrier of the trimer compound.

Abstract: By using the polarized electrode for electric double layer capacitor of the present invention, which is produced by mixing powdery activated carbon with a binder, and is characterized by the concentration of an organic compound being not more than 300 (ppm), the amount of organic compounds which remain in the pore of the powdery activated carbon decrease, and a possibility of forming the electric double layer by adsorption of electrolytic ion can be prevented. Thereby, an electric double layer is sufficiently formed inside the pore of the powdery activated carbon, and the diffusion resistance between the powdery activated carbon and the electrolyte becomes low. By constituting as such, an electric double layer capacitor with a large electrostatic capacity and a little internal resistance can be obtained.

Abstract: An electric double layer capacitor is provided with a cell, in which a pair of polarizable electrodes, which are impregnated with an electrolyte, are disposed in opposition on either side of a separator; wherein the polarizable electrodes are provided with collector electrodes, and a peripheral portion of the cell is sealed by a sealing member composed of synthetic resin. The collector electrodes are composed of an alloy made of crystal grains of differing components and the collector electrodes pass through the sealing member while in intimate contact with the sealing member, extending to the outside of the sealing member. A metal plated layer made of crystal grains of a single component is formed on those locations on the collector electrodes that pass through the sealing member.

Abstract: A surface mount energy storage device in the form of a supercapacitor (1) includes a generally rectangular folded prismatic housing (2) and two energy storage elements (not shown) that are sealingly contained within the housing (2) and which are connected in series. A mount, in the form of an integrally formed tinned metal frame (3), extends about and captively retains housing (2) in the folded configuration shown. Two terminals, in the form of elongate contacts (4, 5) extend from the energy storage elements and terminate outside housing (2) for allowing external electrical connection to the elements.

Abstract: The present invention provides an electrode for an electric double layer capacitor which enhances an adhesive property between an electrode layer and an etched aluminum foil current collector. An electrode for a capacitor, includes a current collector, an undercoat layer on the current collector, and an electrode layer on the undercoat layer, wherein the current collector is made of an aluminum foil; the undercoat layer includes at least electrically conductive particles (P) and a binder (B) in a weight ratio P/B of 0.25 to 2.33, and the binder (B) includes a fluorine-containing polymer as a main component; and the electrode layer includes at least a carbon material and a binder.

Abstract: A solid electrolytic capacitor includes a valve metal support, a dielectric layer, a solid polymer electrolyte layer, and an insulating layer. The valve metal support has an opening formed about an anode terminal forming area except for a part of surroundings thereof. The dielectric layer is formed on a surface of the valve metal support so as to expose a part of the anode forming area. The solid polymer electrolyte layer is formed on the dielectric layer. The solid electrolytic capacitor is provided with the insulating layer for electrically insulating the anode terminal forming area in the valve metal support and the solid polymer electrolyte layer from each other.

Abstract: A solid electrolytic capacitor is provided with: an anode employing tantalum; a dielectric layer formed on said anode; and a cathode layer formed on said dielectric layer. The dielectric layer contains tantalum oxide and fluorine.

Abstract: An electrode assembly in embodiments of the invention can include a unitary member formed from an electrically conductive material having a central portion, and tab and plate portions extending radially outward from the central portion. The unitary member can be folded to configure the plate portions in a stacked configuration, thereby providing an electrically connected support structure for a cathode and/or anode assembly without individual connections/welds of plates to a common connection. The elimination of multiple welds lowers the internal resistance of the electrode assembly, and improves the structural integrity. Embodiments of the invention include batteries and implantable medical devices (IMDs) which incorporate the design flexibility in the shape and contour of the electrode assembly and hence, the overall shape and design of batteries and IMDs.

Abstract: Secondary batteries and capacitors have a high electromotive force together with a high cyclic property and are capable of fast charging and discharging, using a polymeric compound having a high stability and high reactivity in an acidic ambient, as an electrode active material. The secondary batteries and capacitors include an indole polymeric compound as an electrode active material. The polymeric compound uses a proton as a charge carrier and has a constituent represented by general formula (1): wherein each R denotes a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, a sulfonic group, a sulfuric acid group, a nitro group, a cyano group, an alkyl group, an aryl group, an alkoxyl group, an amino group, an alkylthio group and an arylthio group, which may be the same or different from each other, and at least one R is a substituent other than a hydrogen atom.

Abstract: An implantable cardioverter-defibrillator has a housing containing cardioverter-defibrillator circuitry and a capacitor assembly. The capacitor assembly includes at least two flat capacitors each having opposed major surfaces. Each capacitor has an anode contact at one major surface, and a cathode contact at the opposite major surface. The anode contact of one of the capacitors contacts the cathode contact of the other. Each capacitor contact may be a thin metal plate covering the entire surface of the capacitor, with each plate connected to corresponding interleaved cathode or anode flat sheets between the plates. A non-conductive perimeter may enclose the sheets and connect the plates to each other.

Abstract: A capacitor having a tantalum or tantalum alloy electrode as one of the electrodes with an outgoing lead wire composed of a novel niobium alloy. According to the present invention, a capacitor having good heat resistance property can be inexpensively provided without reducing the capacitance.

Abstract: A charge storage device comprising: a first electrode, a second electrode being opposed to and spaced apart from the first electrode; a porous separator disposed between the electrodes; a sealed package for containing the electrodes, the separator and an electrolyte in which the electrodes are immersed; and a first terminal and a second terminal being electrically connected to the first electrode and the second electrode respectively and both extending from the package to allow external electrical connection to the respective electrodes, wherein the gravimetric FOM of the device is greater than about 2.1 Watts/gram.

Abstract: Provided in the present invention is a positive electrode for use in an Electric Double Layer (EDL) Hybrid Electrochemical Capacitor (HEC). Embodiments of the invention can be further adapted produce an EDL HEC with a high specific energy value and a high maximum voltage value. Some aspects of an embodiment of the present invention, including the aforementioned positive electrode, also cooperate to provide an EDL HEC that has a relatively high cycleability.

Abstract: The present invention relates to electrolytic capacitors and, more particularly, to the reduction of water content within an electrolytic capacitor. Aluminum electrolytic capacitors tend to degrade with time. This is due, in part, to water in the electrolyte attacking the thin film of aluminum oxide (Al2O3) formed on the anode surface. Deformation of the aluminum oxide increases the leakage current of the capacitor, such that when one or more capacitors are used for shock delivery in an ICD, the first shock (after a hiatus) will have a significantly longer charge time. Unfortunately, one cannot remove all of the water from the electrolyte, as it is needed for conduction, as well as for the formation of the cut edges of the aluminum foil after assembly. According to the present invention, a desiccant material is used within an electrolytic capacitor casing to reduce the water content of a finished capacitor to below 1% by weight of the electrolyte.

Abstract: The present invention relates generally to capacitor cells and the utilization of separator materials that interact with one or more surfactants in such cells. More specifically, the present invention is related to capacitor cells that include separators that are impregnated with a surfactant or that absorb and/or interact with a surfactant that is included in an electrolyte placed within the capacitor cell.

Abstract: A laminated electronic actuator includes a pole-like laminate obtained by alternately laminating a plurality of dielectric layers and a plurality of internal electrode layers one upon the other, and two external electrode plates provided on the opposing side surfaces of the pole-like laminate, the two external electrode plates being electrically connected to every other internal electrode layer, and the one external electrode plate and the other external electrode plate being electrically connected to the different internal electrode layers. The side surfaces of the pole-like laminate on where no external electrode plate is proved have ion concentrations that are suppressed to be not higher than 10 ?g/cm2. Even when the actuator is operated by applying a high voltage, the internal electrodes are not short-circuited, effectively suppressing a change in the amount of displacement.

Abstract: This invention relates generally to capacitor cells and the utilization of enhanced metalized separators in such cells. The metalized separators of the present invention generally include a separator base material, such as a Kraft paper, track etched material, or a microporous polymeric sheet, that supports a cathode and/or anode film operably adjoined to one or both surfaces.

Abstract: A solid electrolytic capacitor has a structure in which a dielectric layer and a metal layer are formed in this order on the surface of an anode. The anode is composed of a porous sinter of tantalum particles. The dielectric layer is composed of a dielectric oxide film formed by anodizing the surface of the anode in an aqueous solution consisting of phosphoric acid, for example. The metal layer is formed by preparing a silver paste by mixing silver particles having an average particle diameter of not larger than 0.05 ?m, a protective colloid, and an organic solvent, and applying the silver paste on the surface of the dielectric layer, and drying the silver paste at a temperature of 150° C. or higher. Further, the anode is connected with an anode terminal, and the metal layer is connected with a cathode terminal through a conductive adhesive.

Abstract: A capacitor and a method for assembling a capacitor. A capacitor is assembled from a case, which contains an anode that is electrically insulated from the case by isolators. A washer is placed above the anode. This washer transfers force from a capacitor cap to the isolators and anode, securing the anode in place. A cap is placed on the case. The cap may be shaped as a toroid with an outer and an inner annular wall. The annular walls may meet at the top and have an opening at the bottom creating a cap cavity in order to store electrolyte or other materials in the cap. The cap also supports a glass seal that insulates the lead tube and lead wire coming from the anode. Once assembled, the capacitor is filled with electrolyte. A weld extends around the cap to secure the cap to the case. The weld may be administered from the top of the capacitor.

Abstract: It is acknowledged that an electric double layer capacitor is markedly superior in power density and cycle characteristics to a secondary battery. However, a higher energy density is required to apply it to a power supply of hybrid vehicle, electric vehicle or the like. The present inventors have found that a carbonaceous material containing copper or a compound of copper exhibits excellent characteristics as an electrode material for capacitor and can realize a capacitor having a large capacity. In the electrode material and the capacitor, copper or a compound of copper exists in the amount of 0.8 to 30 parts by weight calculated on the metal basis based on 100 parts by weight of the carbonaceous material, particularly preferably.

Abstract: The invention relates to a double layer capacitor comprising: at least a pair of current collector plates that are placed in parallel to each other, flat electrodes containing aqueous electrolyte printed on opposing faces of said current collectors, such that a peripheral region is defined on each of said faces of said current collectors, which region is not covered by said electrode, and a separator interposed between said electrodes, the geometric form and size of said separator being identical to the form and size of said current collector plates, said separator having a central region permeable to said electrolyte, surrounded by a peripheral masked region which is non-permeable to said electrolyte, such that the permeable region of said separator coincide with the electrodes printed on the opposing faces of said current collectors, with respect to position, geometric form and size; wherein the pores in the peripheral region of the separator are impregnated with a suitable sealant, and wherein one or more

Abstract: A niobium powder for a capacitor having a tapping density of 0.5 to 2.5 g/ml, and average particle size of 10 to 1000 ?mum, angle of repose form 10° to 60°, the BET specific surface area from 0.5 to 40 m2/g and a plurity of pore diameter peak tops in the pore distribution, and a producing method therof; (2) a niobium sintered body, which is obtained by sintering the above niobium powder and, having a plurality of pore diameter peak tops in a range of 0.01 ?mum to 500 ?mum, preferably, the peak tops of two peaks among the plurality of pore diameter peak tops having a highest relative intensity are present in the range of 0.2 to 0.7 ?mum and in the range of 0.7 to 3 ?mum, respectively, and a producing method thereof; (3) a capacitor using the above sintered body and a producing method thereof, and (4) an electronic circuit and electronic device using the above capacitor.

Abstract: To provide a capacitor capable of utilizing carbon nanotube characteristics effectively to obtain excellent electric or mechanical characteristics, and a method of manufacturing the same. The capacitor is characterized by including two opposing electrodes, at least one of the two electrodes being formed from a coating film of a carbon nanotube structure in which plural carbon nanotubes with functional groups bonded constitute a mesh structure by cross-linking the functional groups through chemical bonding. The method of manufacturing a capacitor includes: a coating step for coating a surface of a base body with a solution that contains plural carbon nanotubes with functional groups bonded; and a cross-linking step for forming a carbon nanotube structure layer in which the functional groups are chemically bonded to one another, thereby causing the carbon nanotubes to cross-link to one another and build a mesh structure.

Abstract: Electrolytic capacitor powder substrates are provided of refractory metal nitrides to reduce instability at a substrate-oxide (as formed) interface whereby the resultant capacitor sensitivity to hear, bias and frequency is reduced.

Abstract: Implantable medical devices (IMDs) and components, including flat electrolytic capacitors and methods of making and using same, particularly an improved electrolytic capacitor fabricated of an electrode stack assembly comprising a plurality of capacitor layers stacked in registration upon one another. Each capacitor layer comprises a valve metal cathode layer having a cathode tab, a valve metal anode layer having an anode tab, and a separator layer located between the cathode layers. The anode layer is assembled from a plurality of valve metal anode sheets that are etched and anodized, stacked side-by-side, and electrically and mechanically joined together by laser weld beads. A valve metal anode tab having a thickness equal to one or more anode sheet is inserted into a tab notch in one or more stacked anode sheet and joined to the anode sheet stack by laser welding the tab and sheet edges together.

Abstract: A charge storage device comprising: a first electrode; a second electrode being opposed to and spaced apart from the first electrode; a porous separator disposed between the electrodes; a sealed package for containing the electrodes, the separator and an electrolyte in which the electrodes are immersed; and a first terminal and a second terminal being electrically connected to the first electrode and the second electrode respectively and both extending from the package to allow external electrical connection to the respective electrodes, wherein the gravimetric FOM of the device is greater than about 2.1 Watts/gram.

Abstract: In an electrode for an electric double layer capacitor of the present invention, the peak value of particle size distribution of graphite particles added to a conductive adhesive is in a range of 2.6 to 3.2 ?m, not less than 100,000 dimples having a largest outer diameter in a range of 4 to 10 ?m and a depth in a range of 4 to 15 ?m are formed on the surface of the collector sheet per 1 cm2, and the occupied area of the dimples to the entire surface area of the collector sheet is not more than 50%. By determining the saponification value of polyvinylalcohol which is used as a binder component of the conductive adhesive in a range of 90.0 to 98.5, adhesiveness of the collector sheet and the electrode forming sheet is improved. Furthermore, by substituting H atoms contained in the polyvinylalcohol with Si atoms, adhesiveness of the collector sheet and the electrode forming sheet can be further improved.

Abstract: An anode (14, 208, 410) and/or cathode (12, 212, 420) of a capacitor has a large surface area. The high surface area of the anode is provided by forming the anode from a thin, electrically conductive layer (16) formed from metal particles (18) or an electrically conductive metallic sponge (416). These materials provide a porous structure with a large surface area of high accessibility. The particles are preferably directional or non-directional sponge particles of a metal, such as titanium. The conductive layer has a dielectric film (36, 236, 414) on its surface, formed by anodizing the particle surfaces. The dielectric film has a combination of high dielectric constant and high dielectric strength. The cathode (12, 212, 420) of the capacitor is either a conventional solid material or, more preferably, has a large surface provided by forming the surface from a sponge or particles analogously to the anode.

Abstract: An object of the present invention is to provide an antimony-containing niobium sintered body for a capacitor having a small specific leakage current value, an antimony-containing niobium powder for use in the sintered body, and a capacitor using the sintered body. In the present invention, an antimony-containing niobium powder having an antimony content of preferably about 0.1 to about 10 mol % and an average particle size of preferably about 0.2 to about 5 ?m is used. By using this antimony-containing niobium powder, a sintered body and a capacitor are constructed.

Abstract: Non-aqueous electrolytic solutions suitable for anodizing valve metal derivative anodes, methods of anodizing using non-aqueous electrolytic solutions, and capacitors prepared with non-aqueous electrolytic solutions. The non-aqueous electrolytic solution comprises glycerine and at least one soluble salt formed by the neutralization of at least one non-halogen-containing organic or inorganic acid anion with at least one alkali metal, ammonium, or protonated amine cation; wherein the acid anion is derived from an acid having a pKa lower than phosphoric acid.

Abstract: An electrode includes a current collector that is two-dimensional in shape and that contains perforations, and an intermediate layer that is electrically conductive and substantially corrosion-resistant. The intermediate layer is on at least part of a first surface of the current collector, and includes at least one of precious metal, graphitic carbon, a metal nitride, and a metal carbide. A first electrode layer is on the intermediate layer. At least part of the first electrode layer is in at least some perforations of the current collector. The first electrode layer, the intermediate layer, and the current collector are bonded together.

Abstract: A raw material composite 10 for a carbon material used in an electric double layer capacitor contains microcrystalline carbon having a layered crystal structure similar to graphite, and is formed a carbon material for an electric double layer capacitor by undergoing an activation treatment. Here, the raw material composite is characterized in that a Hardgrove grindability index HGI defined by ASTMD-409-71 is 50 or above, an interlayer distance d002 of the microcrystalline carbon determined by an X-ray diffraction method is 0.343 NM or below, and a crystallite size Lc002 of the microcrystalline carbon determined by the X-ray diffraction method is 3.0 nm or below.

Abstract: A method to produce a layer electrode for electrochemical components with a layer applied to a metal film to produce a connection between the metal film and the layer by softening the metal film and pressing a surface section of the layer over a part of the thickness of the layer into the softened metal film. The ohmic resistance of the layer electrode can be reduced in an advantageous manner via the pressing of surface sections of the layer into the metal film.

Abstract: An electric double layer capacitor, including at least one basic cell, an electrode plate, and an outer package which covers the basic cell and the electrode plate in a decompression state. The basic cell may be laminated in its thickness direction to form a layered cell and includes a separator, a pair of polarized electrodes disposed so as to sandwich the separator, a pair of collectors disposed so as to sandwich the polarized electrodes, and a gasket disposed between the pair of collectors so as to surround the pair of polarized electrodes. The electrode plate body is attached to each of the collectors located at the outermost side in a laminated direction of the layered cell. A sealing material having a higher gas barrier property than the collectors is disposed so as to seal an interface between the collectors and the electrode plate in the outer package.

Abstract: The invention relates to a niobium powder capable of providing a capacitor having small amounts of leakage current, wherein the average nitrogen concentration in the layer of 50 to 200 nm from the surface to 0.29 to 4% by mass and preferably controlling that in the depth within 50 nm from the surface to 0.19 to 1% by mass, the sintered body, the formed body and the capacitor using the same.

Abstract: A organic electrolytic capacitor comprising a positive electrode, a negative electrode and an aprotic organic solvent of a lithium salt as an electrolytic solution, wherein a positive electrode active material is capable of reversibly holding lithium ions and anions, a negative electrode active material is capable of reversibly holding lithium ions, the negative electrode active material has three times or more capacitance per unit weight as the positive electrode active material, the weight of the positive electrode active material is larger than the weight of the negative electrode active material, and the negative electrode is provided with lithium deposited thereon in advance. Ease of manufacture, high capacity and high withstanding voltage are achieved with this constitution.

Abstract: Electrolytic capacitor for of a high voltage and a high capacity is provided, which is suited for an auxiliary power supply of a fuel cell vehicle. A cathode and an anode foil are arranged to face each other. A dielectric film may be provided on the surface of the anode foil. The anode foil and the cathode foil 4 are wound into a roll, with a compound separator including the first and second separators and arranged there between. In the compound separator, electrolyte is impregnated and conductive fine particles are dispersed in the second separator.

Abstract: A membrane electrode assembly for a polymer electrolyte fuel cell has a polymer electrolyte membrane, an anode, and a cathode having a catalytic layer and a diffusion layer. The alloy catalyst contains ruthenium in the anode diffusion layer. The assembly has less loss of efficiency, particularly when operated at high potentials.

Abstract: A metal collector foil for an electric double layer capacitor is an etched metal collector foil having an oxide film in an amount of not greater than 300 mg/m2, and a capacitance per unit surface area of not less than 150 ?F/cm2. The etched metal collector foil is free from a dielectric layer formed by an anodic formation process on a surface of the etched metal collector foil. A method of producing the metal collector foil and an electric double layer capacitor incorporating therein the metal collector foil are also disclosed.

Abstract: The invention relates to a capacitor with an anode body (1), which is surrounded by a housing (2) having a base surface (3), and having an anode contact (4) that extends outward from the interior of the anode body (1) and features a flat side (5), in which the anode contact (4) is welded to an anode connector (6), in which the anode connector (6) has a soft-solderable material on its surface, and in which a segment (7) of the anode connector (6) running along the base surface (3) of the housing (2) forms a soldering surface (8). The advantage of welding the anode connector (6) to the anode contact (4) is that a soldering surface that is easily soldered by means of soft soldering can be formed on the underside (3) of the housing (2).

Abstract: An electrode with improved operational stability is proposed, in which is provided a two-dimensionally shaped, electrically conductive current collector (1) containing perforations (5). An electrically conductive intermediate layer is applied to the current collector. A first electrode layer (15), which is form-fittingly and firmly bonded to the current collector, is arranged on the intermediate layer on at least one main surface of this current collector, so that a tight interlocking between the current collector and the electrode layer is achieved in the perforations.

Abstract: A capacitor comprising an aluminum case; a capacitor stack mounted within the aluminum case, the capacitor stack comprising one or more anodes and one or more cathodes, one of the one or more anodes and one or more anodes attached to the aluminum case; wherein the case is adapted to be an active capacitor element. In one aspect, a capacitor includes a case having an etched inner surface, the inner surface including an etched upper inner surface and an etched lower inner surface. The capacitor further includes a capacitor stack disposed within the case, where the capacitor stack includes a plurality of cathode stacks and a plurality of anode stacks, and the cathode stacks are electrically coupled with the etched inner surface. The plurality of anode stacks include a first anode stack disposed adjacent to the upper inner surface.

Abstract: Methods of forming tantalum powders and other valve metal powders are described. The method involves high impact milling a starting powder in a fluid medium and optionally a milling media using a high energy mill. The methods of the present invention have the ability to reduce DC leakage and/or increase capacitance capabilities of valve metal powders when formed into capacitor anodes. The methods of present invention further reduce the milling time necessary to form high surface area valve metal powders and leads to reducing contaminant levels in the valve metal powders. The process is particularly well-suited for forming metal flakes, such as tantalum or niobium flakes, of high purity.

Abstract: A process for producing an electric double layer capacitor, which comprises a step of preparing a positive electrode and a negative electrode, each being a carbonaceous electrode containing as the main component a carbon material having a specific surface area of from 100 to 2,500 m2/g, a step of forming an element comprising the positive electrode and the negative electrode and a separator having a thickness of at most 60 &mgr;m interposed therebetween, and a step of impregnating the element with a non-aqueous electrolyte, wherein the copper content in the positive electrode before being impregnated with the non-aqueous electrolyte is at most 1 ppm.