JP2008177322A - Capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitor used for a hybrid automobile or the like of which the driving electrolyte is prevented from leaking to the outside for improved reliability. <P>SOLUTION: The capacitor comprises an element 1 of which positive and negative electrodes are formed on facing end faces, a metal case 2 which houses the element 1 together with a driving electrolyte, with a negative electrode 1c of the element 1 jointed to an inner bottom surface, a terminal plate 3 of which the positive electrode 1b of the element 1 is jointed to an inner surface with an opening part of the metal case 2 sealed, and a pressure adjusting valve 7 which is connected to the upper surface side of a communication hole formed at the terminal plate 3. At least the positive electrode 1b of the element 1 of at a part which abuts on the communication hole formed at the terminal plate 3 is partially recessed not to contact with the communication hole. By this configuration, the entering of the driving electrolyte into the communication hole is suppressed to prevent liquid pooling, thereby not causing the leaking of the driving electrolyte to the outside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a capacitor used for regeneration of various electronic devices and hybrid vehicles, or for power storage.

  FIG. 7 is a sectional view showing the configuration of an electric double layer capacitor as an example of this type of conventional capacitor, and FIG. 8 is a sectional view showing the configuration of a pressure regulating valve provided in the electric double layer capacitor. 7 and 8, reference numeral 20 denotes an element, and the element 20 is configured to take out the anode and the cathode from both end faces (vertical direction in FIG. 7), respectively.

  Reference numeral 21 denotes an aluminum metal case containing the element 20 together with a driving electrolyte (not shown). One end face of the element 20 is mechanically and electrically joined to the inner bottom surface of the metal case 21 by laser welding or the like. It is what you do.

  22 is an aluminum sealing plate, 22a is an electrolyte injection hole provided in the sealing plate 22, 23 is a pressure regulating valve, and the other end surface of the element 20 is mechanically bonded to the inner surface of the sealing plate 22 by laser welding or the like. It is configured to be joined by electrical and electrical joining and sealed by processing so as to wind the opening of the metal case 21 on the periphery of the sealing plate 22.

  Further, as shown in detail in FIG. 8, the pressure regulating valve 23 has a gas permeable member 24 and a closing body 25 on the electrolyte injection hole 22a, and has a hole 26a that communicates these with the outside. The metal cap 26 is fixed so as to be covered, and the closing body 25 is always urged in the closing direction. The metal cap 26 is fixed in advance by surrounding the electrolyte injection hole 22a around the sealing plate 22. The annular protrusion 22b provided in this way is fixed by being deformed by caulking or the like and pressed against the metal cap 26.

  The conventional electric double layer capacitor configured as described above can reduce the places where the drive electrolyte may leak by disposing and fixing the pressure regulating valve 23 in the electrolyte injection hole 22a. In other words, a more reliable electric double layer capacitor can be obtained.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2004-134632 A

  However, in the above-described conventional electric double layer capacitor, the pressure regulating valve 23 is a self-returning type, and the gas permeable member 24 prevents the driving electrolyte from adhering to the closing body 25. Although it is possible to prevent the driving electrolyte from leaking to the outside of the capacitor through the valve 23, the driving electrolyte is easily circulated into the electrolyte injection hole 22a provided in the terminal plate 22. There is a problem, and the driving electrolyte that has entered the electrolyte injection hole 22a adheres to the inner wall of the hole in a ball shape (hereinafter referred to as a liquid pool phenomenon), and such a liquid pool phenomenon is normal. In other words, when the internal pressure of the capacitor rises due to some factor, the driving electrolyte passes through the interface between the gas permeable member 24 and the terminal plate 22 and adheres to the closing body 25. Were those having a problem that in the worst case there is a possibility that driving electrolyte leaks to the outside.

  An object of the present invention is to solve such a conventional problem and to provide a capacitor having a highly reliable pressure regulating valve that prevents a driving electrolyte from leaking to the outside by preventing a liquid pool phenomenon. To do.

  In order to solve the above-described problems, the present invention includes an element in which positive and negative electrodes are formed on opposite end surfaces, the element together with a driving electrolyte, and one electrode of the element bonded to the inner bottom surface. A metal case, a terminal plate in which the other electrode of the element is joined to the inner surface and the opening of the metal case is sealed, and a communication hole provided in the terminal plate is closed on the upper surface side of the terminal plate. It is composed of a pressure regulating valve that is coupled, and has a configuration in which at least the electrode portion of the element that contacts the communication hole provided in the terminal plate is partially recessed so as not to contact the communication hole.

  As described above, the capacitor according to the present invention has a configuration in which the electrode portion of the element in contact with the communication hole of the terminal plate connected to the upper surface side of the pressure regulating valve is partially recessed so as not to contact the communication hole. As a result, it is possible to greatly reduce the amount of driving electrolyte impregnated in the element from entering the communication hole. The phenomenon can be suppressed, and as a result, the effect that the driving electrolyte does not leak to the outside can be obtained.

(Embodiment 1)
Hereinafter, the first aspect of the present invention will be described with reference to the first embodiment.

  1A to 1C are a plan view, a front sectional view, and a bottom view showing a configuration of an electric double layer capacitor as an example of a capacitor according to Embodiment 1 of the present invention, and FIG. 2 shows the electric double layer. It is sectional drawing which showed the structure of the pressure regulating valve provided in the capacitor. In FIG.1 and FIG.2, 1 shows an element, 1a shows the hollow part formed in this element 1, This element 1 is made from aluminum foil. A pair of positive and negative electrodes in which a polarizable electrode layer is formed except for one end on the current collector are stacked in opposite directions, and wound with a separator interposed therebetween (all not shown). Each polarizable electrode layer-unformed portion of the electrode is configured to be exposed at the opposing end surface, and the anode electrode portion 1b and the cathode electrode portion 1c are taken out from both end surfaces (vertical direction in FIG. 1) of the element 1, respectively. It is a thing.

  2 is a bottomed cylindrical metal case made of aluminum containing the element 1 together with a driving electrolyte solution (not shown), and a cathode electrode portion provided on one end face of the element 1 inserted into the metal case 2 1c is mechanically and electrically joined by laser welding (welding mark 2b) to an element joint portion 2a provided in a partially convex shape on the inner bottom surface of the metal case 2. The electrode (negative electrode) is taken out from the metal case 2.

  3 is an aluminum terminal plate, 3a is a columnar projection provided on the inner surface of the terminal plate 3, and 3b is an element joint provided by being partially formed on the inner surface. 3a is fitted into the hollow portion 1a of the element 1, and the anode electrode portion 1b provided on the other end surface of the element 1 is laser-welded (welding mark 3c) to the element joint portion 3b to be mechanically and electrically The other electrode (positive electrode) of the element 1 is taken out from the terminal plate 3.

  Reference numeral 4 denotes an annular insulating member having an L-shaped cross section, which is disposed between the outer peripheral surface of the terminal plate 3 and the inner peripheral surface of the metal case 2 and insulates the two, and 5 is disposed on the upper surface periphery of the terminal plate 3. It is a sealing rubber which is compressed and sealed by curling the open end of the metal case 2.

  6 is a rubber plug for closing an electrolyte injection hole (not shown) provided in the terminal plate 3, and 7 is a pressure regulating valve mounted so as to close the communication hole 3 d provided in the terminal plate 3. The pressure regulating valve 7 is formed of a circular gas permeable sheet 8 disposed on the upper surface of the communication hole 3d, and a rubber formed in a ring shape and disposed on the gas permeable sheet 8. The valve body 9 and a cap 10 having a hole 10a communicating with the outside, and the protrusion 3e provided integrally with the terminal plate 3 are crimped to hold the valve body 9 in a compressed state. The pressure regulating valve 7 urged in a direction that is normally closed is configured.

  In FIG. 2, 1b is an anode electrode portion of the element 1, 1d is a recess provided by partially recessing the anode electrode portion 1b, and the recess 1d includes at least the pressure regulating valve 7. It is provided in a portion in contact with the communication hole 3d provided in the joined terminal plate 3, and the amount of depression is about 0.5 to 6.0 mm.

  The pressure regulating valve 7 provided in the electric double layer capacitor according to the present embodiment configured as described above is a self-returning type for releasing the pressure to the outside when the internal pressure of the capacitor exceeds a predetermined pressure. The gas generated inside the capacitor can be released to prevent the pressure inside the capacitor from rising, and the pressure regulating valve 7 can be restored to the state before the operation after the operation to maintain the airtightness inside the capacitor. Therefore, there is no abnormality in the external appearance of the capacitor, and the characteristics can be maintained.

  Further, the pressure regulating valve 7 is provided with a gas permeable sheet 8 made of a material which prevents the permeation of the driving electrolyte and permeates the gas generated inside the capacitor to the outside, thereby driving the pressure regulating valve 7. The electrolytic solution does not adhere to the valve body 9 and impair the function of the pressure regulating valve 7, and the leakage of the driving electrolytic solution to the outside of the capacitor can be prevented via the pressure regulating valve 7.

  In addition, a recess 1d is formed in which a part of the anode electrode portion 1b of the element 1 in contact with the communication hole 3d provided in the terminal plate 3 to which the pressure regulating valve 7 is coupled is recessed so as not to contact the communication hole 3d. Since the driving electrolyte impregnated in the element 1 can be significantly reduced from entering the communication hole 3d by the provided configuration, the driving electrolyte is stuck in a ball shape in the communication hole 3d. This prevents the liquid pool phenomenon and, as a result, the effect that the driving electrolyte does not leak to the outside can be obtained, so that the pressure regulating valve 7 with improved reliability can be realized. Thus, the electrical double layer capacitor with higher reliability can be provided.

  In the present embodiment, the terminal plate 3 is provided with an electrolyte injection hole (not shown) and the hole is closed with the rubber plug 6 as an example. However, the present invention is not limited to this. Instead, the rubber plug 6 can be eliminated by using the communication hole 3d provided in the terminal plate 3 to which the pressure regulating valve 7 is coupled as the electrolyte injection hole.

  Further, the rubber valve body 9 constituting the pressure regulating valve 7 is not limited to the ring shape shown in FIG. 2, and may be, for example, a bottomed shape. It is.

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

  3A to 3C are a plan view, a front sectional view, and a bottom view showing a configuration of an electric double layer capacitor as an example of the capacitor according to the second embodiment of the present invention. In FIG. 11a indicates a hollow portion formed in the element 11. The element 11 has a pair of positive and negative electrodes in which a polarizable electrode layer is formed except for one end on a current collector made of an aluminum foil. The elements 11 are configured such that each polarizable electrode layer-unformed portion of the positive and negative electrodes is exposed to the opposing end face by winding with a separator interposed between them (not shown). The anode electrode part 11b and the cathode electrode part 11c are respectively taken out from both end faces (vertical direction in FIG. 3).

  Reference numeral 12 denotes an aluminum bottomed cylindrical metal case containing the element 11 together with a driving electrolyte solution (not shown), and a cathode electrode portion provided on one end face of the element 11 inserted into the metal case 12. The element 11c is mechanically and electrically joined by laser welding (welding mark 12b) to an element joint 12a formed so as to partially protrude from the inner bottom surface of the metal case 12. One electrode (negative electrode) is taken out from the metal case 12.

  Reference numeral 13 denotes an aluminum terminal plate, 13a denotes an element joint portion provided on the inner surface of the terminal plate 13 so as to be partially convex, and 13d denotes a protruding amount of the element joint portion 13a. Then, the element joint portion 13a of the terminal plate 13 is brought into contact with the anode electrode portion 11b provided on the other end face of the element 11 to be crushed (displacement amount 11d), and laser welding (weld trace 13b) is performed in this state. Thus, the other electrode (positive electrode) of the element 11 is taken out from the terminal plate 13 by mechanically and electrically joining.

  14 is disposed between the outer peripheral surface of the terminal plate 13 and the inner peripheral surface of the metal case 12 and is an L-shaped annular insulating member that insulates the two, and 15 is disposed on the peripheral edge of the upper surface of the terminal plate 13. A sealing rubber 16 that is compressed and sealed by curling the open end of the metal case 12, and 16 is a pressure regulating valve that is mounted so as to close the communication hole 13 c provided in the terminal plate 13.

  The electric double layer capacitor according to the present embodiment configured as described above is in contact with the element joint 13a rather than the protruding amount 13d of the element joint 13a provided on the terminal plate 13 to which the pressure regulating valve 16 is coupled. A predetermined gap is ensured between the communication hole 13c provided in the terminal plate 13 and the anode electrode part 11b of the element 11 by the configuration in which the displacement amount 11d of the anode electrode part 11b of the element 11 to be crushed is reduced. Therefore, the probability that the driving electrolyte impregnated in the element 11 wraps around the communication hole 13c can be greatly reduced, thereby preventing the liquid pool phenomenon and improving the reliability. The intended pressure regulating valve 16 can be realized, and the electrical double layer capacitor with higher reliability can be provided.

  In the present embodiment, the terminal plate 13 is described with an example in which one communication hole 13c is provided. However, as in the first embodiment, the terminal plate is provided with two communication holes. In this case, the same effect can be obtained by closing the remaining one communication hole with a rubber plug as in the first embodiment.

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

  In the present embodiment, the configuration of the pressure regulating valve used in the electric double layer capacitor described in the first embodiment with reference to FIG. 2 is partially different, and other configurations are the same as in the embodiment. The same reference numerals are given to the same parts and the detailed description thereof is omitted, and only different parts will be described below with reference to the drawings.

  FIG. 4 is a cross-sectional view showing a configuration of a pressure regulating valve used in an electric double layer capacitor as an example of a capacitor according to Embodiment 3 of the present invention. In FIG. 4, 8 is a circular gas permeable sheet. The gas permeable sheet 8 is disposed so as to close the communication hole 3d provided in the terminal plate 3 from the inner surface side (element bonding surface side).

  The electric double layer capacitor according to the present embodiment configured as described above has a portion of the element 1 in contact with the communication hole 3d provided in the terminal plate 3 to which the pressure regulating valve 7 is coupled, as in the first embodiment. With the configuration in which the recess 1d is provided so that the anode electrode portion 1b is recessed so as not to come into contact with the communication hole 3d, the probability that the driving electrolyte impregnated in the element 1 goes into the communication hole 3d can be greatly reduced. In addition to the possibility, the configuration in which the gas permeable sheet 8 is disposed on the inner surface side (element bonding surface side) of the communication hole 3d can prevent the driving electrolyte from entering the communication hole 3d. As a result, there is no occurrence of a liquid pool phenomenon, and an exceptional effect is achieved that an extremely reliable electric double layer capacitor can be provided.

(Embodiment 4)
The fourth aspect of the present invention will be described below with reference to the fourth embodiment.

  In the present embodiment, the configuration of the pressure regulating valve used in the electric double layer capacitor described in the first embodiment with reference to FIG. 2 is partially different, and other configurations are the same as in the embodiment. The same reference numerals are given to the same parts and the detailed description thereof is omitted, and only different parts will be described below with reference to the drawings.

  FIG. 5 is a cross-sectional view showing a configuration of a pressure regulating valve used for an electric double layer capacitor as an example of a capacitor according to Embodiment 4 of the present invention. In FIG. This is a roughening treatment applied to the inner peripheral surface of the communication hole 3d provided in the terminal plate 3 and a part of the inner surface side of the terminal plate 3 connected to the communication hole 3d. For example, the surface is chemically etched and roughened by means such as application of an acidic solution or immersion in an acidic solution, or physical roughening by means of blasting or the like.

  The electric double layer capacitor according to the present embodiment configured as described above includes the inner peripheral surface of the communication hole 3d provided in the terminal plate 3 to which the pressure regulating valve 7 is coupled, and the terminal plate 3 connected to the communication hole 3d. Due to the configuration in which the surface roughening treatment 3f is applied to a part of the inner surface side, the portion subjected to the surface roughening treatment 3f has improved wettability, so even when the driving electrolyte enters the communication hole 3d. Thus, it is possible to make it difficult to generate a liquid pool phenomenon in which the driving electrolyte is stuck in a ball shape on the inner wall of the communication hole 3d.

(Embodiment 5)
Hereinafter, the invention according to claim 5 of the present invention will be described with reference to the fifth embodiment.

  In the present embodiment, the configuration of the element used in the electric double layer capacitor described in the first embodiment with reference to FIG. 1 is partially different. Other configurations are different from those in the first embodiment. For the same reason, the same reference numerals are given to the same parts, and detailed description thereof is omitted, and only different parts will be described below with reference to the drawings.

  FIG. 6 is a cross-sectional view showing a configuration of a pressure regulating valve used in an electric double layer capacitor as an example of a capacitor according to Embodiment 5 of the present invention. In FIG. Reference numeral 1e denotes a protruding portion provided by partially protruding the anode electrode portion 1b. The protruding portion 1e is configured to enter the inside of the communication hole 3d provided in the terminal plate 3.

  In the electric double layer capacitor according to the present embodiment configured as described above, the protruding portion 1e that enters the communication hole 3d provided in the terminal plate 3 to which the pressure regulating valve 7 is coupled is provided in the anode electrode portion 1b of the element 1. Due to the above structure, the current collector of the anode electrode portion 1b constituting the protruding portion 1e has good wettability because the surface is roughened by the etching process, and the protruding portion 1e is used for driving. Even if the electrolytic solution wraps around, it immediately enters the inside of the element 1, and as a result, it is possible to prevent the occurrence of a liquid pool phenomenon in which the driving electrolytic solution is stuck in the communication hole 3d. Thus, a highly reliable electric double layer capacitor can be provided.

  The electric double layer capacitor according to the present embodiment can be subjected to the roughening treatment 3f provided in the communication hole 3d of the terminal plate 3 of the electric double layer capacitor according to the fourth embodiment. By adopting the configuration, it is possible to provide a further highly reliable electric double layer capacitor.

  In addition, in the electric double layer capacitors of the first to fifth embodiments, the inner peripheral surfaces of the communication holes 3d and 13c provided in the terminal plates 3 and 13 and a part of the front and back surfaces of the terminal plates 3 and 13 connected thereto. By providing an insulating layer made of modified polypropylene or the like, it becomes possible to increase wettability and make it difficult for the driving electrolyte to stick, and the effects of the present invention can be further enhanced.

  The capacitor according to the present invention has an effect of eliminating the leakage of the driving electrolyte and exhibiting high reliability, and is useful in the field of automobiles and the like that require a particularly severe use environment.

(A) The top view which showed the structure of the electric double layer capacitor by Embodiment 1 of this invention, (b) The front sectional drawing, (c) The bottom view Sectional drawing which showed the structure of the pressure regulating valve provided in the same electric double layer capacitor (A) The top view which showed the structure of the electrical double layer capacitor by Embodiment 2 of this invention, (b) The front sectional drawing, (c) The bottom view Sectional drawing which showed the structure of the pressure regulating valve used for the electric double layer capacitor by Embodiment 3 of this invention Sectional drawing which showed the structure of the pressure regulating valve used for the electric double layer capacitor by Embodiment 4 of this invention Sectional drawing which showed the structure of the pressure regulating valve used for the electric double layer capacitor by Embodiment 5 of this invention Sectional view showing the configuration of a conventional electric double layer capacitor Sectional drawing which showed the structure of the pressure regulating valve provided in the same electric double layer capacitor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 Element 1a, 11a Hollow part 1b, 11b Anode electrode part 1c, 11c Cathode electrode part 1d Depression 1e Protrusion part 2, 12 Metal case 2a, 12a, 3b, 13a Element junction part 2b, 12b, 3c, 13b Weld trace 3, 13 Terminal plate 3a, 3e Protrusion 3d, 13c Communication hole 3f Roughening treatment 4, 14 Insulating member 5, 15 Sealing rubber 6 Rubber plug 7, 16 Pressure regulating valve 8 Gas permeable sheet 9 Valve body 10 Cap 10a Hole 11d Displacement of anode electrode part 13d Projection of element joint

Claims (6)

A pair of positive and negative electrodes in which a polarizable electrode layer is formed except for one end on a current collector made of a metal foil are stacked in opposite directions, and wound with a separator interposed therebetween, whereby each of the positive and negative electrodes An element configured to form a pair of electrode take-out portions by exposing the non-polarized electrode layer-formed portions to opposing end surfaces, and housing the device together with a driving electrolyte, and one electrode of the device A bottomed cylindrical metal case joined to the inner bottom surface, a terminal plate in which the other electrode of the element is joined to the inner surface to seal the opening of the metal case, and a communication hole provided in the terminal plate In the capacitor consisting of a pressure regulating valve coupled to the upper surface side of the terminal plate so as to block, at least by partially denting the electrode portion of the element in contact with the communication hole provided in the terminal plate, The electrode part of the element is a communication hole Capacitors to avoid contact. A pair of positive and negative electrodes in which a polarizable electrode layer is formed except for one end on a current collector made of a metal foil are stacked in opposite directions, and wound with a separator interposed therebetween, whereby each of the positive and negative electrodes An element configured to form a pair of electrode take-out portions by exposing the non-polarized electrode layer-formed portions to opposing end surfaces, and housing the device together with a driving electrolyte, and one electrode of the device A bottomed cylindrical metal case joined to the inner bottom surface, a terminal plate in which the other electrode of the element is joined to the inner surface to seal the opening of the metal case, and a communication hole provided in the terminal plate In a capacitor comprising a pressure regulating valve coupled to the upper surface side of the terminal plate so as to close the terminal plate, an element joint portion formed in a partially convex shape is provided on the inner surface of the terminal plate, and the terminal plate of this element joint portion This element contact is more than the amount of protrusion from the inner surface. Capacitors displacement of the electrode portion of the element to be crushed is set to be smaller by parts. The capacitor according to claim 1, wherein a gas permeable sheet is disposed on an inner surface side of the terminal plate so as to close a communication hole provided in the terminal plate. A pair of positive and negative electrodes in which a polarizable electrode layer is formed except for one end on a current collector made of a metal foil are stacked in opposite directions, and wound with a separator interposed therebetween, whereby each of the positive and negative electrodes An element configured to form a pair of electrode take-out portions by exposing the non-polarized electrode layer-formed portions to opposing end surfaces, and housing the device together with a driving electrolyte, and one electrode of the device A bottomed cylindrical metal case joined to the inner bottom surface, a terminal plate in which the other electrode of the element is joined to the inner surface to seal the opening of the metal case, and a communication hole provided in the terminal plate In a capacitor comprising a pressure regulating valve coupled to the upper surface side of the terminal plate so as to block the inner peripheral surface of the communication hole provided in the terminal plate, and a part of the inner surface side of the terminal plate connected to the communication hole Capacitor with roughened surface. A pair of positive and negative electrodes in which a polarizable electrode layer is formed except for one end on a current collector made of a metal foil are stacked in opposite directions, and wound with a separator interposed therebetween, whereby each of the positive and negative electrodes An element configured to form a pair of electrode take-out portions by exposing the non-polarized electrode layer-formed portions to opposing end surfaces, and housing the device together with a driving electrolyte, and one electrode of the device A bottomed cylindrical metal case joined to the inner bottom surface, a terminal plate in which the other electrode of the element is joined to the inner surface to seal the opening of the metal case, and a communication hole provided in the terminal plate In a capacitor composed of a pressure regulating valve coupled to the upper surface side of the terminal plate so as to block the electrode, the electrode portion of the element in contact with the communication hole provided in the terminal plate is partially protruded, and this protrusion is made Enter the inside of the communication hole. Maseru way the capacitor. The capacitor as described in any one of Claims 1-5 which provided the insulating layer in the inner peripheral surface of the communicating hole provided in the terminal board, and a part of front and back of the terminal board connected to this.

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