JP2009289938A - Electric double-layer capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce resistance in an electric double-layer capacitor, for example, for assisting each kind of power supply. <P>SOLUTION: The electric double-layer capacitor includes: an element 1 where anode electrodes 2A, 2B and cathode electrodes 3A, 3B in which polarizing electrode layers 2a, 3a are formed on a collector made of metal foil are laminated with a separator 4 therebetween, and the anode electrodes 2A, 2B and cathode electrodes 3A, 3B are exposed to mutually opposing end faces; an electrolyte for drive impregnated into the element 1; an anode terminal 7 and a cathode terminal 8 joined onto respective electrodes exposed to the opposing end faces of the element 1; an interior film 9 for sealing the element 1 while at least one portion of the anode terminal 7 and cathode terminal 8 is exposed; and an exterior resin 10 for covering the interior film 9. Therefore, with a simple configuration, workability and dimensional precision are improved for cost reduction, and resistance and height are reduced as well. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric double layer capacitor used for various electronic devices, electric devices, portable devices and the like.

  An electric double layer capacitor uses electric energy accumulated in an electric double layer formed at the interface between a polarizable electrode and a driving electrolyte, and such an electric double layer capacitor can be reduced in size. Moreover, as a capacitor capable of charging a large capacity, it is widely used for microcomputers, memories, timer backups, various power supply assists, and the like.

  FIG. 5 is a cross-sectional view showing the structure of this type of conventional electric double layer capacitor. In FIG. 5, 21 is a current collector on the positive electrode side provided with polarizable electrodes 23 on both sides, and 25 is a porous polyethylene. The current collector 21 is inserted into the separator 25, and the opening of the separator 25 is thermally welded to the surface of the upper exposed portion of the current collector 21.

  22 is a negative-side current collector provided with polarizable electrodes 24 on both sides, and 26 is a bag-like separator made of a polyethylene porous film. The current collector 22 is inserted into the separator 26, The opening of the separator 26 is thermally welded to the surface of the upper exposed portion of the current collector 22 so that the portions of the current collectors 21 and 22 exposed from the separators 25 and 26 are upside down. Thus, a laminated body is formed by alternately laminating.

  27 is a first conductor made of aluminum connected by spot welding to the end of the current collector 21 protruding above the laminate, and 28 is an end of the current collector 22 also projecting downward from the stack. It is the 2nd conductor made from aluminum connected by spot welding.

  Reference numeral 29 denotes a rectangular exterior member made of a polypropylene box-shaped container 29a and a lid 29b. The laminated body is accommodated in the container 29a together with the driving electrolyte solution. The second conductor 28 is sealed by a lid 29b having a through hole through which the second conductor 28 passes.

  Since the conventional electric double layer capacitor configured in this way can form a large-capacity capacitor by connecting a plurality of cells in parallel, it is excellent in volumetric efficiency in each form and has an electric capacity in each connection portion. The one with a small resistance could be realized.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP-A-7-94374

  However, although the conventional electric double layer capacitor has the characteristics of excellent volume efficiency and low electric resistance, it is difficult to assemble because of the complicated structure, and it is difficult to realize high dimensional accuracy. However, there is a problem that the cost cannot be reduced.

  In addition, there is a problem that further reduction in resistance and height are required due to a request from the equipment used.

  The present invention solves such a conventional problem, and improves the workability and dimensional accuracy with a simple structure, thereby realizing cost reduction and further reduction in resistance and height. An object of the present invention is to provide an electric double layer capacitor.

  In order to solve the above-mentioned problems, the present invention comprises stacking a plurality of layers of an anode electrode and a cathode electrode having a polarizable electrode layer formed on a current collector made of a metal foil with a separator interposed therebetween, An element formed such that the cathode electrode is exposed to the opposite end face, the driving electrolyte impregnated in the element, and at least a part of each of the electrodes exposed to the opposite end face of the element. The anode terminal and the cathode terminal, an interior film in which the element is sealed with at least a part of the anode terminal and the cathode terminal exposed, and an insulating exterior resin covering the interior film It is what.

  As described above, the electric double layer capacitor according to the present invention has a configuration in which an anode terminal and a cathode terminal are connected to each electrode exposed on the opposing end faces of an element in which a plurality of layers of an anode electrode and a cathode electrode are laminated via a separator. The simple structure improves the workability and the dimensional accuracy, thereby realizing a reduction in cost, as well as an effect that a reduction in resistance and a reduction in height can be achieved.

(Embodiment 1)
In the following, the first and third aspects of the present invention will be described with reference to the first embodiment.

  1 is a cross-sectional view showing the configuration of an electric double layer capacitor according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view showing the configuration of elements constituting the electric double layer capacitor. 1 represents an element. The element 1 includes an anode electrode 2A in which a polarizable electrode layer is formed on a current collector made of an aluminum foil and a cathode electrode 3A formed in the same manner between a porous film ( In this embodiment, the anode electrode 2A and the cathode electrode 3A are exposed at the opposing end faces by laminating the separator 4 made of PTFE (polytetrafluoroethylene) film having excellent heat resistance). It is formed to do.

  In addition, as a method of manufacturing the element 1, first, the long separators 4 are alternately folded so that they are folded into layers (generally also called zigzag folding). Sheet-like anode electrode 2A on which layer 2a is formed and sheet-like cathode electrode 3A in which polarizable electrode layer 3a is formed on both sides are alternately arranged, and anode electrode on which one side of polarizable electrode layer 2a is formed 2B, and the cathode electrode 3B having the polarizable electrode layer 3a formed on one side thereof is disposed at the uppermost and lowermost stages of the separator 4 so that the polarizable electrode layers 2a and 3a are in contact with the separator 4, respectively. The element 1 configured as described above is not only improved in workability with a simple configuration, but also has an anode electrode between the layers of the folded separator 4. In which it is possible to ensure a high dimensional accuracy by simply inserting the A and the cathode electrode 3A alternately.

  The polarizable electrode layers 2a and 3a formed on the anode electrodes 2A and 2B and the cathode electrodes 3A and 3B, respectively, are formed by kneading activated carbon powder, carbon black, and a binder. Wood powder-based, coconut shell-based, phenolic resin-based, petroleum coke-based, coal coke-based, or pitch-based materials are used. As the binder, a mixture of polytetrafluoroethylene and carboxymethylcellulose water-soluble binder is used.

  The element 1 configured in this way is processed to an extremely thin thickness by being pressed in the vertical direction (stacking direction), but in the present embodiment, the configuration is made easy to understand. For the sake of explanation, it is shown in a state without press working.

  Reference numerals 5 and 6 denote anode collector electrodes and cathode collector electrodes formed on the anode electrodes 2A and 2B and cathode electrodes 3A and 3B, respectively, exposed on the opposing end faces of the element 1, and the anode collector electrode 5 and The cathode current collecting electrode 6 is composed of a non-valve action metal layer formed by heavy film formation using high-speed particle collision called cold spray, but the present invention is not limited to this, It may be formed by applying a conductive material such as silver paste.

  When the anode current collecting electrode 5 and the cathode current collecting electrode 6 are formed, by using a porous film as the material of the separator 4, the bent portion of the separator 4 made of the porous film is clogged. In order to prevent the material for forming the electrode from penetrating the separator 4 and entering the inside of the element 1, the short circuit is prevented. It is possible to perform electrode formation with high accuracy.

  Furthermore, the anode current collecting electrode 5 and the cathode current collecting electrode 6 are formed so as to integrally connect the anode electrodes 2A and 2B and the cathode electrodes 3A and 3B exposed on the opposite end faces of the element 1, thereby increasing the resistance. In addition to being able to reduce, a reduction in height can also be realized.

  In addition, the above cold spray is, for example, a system technology development research study 16-R-17 “Survey research report on innovative member creation using high-speed particle collision” issued by the Japan Mechanical Systems Promotion Association in March 2005. -Summary- "of 3. Summary of research results, Chapter 1 High-speed particle collision technology, (3) Heavy film formation using high-speed particle collision, and technology introduced in the column of direct modeling technology, accelerating metal particles at ultra-high speed By causing the metal particles to collide with the base material, the metal particles are melted by the energy of plastic deformation at the time of the collision, thereby causing the metal particles to adhere to the base material, and a strong adhesion strength can be obtained.

  In the present embodiment, the cold spray is preferably made of zinc or brass, which is a material having a corrosion potential close to that of aluminum that constitutes the anode electrodes 2A and 2B and the cathode electrodes 3A and 3B. The structure is made of zinc, and zinc particles are in a state of being bitten into the anode electrodes 2A and 2B and the cathode electrodes 3A and 3B.

  In the cold spray, the anode electrodes 2A and 2B and the cathode electrodes 3A and 3B are made of aluminum which is a valve action metal. Since a layer is formed and insulated, it is necessary to use a non-valve action metal to prevent this, and it is necessary to replace this non-valve action metal, and is not limited to the above zinc. .

  Reference numerals 7 and 8 denote an anode terminal and a cathode terminal joined to the anode current collecting electrode 5 and the cathode current collecting electrode 6, respectively. The anode terminal 7 and the cathode terminal 8 are made of an L-shaped conductive material such as an aluminum plate, respectively. The one side is joined to the anode current collecting electrode 5 and the cathode current collecting electrode 6, respectively, and the remaining one side is located at the uppermost stage of the element 1 and the lowermost stage of the element 1. Each is joined to the cathode electrode 3B.

  By joining the anode terminal 7 and the cathode terminal 8 formed in an L shape in this way to the element 1, a reaction force acts so that the element 1 compressed by press working returns, or a swelling phenomenon occurs. In such a case, since the element 1 is sandwiched between the anode terminal 7 and the cathode terminal 8, the element 1 does not swell and can exhibit stable performance.

  9 is an insulating material in which the element 1 is sealed in a state where the element 1 is impregnated with a driving electrolyte solution (not shown) and the connection portions 7a and 8a that are part of the anode terminal 7 and the cathode terminal 8 are exposed. It is an interior film, and functions as one cell in this state. Hereinafter, this is called a cell. Moreover, as the said interior film 9, although the epoxy film etc. which were excellent in heat resistance are suitable, if it can satisfy sealing property and heat resistance, it will not be limited to the said material.

In addition, as the driving electrolyte, as a solvent, propylene carbonate, γ-butyrolactone, ethylene carbonate, sulfolane, acetonitrile, dimethyl carbonate, diethyl carbonate, or methyl ethyl carbonate is used, or a mixture of two or more. be able to. As the electrolyte cation, quaternary ammonium, quaternary phosphonium, imidazolium salt can be used, and as the electrolyte anion, BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ or N (CF ₃ SO _{2) 2} ^- in which can be used.

  Reference numeral 10 denotes a cell in which the anode terminal 7 and the cathode terminal 8 are joined and the element 1 impregnated with the driving electrolyte solution is sealed with the interior film 9, and becomes a part of the anode terminal 7 and the cathode terminal 8. An insulating exterior resin coated with the connecting portions 7a and 8a exposed, and as this exterior resin 10, an epoxy resin having excellent heat resistance is suitable. The material is not limited to the above materials as long as the properties can be satisfied.

  The electric double layer capacitor according to the present embodiment configured as described above has an anode on each electrode exposed on the opposite end face of the element 1 in which the anode electrodes 2A and 2B and the cathode electrodes 3A and 3B are laminated via the separator 4. A current collecting electrode 5 and a cathode current collecting electrode 6 are formed, respectively, and an anode terminal 7 and a cathode terminal 8 are joined to the anode current collecting electrode 5 and the cathode current collecting electrode 6, respectively, and this is sealed with an interior film 9, In addition, the structure coated with the exterior resin 10 achieves a low cost by improving workability and dimensional accuracy with a simple structure, and can achieve a low resistance and a low profile. There is an effect.

  Further, the element 1 is sandwiched between the anode terminal 7 and the cathode terminal 8 formed in an L shape, so that the element 1 can be prevented from being swollen and stable performance can be exhibited. It plays.

  In addition, the element 1 impregnated with the driving electrolyte is sealed with the interior film 9 and further covered with the exterior resin 10, so that high sealing performance and high heat resistance can be exhibited. This is a special effect.

  In the present embodiment, the anode current collecting electrode 5 and the cathode current collecting electrode 6 are respectively formed on the electrodes exposed on the opposing end faces of the element 1, and the anode current collecting electrode 5 and the cathode current collecting electrode 6 are formed. However, the present invention is not limited to this, and the anode terminal 7 and the cathode terminal are connected to the electrodes exposed on the opposite end faces of the element 1. 8 may be directly joined, and the same effect can be obtained by such a configuration.

  In the present embodiment, the anode terminal 7 and the cathode terminal 8 respectively joined to the anode current collecting electrode 5 and the cathode current collecting electrode 6 have been described as being formed in an L shape. The shape is not limited to the above, and any shape other than the L-shape may be used as long as the element 1 can be sandwiched. Even in this case, the same effect can be obtained.

(Embodiment 2)
The second aspect of the present invention will be described below with reference to the second embodiment.

  In the present embodiment, the structure of the electric double layer capacitor described in the first embodiment with reference to FIGS. 1 and 2 is partially different, and the other structure is the same as in the first embodiment. Therefore, the same parts are denoted by the same reference numerals and detailed description thereof will be omitted, and only different parts will be described in detail below with reference to the drawings.

  FIG. 3 is a cross-sectional view showing the configuration of an element constituting the electric double layer capacitor according to the second embodiment of the present invention. In FIG. 3, reference numeral 11 denotes an element, and this element 11 is a current collector made of an aluminum foil. A long anode electrode 12 having a polarizable electrode layer 12a formed on one side thereof and a long cathode electrode 13 having a polarizable electrode layer 13a formed on one side of a current collector made of aluminum foil, In this configuration, the separators 14 are overlapped with each other, and are folded back alternately so that the anode electrode 12 and the cathode electrode 13 are exposed at the opposing end surfaces.

  The element 11 according to the present embodiment configured as described above can not only improve workability but also ensure high dimensional accuracy by a simple configuration, similar to the element 1 according to the first embodiment. It has a special effect of becoming.

  The element 11 configured in this manner is processed to have a very thin thickness by being pressed in the vertical direction (stacking direction). However, in the present embodiment, the configuration is easily understood. For the sake of explanation, it is shown in a state without press working.

  Although not shown, the element 11 is impregnated with a driving electrolyte, and an anode current collecting electrode and a cathode current collecting electrode are respectively provided on the anode electrode 12 and the cathode electrode 13 exposed on the opposite end faces of the element 11. An anode terminal and a cathode terminal are joined to the anode current collecting electrode and the cathode current collecting electrode, respectively, and the element 11 is covered with an insulating interior film 9 with a part of the anode terminal and the cathode terminal exposed. The electric double layer capacitor is configured in the same manner as in the first embodiment by sealing and further covering with an insulating exterior resin 10.

(Embodiment 3)
The third aspect of the present invention will be described below with reference to the third embodiment.

  In the present embodiment, an element sealed with the interior film of the electric double layer capacitor described in Embodiment 1 with reference to FIGS. 1 and 2 is used as one cell, and a plurality of the cells are connected to provide an exterior. The point of being integrally covered with the resin is different, and the configuration other than this is the same as in the first embodiment, so the same reference numerals are given to the same parts, and detailed description thereof is omitted, Only different portions will be described in detail below with reference to the drawings.

  4 (a) to 4 (d) are manufacturing process diagrams showing the structure of the electric double layer capacitor according to the third embodiment of the present invention. In FIG. 4, reference numeral 15 denotes a cell, and the cell 15 is the above-described embodiment. As described in Embodiment 1 with reference to FIG. 1, the element 1 impregnated with the driving electrolyte is sealed with the insulating interior film 9, and the anode terminal 7 and the cathode terminal 8 are sealed from the interior film 9. Connection portions 7a and 8a provided at one end are exposed.

  As shown in FIG. 4B, two cells 15 configured as described above are overlapped, and the anode external terminal 16 and the cathode external terminal are connected to the connecting portions 7a and 8a provided on the anode terminal 7 and the cathode terminal 8, respectively. 17 are connected to each other, and, as shown in FIG. 4 (c), after covering with the insulating exterior resin 10 with the anode external terminal 16 and a part of the cathode external terminal 17 exposed to the outside, As shown in FIG. 4D, the electric double layer capacitor according to the present embodiment is configured by bending the anode external terminal 16 and the cathode external terminal 17 exposed from the exterior resin 10 along the exterior resin 10. It is what.

  The electric double layer capacitor according to the present embodiment configured as described above is obtained by connecting and integrating a plurality of cells 15 in addition to the effects obtained by the electric double layer capacitor according to the first and second embodiments. Thus, it is possible to achieve a special effect that it is possible to realize a small size and a large capacity.

  The electric double layer capacitor according to the present invention has the effect of improving the workability and dimensional accuracy with a simple structure to realize low cost and low resistance, and for assisting various power sources. Useful as a field.

Sectional drawing which showed the structure of the electrical double layer capacitor by Embodiment 1 of this invention The perspective view which showed the structure of the element which comprises the same electric double layer capacitor Sectional drawing which showed the structure of the element which comprises the electrical double layer capacitor by Embodiment 2 of this invention (A)-(d) Manufacturing process figure which showed the structure of the electrical double layer capacitor by Embodiment 3 of this invention Sectional view showing the configuration of a conventional electric double layer capacitor

Explanation of symbols

1, 11 Element 2A, 2B, 12 Anode electrode 2a, 3a, 12a, 13a Polarized electrode layer 3A, 3B, 13 Cathode electrode 4, 14 Separator 5 Anode collector electrode 6 Cathode collector electrode 7 Anode terminal 8 Cathode terminal 7a 8a connection part 9 interior film 10 exterior resin 15 cell 16 anode external terminal 17 cathode external terminal

Claims (6)

A plurality of layers of an anode electrode and a cathode electrode having a polarizable electrode layer formed on a current collector made of a metal foil are laminated with a separator interposed therebetween, so that the anode electrode and the cathode electrode are exposed to the opposing end surfaces, respectively. An element formed on the electrode, a driving electrolyte impregnated in the element, an anode terminal and a cathode terminal each of which is bonded at least partially on each electrode exposed on the opposing end surfaces of the element, and the anode An electric double layer capacitor comprising an interior film in which the above element is sealed with at least a part of a terminal and a cathode terminal exposed, and an insulating exterior resin covering the interior film. Anode current collector electrode and cathode current collector electrode are formed on each surface of the anode electrode and cathode electrode, respectively, exposed on the opposing end faces of the element, and the anode current collector electrode and cathode current collector electrode are provided with at least an anode terminal and a cathode terminal. 2. The electric double layer capacitor according to claim 1, wherein a part of each is joined. As an element formed so that the anode electrode and the cathode electrode are exposed on the opposing end faces, a separator folded in a stacked manner by alternately folding back, and a polarizable electrode layer is formed on both sides to be folded into the above-mentioned stacked shape The electric double layer capacitor according to claim 1 or 2, wherein an element comprising a sheet-like anode electrode and a cathode electrode arranged alternately between the respective layers of the separator is used. As an element formed so that the anode electrode and the cathode electrode are exposed on the opposite end surfaces, the anode electrode and cathode electrode each having a polarizable electrode layer formed on one side are superposed with a separator interposed therebetween, and these are alternately arranged. The electric double layer capacitor according to claim 1, wherein the element is folded into a laminated shape by folding. The electric double layer capacitor according to claim 1 or 2, wherein a separator made of a porous film is used as a separator constituting the element. The electric double layer capacitor according to claim 1 or 2, wherein an element sealed with an interior film is used as one cell, and a plurality of the cells are connected and integrally covered with an insulating exterior resin.

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