Abstract: A solid electrolytic capacitor is formed by stacking flat solid electrolytic capacitor elements. Negative electrode sections of a part of the solid electrolytic capacitor elements and negative electrode sections of the remaining part of the solid electrolytic capacitor elements are led out so as to be faced to each other, and are connected to the first and second negative electrode lead frames which are independent to each other, respectively. Two of negative electrode sections are insulated from each other in the solid electrolytic capacitor.

Abstract: A capacitor and a method for assembling a capacitor. A capacitor is assembled from a case, which contains an anode that is electrically coupled to the case and defines wells or slots receiving a plurality of cathode plates. A header is placed on the case. The header also supports a glass seal that insulates the lead tube and cathode lead coming from the cathode. Once assembled, the capacitor is filled with electrolyte. A weld extends around the header to secure the header to the case. A bent cathode configuration enables a plurality of cathode plates electrically coupled together from a common cathode plate.

Abstract: A solid electrolytic capacitor (A) includes a first porous sintered body (1A) made of valve metal, anode conduction members (21A, 21B) electrically connected to the first porous sintered body (1A), surface-mounting anode terminals (3A, 3B) electrically connected to the anode conduction members (21A, 21B), surface-mounting cathode terminals, and a second porous sintered body (1B) made of valve metal and intervening between the first porous sintered body (1A) and the anode conduction members (21A, 21B).

Abstract: In a solid electrolytic capacitor, a path of an electric current flowing from a lower layer to an upper layer of a laminate in cathode portions of respective capacitor elements connected through an electroconductive adhesive layer is opposite to paths of electric currents flowing from a canopy through joints to cathode terminals, thereby achieving reduction in ESL by mutual inductance effect in a simple structure. Since the solid electrolytic capacitor has the structure in which the laminate is surrounded by the canopy and joints, sufficient pressure resistance is ensured for the capacitor elements during resin injection. For this reason, a resin mold to cover the laminate can be formed by transfer molding, which ensures excellent heat resistance and moisture resistance.

Abstract: A capacitor device has a plurality of capacitors, each including a capacitor element having a positive electrode and a negative electrode in a confronting arrangement through a separator, and a metal case encasing the capacitor element and an electrolyte. The plurality of capacitors include a plurality of first capacitors, each using the metal case as a negative electrode, and a plurality of second capacitors, each using the metal case as a positive electrode. The capacitor device is characterized by a structure that a pair of the first capacitor and the second capacitor form a capacitor unit by having their metal cases coupled with a metal plate, a plurality of capacitor units form a subunit by being connected in series or parallel, and a plurality of subunits form a main unit by being connected in series or parallel. The invention helps facilitate connections when coupling the plurality of capacitor units, and substantially reduces a space required for the connections.

Abstract: A solid electrolytic capacitor, including a stack of solid electrolytic capacitor elements each having an anode part and a cathode part. The stacked structure is such that cathode parts of solid electrolytic capacitor elements are stacked one on another to have some misalignment between the stacked elements. The capacitor preferably has a structure in which one end part of the cathode part of at least one of the solid electrolytic capacitor elements stacked on another element is more prominent or retracted than that of the element below.

Abstract: The present invention provides a stacked solid electrolytic capacitor that allows further reducing ESR by increasing the number of stacked layers. The stacked solid electrolytic capacitor according to the present invention is a stacked solid electrolytic capacitor having a plurality of stacked solid electrolytic capacitor elements, and each solid electrolytic capacitor element comprises an anode formed of a valve action metal, an anode section formed on an end of the anode, a dielectric formed on the surface of the valve action metal and comprising an oxide of the valve action metal, and a cathode layer formed on the dielectric. The cathode layers and the anode sections of the solid electrolytic capacitor elements are respectively connected to each other across the plurality of stacked solid electrolytic capacitor elements.

Abstract: A hybrid capacitor is provided which includes a substrate, at least one plate capacitor and at least one through hole capacitor. The substrate has through holes and the plate capacitors are on the substrate. At least one through hole capacitor and at least one plate capacitor are in parallel. The through hole capacitor at least includes an anode layer, a first dielectric layer, a first cathode layer and a second cathode layer. The anode layer is disposed on an inner surface of at least one through hole, and a surface of the anode layer is a porous structure. The first dielectric layer is disposed on the porous structure of the anode layer and covered with the first cathode layer. The first cathode layer is covered with the second cathode layer. A conductivity of the second cathode layer is larger than a conductivity of the first cathode layer.

Abstract: A solid electrolytic capacitor (A1) includes a first and a second porous sintered bodies (1). Each sintered body (1) is flat, with its thickness being small relative to the width or the length. The first and the second sintered bodies (1) are spaced from each other in the widthwise or lengthwise direction.

Abstract: [Problem] Mechanical stress in welding is suppressed, a tilt of the elements is suppressed in relation to the increase in the number of layers so that LC defects are alleviated, whereby an increase in capacitance due to a greater number of layers is achieved. [Means for Solving the Problem] In a solid electrolytic capacitor, capacitor elements (30) are disposed in a stacked state and anode portions (30a) are weld-secured to anode mounting surfaces of anode mounting parts (7a), (7b) provided for an anode terminal. Two anode mounting parts (7a), (7b) are provided, and the anode mounting parts are disposed parallel to each other, and adjacent anode mounting parts (7a), (7b) are joined to each other by a joint part (9).

Abstract: A capacitor a casing of first and second casing members, a feedthrough electrically insulated from the casing and extending there from, first and second anodes electrically connected to each other within the casing, a cathode, and an electrolyte is described. The first anode is electrically connected in parallel to the second anode by a first anode wire having opposite ends contacting the respective first and second anodes. A feedthrough wire extending outside the casing and electrically isolated there from is electrically connected to the first anode wire intermediate the first and second anodes. The cathode is disposed between the first and second anodes.

Abstract: A device includes a base plate, a first cell, a second cell, and a housing in which the-first cell and the second cell are arranged. The first cell and the second cell each include at least one capacitor. The device also includes a first metal plate configured connected to a capacitor in the first cell and second metal plate connected to a capacitor in the second cell. The first and second metal plates each having at least one hole configured to receive the conductive fastening element. The device also includes an electrically conductive fastening element connected through the hole in the first metal plate and the hole in the second metal plate such that the first metal plate and the second metal plate are-electrically connected to one another and mechanically attached to one another and to the base plate.

Abstract: An integrated capacitor assembly that offers improved performance characteristics in a convenient and space-saving package is provided. More specifically, the capacitor assembly contains a first solid electrolytic capacitor element and second solid electrolytic capacitor element positioned adjacent to the first solid electrolytic capacitor element. The first and second solid electrolytic capacitor elements each contain an anode formed from a valve metal composition having a specific charge of about 70,000 ?F*V/g or more, the anode having a thickness of from about 0.1 to about 4 millimeters. A thermally conductive material is positioned between the first and second solid electrolytic capacitor elements and electrically connected thereto. The thermally conductive material has a coefficient of thermal conductivity of about 100 W/m-K or more at a temperature of 20° C. A case encapsulates the first and second solid electrolytic capacitor elements.

Abstract: A capacitor includes a first capacitor element and a second capacitor element laminated on this first capacitor element. The first capacitor element is a solid electrolytic capacitor including a through-hole electrode penetrating a valve metal sheet and having one surface on which cathode and anode terminal portions are taken out. The second capacitor element has first and second electrodes which are provided via a dielectric layer, and second through-hole electrodes penetrating the dielectric layer. The second through-hole electrodes are coupled to the first electrode and insulated from the second electrode. Lead-out portions of the second electrodes are exposed from the dielectric layer. The second through-hole electrodes and the lead-out portions are disposed alternately. The first electrode is electrically coupled to the first through-hole electrode and the second electrode is electrically coupled to the valve metal sheet.

Abstract: A multi-layered solid electrolytic capacitor is furnished with a plurality of capacitor elements 6, each having an aluminum foil 1 having an anode portion 7 and a cathode portion 8 having a dielectric oxide film 2 and a cathode layer 3 successively formed on a surface of the aluminum foil 1. The capacitor elements 6 are stacked on each other. Adjacent anode portions 7 of the capacitor elements 6 are welded to one another and adjacent cathode portions 8 are electrically connected one another by a conductive paste layer 18. An insulative resin layer 16 is disposed on a boundary between the cathode portion 8 and the anode portion 7 of at least one of the capacitor elements 6 and on an adjacent region thereto.

Abstract: The present invention provides a capacitor device including a plurality of capacitor elements adjacent to each other along an axial direction are electrically connected to each other by fitting between a first terminal of one capacitor element and a second terminal of the other capacitor element, a intermediate plate allows the terminals fitted to each other between the capacitor elements adjacent to each other along the axial direction to penetrate through and positions these capacitor elements, an upper plate is electrically connected to the terminals of capacitor elements arranged on one end portion in the axial direction, a lower plate is electrically connected to the terminals of capacitor elements arranged on the other end portion in the axial direction, and all the capacitor elements are held in place by being sandwiched between the upper plate and the lower plate.

Abstract: An integrated capacitor assembly that offers improved performance characteristics in a convenient and space-saving package is provided. More specifically, the capacitor assembly contains a multi-anode stack of at least two electrolytic capacitors and at least one ceramic component, which are connected in parallel to common terminals within an encapsulating case. The resultant capacitor assembly is characterized by such performance characteristics as relatively high capacitance, low ESR, low piezoelectric noise, and space reduction. Reduced piezoelectric noise may be particularly advantageous for providing clear filtering in audio/video data processing and communication.

Abstract: A high voltage capacitor design is provided that provides improved performance. The high voltage capacitor includes a stack of mechanically bonded capacitor cells, which in one variant utilize a separator formed of two layers of paper. In one version, the high voltage capacitor may be used as a capacitative voltage divider.

Abstract: An integrated capacitor assembly that offers improved performance characteristics in a convenient and space-saving package is provided. The capacitor assembly contains multiple discrete solid electrolytic capacitors that are “finished” in the sense that they are provided with leads and encapsulated. This allows each individual capacitor to be tested for performance prior to its incorporation into the capacitor assembly, thereby increasing the product yield and quality. More specifically, because each individual capacitor may be “pre-tested” and “aged”, the likelihood that the final capacitor assembly will fail its performance test is minimal.

Abstract: An integrated capacitor assembly that offers improved performance characteristics in a convenient and space-saving package is provided. More specifically, the capacitor assembly contains a multi-anode stack of at least two electrolytic capacitors and at least one ceramic component, which are connected in parallel to common terminals within an encapsulating case. The resultant capacitor assembly is characterized by such performance characteristics as relatively high capacitance, low ESR, low piezoelectric noise, and space reduction. Reduced piezoelectric noise may be particularly advantageous for providing clear filtering in audio/video data processing and communication.

Abstract: A surface-mount capacitor includes a multilayer capacitor structure formed by laminating plate-like capacitor elements each having anode lead portions 11 at opposite ends thereof and a cathode portion 12 at the center, an anode terminal 18 connected to each anode lead portion 11 via a strip-like plate 14, and a cathode terminal 19 connected to the cathode portion 12. The anode and the cathode terminals 18 and 19 have a flat shape and are formed on a common plane as a substrate-mounted surface. A mold resin case 20 has a bottom portion filling a gap between the anode and the cathode terminals 18 and 19 and mechanically connecting the anode and the cathode terminals 18 and 19, and side walls substantially perpendicular to the substrate-mounted surface. The anode and the cathode terminals 18 and 19 have upper surfaces exposed on an inner bottom surface of the mold resin case 20 to be connected to the anode lead portions 11 and the cathode portion 12.

Abstract: A solid electrolytic capacitor having a plurality of capacitor elements is provided that is small in size and has good electrical characteristics. The solid electrolytic capacitor includes a plurality of capacitor elements each having a dielectric film, a cathode layer, and a cathode lead-out layer formed in succession on a surface of an anode body having an anode lead part, each anode lead part of the capacitor elements connected to an anode terminal, each cathode lead-out layer of the capacitor elements connected to a cathode terminal, and the plurality of capacitor elements covered by a housing made of resin. The capacitor elements 1 are mounted on the cathode terminal 2 at an interval, the cathode terminal 2 is provided with a cathode resin-filling opening 2a, and the resin is filled between the capacitor elements 1 and in the cathode resin-filling opening 2a.

Abstract: A plurality of high capacitance capacitors are coupled to supply or accept large currents. Bus bars are welded to the capacitors to provide improved thermal performance as well as self-supporting rigidity to the geometrical structure formed by the capacitors and the bus bars.

Abstract: A surface-mounted component includes an external contact, and components that are arranged in proximity to each other and that contain terminals. The external contact is connected to the terminals by spot welds. The external contact defines a contact surface on an assembly area of the surface-mounted component. The external contact also has an area that is free of spot welds.

Abstract: Integrated passive component assemblies utilize array shell or array frame receiving structures to isolate and protect discrete passive components and provide a modular configuration for mounting to a substrate. Receiving structure embodiments include a base portion, spacer ribs, and optional side walls. Spacer ribs may be connected or provided in opposing spacer rib portions to effectively isolate adjacent component terminations. Standoff features may be incorporated into select embodiments of the disclosed technology to aid in device mounting and to facilitate post-affixment cleaning and visual termination contact. Discrete passive components in accordance with the present subject matter may include select combinations of resistors, capacitors, inductors, and other suitable devices.

Abstract: High capacitance capacitors are provided to supply or accept large currents. As current flow through a capacitor increases, heat may be generated. Above a certain threshold temperature or current, a capacitor may fail. The present invention addresses capacitor's tendency to fail at higher currents and/or higher temperatures.

Abstract: A housing is provided for connecting two capacitor cells in a series or parallel combination and for providing the two cells as one integral product.

Abstract: A solid electrolytic capacitor having at least two capacitor elements using a valve action metal, such as tantalum or niobium, and laminated in a direction perpendicular to a mounting surface of a substrate. The capacitor elements have a width parallel to the mounting surface of the substrate greater than a thickness perpendicular to the mounting surface of the substrate, and an anode terminal is connected with anode leads led out to at least one side of an anode body made of the valve action metal generally in parallel to the mounting surface of the substrate. A cathode layer on a dielectric oxide film of the anode body is connected to a cathode terminal and is coated with exterior coating resin with a part of the anode terminal and a part of the cathode terminal exposed.

Abstract: Implantable medical devices (IMDS) and their various components, including flat electrolytic capacitors for same, and methods of making and using same, particularly an improved electrolytic capacitor. Methods and apparatus for securely mechanically and electrically attaching anode sheets of multi-sheet anode layers of electrolytic capacitors together in a simple manner that does not without unduly damage adjacent or exposed oxide layers are disclosed. The side-by-side stacked multiple anode sheets of a multi-sheet anode layer are joined together by precision cold welding the anode sheets together wherein deformation of the anode sheets is effected by simultaneously driving one or more set of first and second axially aligned cold weld pins into respective first and second stack sides of the stacked anode sheets to substantially equal cold weld depths.

Abstract: A solid electrolytic capacitor having a plurality of solid electrolytic capacitor elements each having an anode part assigned to one end part of an anode substrate composed of a valve-acting metal having on the surface thereof a dielectric film layer, and a cathode part consisting of a solid electrolyte layer formed on the dielectric film layer in the remaining portion of the anode substrate and an electrically conducting layer formed on the solid electrolyte layer. The anode parts are stacked on one another and the cathode parts are stacked on one another, and the stacked anode parts and stacked cathode parts are connected to a lead frame and are molded with an outer jacket resin. Each solid electrolytic capacitor element has a notched part at least at one part of the cathode part and an electrically conductive material fills the notched part.

Abstract: The present invention aims to provide a circuit module that includes a sheet-like solid electrolytic capacitor and reduces an area and volume required for mounting electronic components. In the sheet-like solid electrolytic capacitor, valve metal sheet 11 has dielectric layer 13 and current collector layer 12 formed on the surface thereof, and is packaged by insulators 14 and 15. The circuit module is structured to embed the sheet-like solid electrolytic capacitor in a circuit board.

Abstract: A solid electrolytic capacitor includes a package 4 for entirely sealing a capacitor element 1, an anode lead terminal 2 connected to an anode wire 1a of the capacitor element 1, and a cathode lead terminal 3 kept in close contact with a side surface of the capacitor element, wherein both leads are exposed at the bottom surface of the package. The anode lead terminal is formed with an upwardly bent piece 2a provided with a positioning groove 2b. The anode wire of the capacitor element is fitted in the positioning groove, so that the upwardly bent piece completely bridges the gap between the anode wire and the anode lead terminal while accurately positioning the capacitor element at the center widthwise of the anode lead terminal and the cathode lead terminal.

Abstract: A supercapacitor comprising a poly(3,4-ethylendioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT) as electrode couples for the capacitor and a pair of gel electrolyte layers disposed between the electrodes. The gel electrolytes are separated by a battery paper and are selected from a group consisting of a lithium salt and an organic electrolyte.

Abstract: A solid electrolytic capacitor is obtained by mounting a plurality of single plate capacitor elements within a chip by employing a stacking structure such as parallel stacking, opposing stacking, each layer-opposing stacking or closest stacking. As a result, a compact and high-capacitance element can be easily manufactured. The single plate capacitor element is preferably an element having an unfolded fan-like shape.

Abstract: A flow-through capacitor and fluid for the purification system wherein the flow-through capacitor comprises a plurality of individuals, electrolyte-isolated cells (7), and the cells are electrically connected in series in a cartridge holder.

Abstract: A method of making a flat capacitor includes forming at least one recess on an inside surface of a metal foil blank, leaving a surrounding peripheral flange. A coating performing as an electrode of the capacitor is applied to the inside surface of the metal foil blank and an ion-permeable separator is placed on that inside surface of the metal foil blank. A substantially planar anode with a protruding lead is placed in the recess with the lead extending through a hole of the metal foil blank. Thereafter, the metal foil blank is folded along a line intersecting the hole so that the anode is sandwiched between parts of the separator and the separator is in contact with the coating on the inside surface of the metal foil blank. In the folding process, parts of the peripheral flange of the metal foil blank are brought into contact with each other and these parts are sealed to each other to form a hermetically sealed metal foil case of the capacitor.

Abstract: Flat electrolytic capacitors particularly for use in implantable medical devices having stacked cathode and anode layers particular electrical connections of the capacitor anode and cathode layers with a capacitor connector assembly. Anode terminal means extend through the capacitor case side wall for electrically connecting a plurality of the anode tabs to one another and providing an anode connection terminal at the exterior of the case that is electrically insulated from the case. A cathode terminal extends through or to an encapsulation area of the capacitor case side wall via a cathode terminal passageway for electrically connecting a plurality of the cathode tabs to one another and providing a cathode connection terminal at the exterior of the case. The connector assembly is electrically attached to the anode connection terminal for making electrical connection with the anode tabs and to the cathode connection terminal for making electrical connection with the cathode tabs.

Abstract: A solid electrolytic capacitor capable of realizing miniaturization and large capacitance and obtaining the connection, in particular electric connection between the anodes, with low resistance and high reliability. A solid electrolytic capacitor includes: a laminate including a plurality of capacitor units in which a dielectric layer and a solid electrolytic layer are laminated in this order on a predetermined surface of an anode made of a valve metal; a sealing body for sealing the laminate; and an anodic conductive elastic body formed outside the sealing body and electrically connected to the anode. The anodes are adhered to each other via the conductive elastic body. In the solid electrolytic capacitor, a part of the anode is exposed to the outside of the sealing portion and the exposed portion is covered with a plating layer, and electrically connected to the anodic conductive elastic body via the covered exposed portion.

Abstract: A simple method of mass producing a plurality of solid electrolytic capacitor elopements can be performed to produce capacitors with reduced leakage current and excellent reliability. The method includes supplying a band metal, a first portion of which contains protrusions on which a dielectric layer, then a conductor layer are formed. A conductive polymer film is formed on the conductor layer by electrolytic polymerization starting from a conductive tape adhered on a second portion of the band metal. The conductive tape acts as a common positive electrode for polymerization and a plurality of electrodes connected independently to the protrusions as negative electrodes. Finally a plurality of capacitor elements are formed by laminating individual protrusions cut off from the band metal.

Abstract: A solid electrolytic capacitor is provided which includes a capacitor element having an anode and a cathode, a sheet member for mounting the capacitor element, and a protection package formed on the sheet member to enclose the capacitor element. The sheet member is provided with an anode terminal and a cathode terminal which are connected to the anode and the cathode, respectively.

Abstract: A capacitor terminal is described, in particular for an electrolyte power capacitor, with which the capacitor is mechanically and electrically connected to a fastening part and/or to electric conductors. The capacitor terminal on the capacitor itself is designed as a contact stud having a relatively long, smooth contact area. The contact stud is designed in the form of a cylinder having a round or oval cross section or a rectangular tube connection. The part accommodating the contact stud is composed of a contact spring accommodating the contact stud for mechanical fixation and to establish the electric contact and which is attached to a connection strip. An extra spring can surround the contact spring in a ring to increase the contact force. Multiple capacitors may be connected to the connection strip by a simple plug-in technique, i.e.

Abstract: A capacitor module capable of forming assembly of capacitors is disclosed. The capacitor is contained into a housing and the housing has a male connector and a female connector formed on the opposite sides thereof. The housings can combine each other by the engagement of the male and female connectors so as to achieve the housing assembly. After that, link bars are used to connect the corresponding electrodes of each capacitor, and a cover and a base are mounted on the top and the bottom of the capacitor module.

Abstract: A laminated capacitor and a process for producing the same. The laminated capacitor includes a plurality of capacitor assemblies and external electrodes, the capacitor assemblies each including a thermoplastic resin film having consecutively thereon a metal film as a first internal electrode, an inorganic dielectric material film, and a metal film as a second internal electrode, the plurality of capacitor assemblies being laminated with each other to form a laminated body, the external electrodes each being provided on an end surface of the laminated body, on which the first or second internal electrode is exposed, and being electrically connected to the first and second internal electrodes, respectively.

Abstract: A dry preunit (10), includes a plurality of cells (110, 112, 114) in a true bipolar configuration, which are stacked and bonded together, to impart to the device an integral and unitary construction. Each cell (114) includes two electrically conductive electrodes (111A, 111B) that are spaced apart by a predetermined distance. The cell (114) also includes two identical dielectric gaskets (121, 123) that are interposed, in registration with each other, between the electrodes (111A, 111B), for separating and electrically insulating these electrodes. When the electrodes (111A, 111B), and the gaskets (121, 123) are bonded together, at least one fill gap (130) is formed for each cell. Each cell (114) also includes a porous and conductive coating layer (119, 120) that is formed on one surface of each electrode. The coating layer (119) includes a set of closely spaced-apart peripheral microprotrusions (125), and a set of distally spaced-apart central microprotrusions (127).

Abstract: An electrochemical capacitor chip device (10) includes a plurality of capacitor subassemblies (12, 14, 16, 18, 20, and 22) arranged in stacked configuration. Each stacked capacitor assembly shares a single common electrode (48) from which extends a contact tab. Attached to contact tabs are lead pins (26, 28, 30 and 32) for effecting electrical and mechanical communication with, for example, a printed circuit board. The capacitor subassemblies may be preferably fabricated of electrochemical capacitor subassemblies employing gelled polymeric electrolyte structures.

Abstract: A capacitor includes a cathode having a porous coating including an oxide of one of ruthenium, iridium, nickel, rhodiumm platinum, palladium, and osmium, an anode including a metal selected from the group consisting of tantalum, aluminum, niobium, zirconium, and titanium, spaced from the porous coating, and an electrolyte in contact with the porous coating and the anode.

Abstract: An electrode for an energy storage device is made from an activated carbon support. The activated carbon has adsorbed onto it a protonated polymer, which has a polyoxometalate absorbed into the polymer. Preferably, the protonated polymer is poly(4-vinylpyridine), and the polyoxometalate is isopolymolybdate. An energy storage device, such as a capacitor, can be made from the modified carbon electrode. A pair of the coated carbon electrodes (13) are placed in contact with an electrolyte to form the device.

Abstract: A capacitor module for use with an IGBT including an epoxy housing having two holes completely therethrough. Within the housing are two wound capacitors which are connected in parallel. Additionally, there are two mounting inserts which at least partially line the holes of the housing. The wound capacitors are also connected to the first and second mounting inserts which serve as the terminals for the capacitor module. As a result, the capacitor module exhibits very low self-inductance as well as very low ESR.

Abstract: A capacitor includes a cathode having a porous coating including an oxide of one of ruthenium, iridium, nickel, rhodium, platinum, palladium, and osmium, an anode including a metal selected from the group consisting of tantalum, aluminum, niobium, zirconium, and titanium, spaced from the porous coating, and an electrolyte in contact with the porous coating and the anode.

Abstract: An electric double layer capacitor having a rectangular cross-section for an excellent volumetric efficiency and a low internal resistance is disclosed. The capacitor comprises a plurality of sheet-like current collectors in one polarity and in the other polarity; the surfaces of the both collectors are formed into polarizable electrodes composed mainly of activated carbon with a binder; a plurality of separators interposed between the current collectors of the one polarity and those of the other polarity.