JP5585153B2 - Multilayer electric double layer capacitor - Google Patents

Description

  The present invention relates to a multilayer electric double layer capacitor, and more particularly to a clamping structure of a bipolar multilayer electric double layer capacitor.

  Current storage devices include secondary batteries using electrochemical reactions, electric double layer capacitors using ion adsorption, capacitors using dielectric phenomena, and the like. Among them, the electric double layer capacitor is attracting attention because it has low energy density but does not contain heavy metals, so it has a low environmental load, is maintenance-free, and has a long life.

  In recent years, electric double layer capacitors are expected to be applied in various fields due to energy saving or heightened awareness of the environment. For this reason, there is a demand for higher energy density. Development is underway.

  The voltage of the capacitor cell is limited by the decomposition voltage of the electrolytic solution, and usually, a large number of capacitors used at a decomposition voltage or less are connected in series or in parallel to satisfy the required load capacity.

  A multi-layered electric double layer capacitor is obtained by stacking a large number of single cells as capacitor cells in series and packaging them as a unit. Such stacking is advantageous in terms of energy density because wiring is reduced and dead space is eliminated as compared with the case where a large number of capacitors each having a single cell in one package are connected in series or in parallel. It becomes.

  FIG. 7 shows a cross section of an example of the structure of a conventional multilayer electric double layer capacitor (hereinafter referred to as a capacitor), and FIG. 8 shows an example of a conventional capacitor clamping structure. As shown in FIGS. 7 and 8, the capacitor 100 is formed by stacking capacitor cells (hereinafter simply referred to as cells) 13 corresponding to a necessary voltage, end plates 118 and 119, insulating spacers 121, and metal countersunk screws 122. , 123 is fixed.

  More specifically, a side surface of a multi-layered body (capacitor unit body) 15 formed by stacking a plurality of (three in the illustrated example) cells 13 via a current collector 14 made of a metal substrate is sandwiched between end plates 118 and 119. The multi-layered product 15 is fastened by the end plates 118 and 119 by screwing the countersunk screws 122 and 123 into the insulating spacer 121 arranged between the end plates 118 and 119. Further, plate-like current collecting terminals 116 and 117 are respectively arranged between the end plates 118 and 119 and the cell 13 at the outermost portion, and a part thereof is taken out of the cell 13 to serve as an electrical outlet.

  The cell 13 is a minimum unit of the capacitor, and includes a separator 11 that can transmit ions, and flat activated carbon electrodes 12 and 12 that are disposed in contact with both side surfaces of the separator 11.

  A frame-shaped packing 120 is disposed on the outer peripheral portions of the activated carbon electrode 12 and the current collector 14 so as to prevent the internal electrolyte from leaking out. The packing 120 also serves as insulation between the stacked layers.

  The insulating spacer 121 is made of resin and is a cylindrical body with both ends screwed.

  Capacitor 100 is provided with holes for communicating end plates 118 and 119 on both sides, current collecting terminals 116 and 117 and packing 120 in the stacking direction, and insulating spacer 121 is disposed in a space formed by the holes, and both end portions thereof are formed. A tightening structure 130 is configured to be tightened with countersunk screws 122 and 123 from the end plates 118 and 119 side. As a result, the capacitor 100 maintains a sealed structure.

  An electrolytic solution is injected into the capacitor 100, and the outer periphery of the capacitor 100 is covered with an aluminum laminate film 24 so as to be shielded from outside air. The aluminum laminate film 24 is a film obtained by laminating a metal aluminum foil with polypropylene, polyethylene, or the like.

  By the way, the charging energy of the capacitor described above is determined by the capacitance of the electrode which is a constituent member thereof, and development of a high-capacity electrode is being promoted. As an electrode material expected to have a high capacity, activated carbon obtained by alkali activation of a graphitizable carbon material has been proposed. However, an electrode made of this activated carbon has the property of expanding in the direction of the electric field during charging and discharging. Here, the capacitor 100 described above has a structure in which the insulating spacer 121 and the countersunk screws 122 and 123 regulate the thickness in the stacking direction of the cells 13 in the multi-layered body 15 and do not allow expansion. For this reason, stress during expansion of the electrode concentrates on the insulating spacer 121, and if this stress becomes excessive, the spacer 121 may be mechanically damaged. Therefore, a structure that mechanically allows the electrode to expand is required for the capacitor structure.

  Therefore, various capacitors that allow such expansion in the stacking direction have been developed. For example, Patent Document 1 discloses a multilayer electric double layer capacitor having a structure in which a spring receiver is fitted in the bolt insertion holes of both end plates, a spring is disposed therein, and the bolt is screwed into a spacer via the spring. .

JP 2009-71088 A (see paragraphs [0036] to [0042], [FIG. 4], [FIG. 5], etc.)

  However, in the multilayer electric double layer capacitor described in Patent Document 1, the expansion amount (spring expansion / contraction amount) that allows expansion in the stacking direction of the multi-layered body depends on the size (depth) of the through hole of the end plate. If the size of the through hole is limited, stress may concentrate on the spacer and break the spacer. Although it is conceivable that the size of the spring receiver (the size of the through hole in the depth direction) is made larger than that of the through hole, the spring receiver and the cell cannot be insulated as they are because they are metal parts. In addition, it is conceivable to increase the thickness of the spring plate by increasing the thickness of the end plate. However, there is a possibility that the weight / energy density may be reduced due to the increase in the deposition. Furthermore, although it can be considered that the head of the bolt protrudes outward from the side surface of the end plate, the energy density may be reduced accordingly.

  Accordingly, the present invention has been proposed in view of the above-described problems, and the amount of expansion that can be allowed to expand in the stacking direction of the cells in the multi-layered body can be made larger than the thickness of the end plate, and the tightening force can be increased. It is an object to provide a multilayer electric double layer capacitor that can be obtained.

The multilayer electric double layer capacitor according to the first invention for solving the above-described problem is:
A multi-layered body in which a plurality of capacitor cells are stacked via a conductive substrate;
Two end plates sandwiching the multi-laminate,
A plurality of packings interposed between the adjacent conductive substrates and along the outer periphery of the conductive substrate; and
An insulating spacer inserted from the outside of one of the end plates, penetrating the packing in the stacking direction of the capacitor cells, and locked to the one end plate;
From the outside of the other end plate, a bolt in which a shaft body is inserted into the insulating spacer in the stacking direction of the plurality of capacitor cells, and a head is locked to the other end plate ;
An elastic body inserted into the shaft of the bolt and biased in the stacking direction of the plurality of capacitor cells;
First elastic body locking means provided on the insulating spacer and locking one end of the elastic body;
A second elastic body locking means provided on the bolt and locking the other end of the elastic body ;
A fixing means for fixing the insulating spacer and the one end plate ;
The elastic body, the first elastic body locking means and the second elastic body locking means are inserted into the insulating spacer,
The insulating spacer includes a cylindrical portion and a jaw portion that is provided at one end of the cylindrical portion and can be locked to the one end plate;
The jaw portion of the insulating spacer is shaped to fit into the through hole of the one end plate,
The fixing means is an adhesive applied to the outer peripheral portion of the jaw portion and the through hole, or a screw portion and an end provided on the outer peripheral portion of the cylindrical portion in the vicinity of the jaw portion of the insulating spacer. A screw portion provided in the through hole of the plate and screwed into the screw portion of the insulating spacer .

The multilayer electric double layer capacitor according to the second invention for solving the above-described problem is:
A multilayer electric double layer capacitor according to a first invention,
The first elastic body locking means includes a small diameter portion provided at the other end of the cylindrical portion, or the small diameter portion of the cylindrical portion and a washer disposed on the small diameter portion. And

The multilayer electric double layer capacitor according to the third invention for solving the above-described problem is:
A stacked electric double layer capacitor according to the second invention,
The second elastic body locking means is a nut screwed into a threaded portion of the bolt;
The small diameter portion of the cylindrical portion and the nut have the same shape.

According to the multilayer electric double layer capacitor of the present invention, a multi-layered body in which a plurality of capacitor cells are stacked via a conductive base material, two end plates sandwiching the multi-layered body, and the adjacent conductive materials A plurality of packings interposed between the substrates and along the outer periphery of the conductive substrate, and inserted from the outside of one of the end plates, and penetrates the packing in the stacking direction of the plurality of capacitor cells. The shaft is inserted into the insulating spacer in the stacking direction of the plurality of capacitor cells from the outside of the other end plate and the insulating spacer locked to the one end plate. to a bolt head is locked, is inserted into the shaft portion of the bolt, and an elastic body for urging the stacking direction of the plurality of capacitor cells, provided in the insulating spacers, prior to By providing a first elastic body locking means for locking one end portion of the elastic body, and a second elastic body locking means provided on the bolt and for locking the other end portion of the elastic body. The amount of expansion / contraction that the elastic body can expand / contract becomes the distance between the first elastic body locking means and the second elastic body locking means. Thereby, the expansion amount which can permit expansion | swelling of the lamination direction of the cell in a multi-laminate can be made larger than the thickness of an end plate. Further, the multi-layered body is fastened by the end plate using the biasing force of the elastic body, and the fastening force can be obtained.
Since the edge spacer has a cylindrical portion and a jaw portion that is provided at one end of the cylindrical portion and can be locked to one end plate, the insulating spacer can be easily provided with a relatively simple configuration. It can be locked to one end plate.
The jaw of the insulating spacer is shaped to fit into the through-hole of one end plate, preventing the end of the insulating spacer from protruding to the outside of the side surface of the end plate and reducing the energy density. Can be suppressed.
By providing a fixing means for fixing the insulating spacer and one end plate, rotation of the insulating spacer around the axis can be prevented, and assembling workability is improved.

  According to the multilayer electric double layer capacitor of the present invention, the first elastic body locking means is disposed in the small diameter portion provided at the other end of the cylindrical portion, or the small diameter portion of the cylindrical portion and the small diameter portion. By comprising the washer which is made, the one end part of an elastic body can be reliably latched.

  According to the multilayer electric double layer capacitor according to the present invention, the second elastic body locking means is a nut, and the small diameter portion of the cylindrical portion and the nut have the same shape. As a result, the assembly workability is improved.

It is sectional drawing of the capacitor which concerns on 1st embodiment of this invention. It is the figure which showed the clamping structure of the capacitor typically. It is a figure for demonstrating the spacer which a capacitor comprises, Comprising: The plane is shown to Fig.3 (a), the side which notched part was shown to FIG.3 (b), and the lower surface was shown to FIG.3 (c). Show. It is the figure which showed typically the clamping structure of the capacitor which concerns on 2nd embodiment of this invention. It is the figure which showed typically the clamping structure of the capacitor which concerns on 3rd embodiment of this invention. It is a figure for demonstrating the spacer which a capacitor comprises, Comprising: The plane is shown to Fig.6 (a), the side which notched part was shown to FIG.6 (b), and the lower surface was shown to FIG.6 (c). Show. It is sectional drawing of the conventional capacitor. It is the figure which showed typically the fastening structure of the conventional capacitor.

  The capacitor according to the present invention will be specifically described in each embodiment.

[First embodiment]
The capacitor according to the first embodiment of the present invention will be specifically described with reference to FIGS.

  The capacitor according to the present embodiment is replaced with the current collecting terminals 116 and 117, the end plates 118 and 119, the packing 120, and the fastening structure 130 of the conventional capacitor shown in FIGS. The current collecting terminals 16 and 17, the end plates 18 and 19, the packing 20, and the fastening structure 30 shown in FIG. 2 are provided. Thus, the tightening force can be obtained while the expansion amount allowing the expansion in the stacking direction of the three cells 13 in the capacitor 10 is larger than the thickness of the end plate 18. The other configuration is generally the same as the configuration of the conventional capacitor shown in FIG. 7 and described above. Hereinafter, the same members are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

  As shown in FIG. 1, the fastening structure 30 included in the capacitor according to this embodiment includes an insulating spacer 31, a bolt 32, a fastening spring 34, a washer 33, and a hexagon nut 35 (second elastic body locking means). Prepare.

  A plurality of through holes 18 a, 16 a, and 20 a through which the insulating spacer 31 is inserted are formed in one end plate 18, one current collecting terminal 16, and packing 20, respectively. The insulating spacer 31 is inserted into the through hole 18 a of the end plate 18, the through hole 16 a of the current collecting terminal 16, and the through hole 20 a of the packing 20 from the outside of one end plate 18, and is locked to the end plate 18. The The through hole 18a of the end plate 18 is formed in a concave shape that is substantially the same shape as a jaw 31e of an insulating spacer 31 described later, and the end plate 18 is embedded in the jaw 31e of the insulating spacer 31. So that it does not protrude outward from the side surface.

  A plurality of through holes 19 a and 17 a through which the shaft body 32 b of the bolt 32 is inserted are formed in the other end plate 19 and the other current collecting terminal 17, respectively. The shaft body 32b of the bolt 32 is inserted from the outside of the other end plate 19 into the through hole 19a of the other end plate 19 and the through hole 17a of the other current collecting terminal 17, and the head portion 32a of the bolt 32 is Locked to the end plate 19. Further, the shaft 32 b of the bolt 32 is inserted into the insulating spacer 31. In this state, a washer 33 is inserted into the shaft body 32 b of the bolt 32. The head 32a of the bolt 32 has a dish shape. The through hole 19a of the end plate 19 is formed in a concave shape having substantially the same shape as the head portion 32a of the bolt 32, and the head portion 32a of the bolt 32 is embedded in the hole 19a so that the end plate 19 extends outward from the side surface portion. It does not protrude.

  The clamping spring 34 is an elastic body, and is disposed inside the insulating spacer 31 and is inserted into the shaft body 32b portion (shaft portion) of the bolt 32. Thereby, the clamping spring 34 is biased in the stacking direction of the plurality of cells 13.

  As shown in FIGS. 2 and 3, the insulating spacer 31 includes a cylindrical portion 31a, a bottom plate portion (small diameter portion) 31c, and a flange portion 31e. The cylindrical portion 31a has a shaft shape and is provided with a hole portion 31b extending in the axial direction. The jaw part 31e is provided on one end side of the cylindrical part 31a and is formed in a tapered shape. Thereby, the jaw part 31e of the insulating spacer 31 can be fitted into the through hole 18a of the end plate 18 and locked. The hole 31b has a shape into which the washer 33 and the hexagon nut 35 can be inserted, and is formed in substantially the same shape as the hexagon nut 35 in a cross section orthogonal to the axial direction. The bottom plate portion 31c is formed with a smaller diameter than the hole portion 31b, and is provided on the other end side of the cylindrical portion 31a. The bottom plate portion 31c is formed with a hole portion 31d through which the shaft 32b portion of the bolt 32 can be inserted. Therefore, the other end 34 a side of the clamping spring 34 is locked by the bottom plate portion 31 c of the insulating spacer 31 and the washer 33 (first elastic body locking means). The insulating spacer 21 is made of resin.

  The hexagon nut 35 is screwed into the threaded portion of the shaft 32b of the bolt 32. Therefore, the other end 34b side of the clamping spring 34 is locked by the hexagon nut 35 (second elastic body locking means).

  Subsequently, an operation of disposing the current collecting terminals 16 and 17 on both sides of the multi-layered body 15 and assembling the end plates 18 and 19 on the outside will be described with reference to FIGS. 1 and 2.

  First, the packing 20 is disposed around the cell 13 which is a laminate, and these are laminated via the current collector plate 14. End plates 18 and 19 are arranged on both sides of the multi-layered product 15 thus obtained via current collecting terminals 16 and 17.

  Subsequently, the spacer 31 is inserted into the through hole 18 a of the one end plate 18, the through hole 16 a of the one current collecting terminal 16, and the through hole 20 a of the packing 20 from the one end plate 18 side. The shaft body 32b of the bolt 32 is inserted into the through hole 19a of the other end plate 19, the through hole 17a of the other current collecting terminal 17, and the hole 31c of the insulating spacer 31 from the other end plate 19 side.

  Subsequently, a washer 33 and a tightening spring 34 are sequentially inserted into the shaft body 32b of the bolt 32 from one end plate 18 side. Subsequently, the hexagon nut 35 is tightened from the one end plate 18 side to the threaded portion of the shaft 32b of the bolt 32 using a jig or the like.

  In this way, tightening the plurality of cells 13 in the stacking direction by the end plates 18 and 19 using the expansion and contraction force of the tightening spring 34 by simply tightening the hexagon nut 35 to the threaded portion of the shaft 32b of the bolt 32. You can gain power.

  Therefore, according to the capacitor 10 according to the present embodiment, the amount of expansion / contraction that the clamping spring 34 can expand / contract due to the above-described configuration is such that the bottom plate portion 31c and the washer 33 and the hexagon nut 35 of the insulating spacer 31 The distance between. As a result, the expansion amount that allows the expansion in the stacking direction of the cells 13 in the multi-layered body 15 can be made larger than the thickness of the end plate 18. Further, the multi-layered body 15 is fastened by the end plates 18 and 19 using the urging force of the fastening spring 34, and the fastening force can be obtained.

[Second Embodiment]
A capacitor according to the second embodiment of the present invention will be specifically described with reference to FIG.

  The capacitor according to the present embodiment is a capacitor according to the first embodiment described above, and includes a fastening structure that further includes a fixing means for fixing the end plate 18 and the insulating spacer. The other configuration is substantially the same as the configuration of the capacitor of the first embodiment described above. Hereinafter, the same members are denoted by the same reference numerals, and redundant description is appropriately omitted.

  As shown in FIG. 4, the fastening structure 40 included in the capacitor according to the present embodiment fixes the jaw portion 31 e of the insulating spacer 31 and the through hole 18 a of one end plate 18. It further has a fixing means composed of an adhesive 46 such as a cyanoacrylate adhesive such as a registered trademark. The adhesive 46 is applied to the through hole 18 a of one end plate 18 and the outer peripheral portion 31 f of the jaw portion 31 e of the insulating spacer 31. Thereby, the rotation of the insulating spacer 31 around the axis can be prevented, and the assembly workability is improved.

[Third embodiment]
A capacitor according to the third embodiment of the present invention will be specifically described with reference to FIGS.

  The capacitor according to the present embodiment further includes fixing means for fixing the end plate and the insulating spacer in the capacitor according to the first embodiment described above. The other configuration is substantially the same as the configuration of the capacitor of the first embodiment described above. Hereinafter, the same members are denoted by the same reference numerals, and redundant description is appropriately omitted.

  As shown in FIG. 5, the fastening structure 50 included in the capacitor according to the present embodiment fixes the cylindrical portion 51 a of the insulating spacer 51 and the through hole 58 a of one end plate 58. And a fixing means constituted by the threaded portion 51g and the threaded portion 58b of the end plate 58.

  The insulating spacer 51 has substantially the same shape as the insulating spacer 31 included in the fastening structure 30 described above, and includes a cylindrical portion 51a, a hole portion 51b, a bottom plate portion (small diameter portion) 51c, a hole portion 51d, a jaw portion 51e, and a screw portion. 51g. The threaded portion 51g of the insulating spacer 51 is provided on the outer peripheral portion of the cylindrical portion 51a in the vicinity of the jaw portion 51e. The threaded portion 58b of the end plate 58 has a shape that is screwed into the threaded portion 51g of the insulating spacer 51, and is provided in the through hole 58a in the vicinity of the one side surface portion side. Thereby, the rotation of the insulating spacer 51 around the axis can be prevented, and the assembly workability is improved.

  In the above description, a capacitor in which a multi-layer body 15 in which three cells 13 are stacked is sandwiched between two end plates has been described. However, the number of cells 13 is not limited to three, and a multi-layer body in which a plurality of cells 13 are stacked has two ends. It is also possible to apply to a capacitor sandwiched between plates.

  In the above description, the capacitor having the first elastic body locking means including the bottom plate portion (small diameter portion) of the insulating spacer and the washer has been described. However, the capacitor includes the bottom plate portion (small diameter portion) of the insulating spacer. It is also possible to apply to a capacitor having the first elastic body locking means.

  The capacitor according to the present invention can obtain a tightening force with a relatively simple configuration, with an expansion amount that allows expansion in the stacking direction of cells in a multi-layered body larger than the thickness of the end plate. Therefore, it can be used extremely beneficially in the electrical equipment industry and the automobile industry.

DESCRIPTION OF SYMBOLS 10 Capacitor 11 Separator 12 Activated carbon electrode 13 Cell 14 Current collector 15 Multi-layered body 16, 17 Current collection terminal (collection electrode)
18, 19 End plate 20 Packing 24 Aluminum laminate film 30 Tightening structure 31 Insulating spacer 31a Tube portion 31b Hole portion 31c Bottom plate portion (small diameter portion)
31d Hole portion 31e Jaw portion 31f Outer peripheral portion 32 Bolt 32a Head portion 32b Shaft body 33 Washer 34 Tightening spring 35 Hexagon nut 40 Tightening structure 46 Adhesive 50 Tightening structure 51 Insulating spacer 51a Tube portion 51b Hole portion 51c Bottom plate portion 51d Hole portion 51e Jaw part 51g Thread part 58 End plate 58a Hole part 58b Thread part

Claims (3)

A multi-layered body in which a plurality of capacitor cells are stacked via a conductive substrate;
Two end plates sandwiching the multi-laminate,
A plurality of packings interposed between the adjacent conductive substrates and along the outer periphery of the conductive substrate; and
An insulating spacer inserted from the outside of one of the end plates, penetrating the packing in the stacking direction of the capacitor cells, and locked to the one end plate;
From the outside of the other end plate, a bolt in which a shaft body is inserted into the insulating spacer in the stacking direction of the plurality of capacitor cells, and a head is locked to the other end plate ;
An elastic body inserted into the shaft of the bolt and biased in the stacking direction of the plurality of capacitor cells;
First elastic body locking means provided on the insulating spacer and locking one end of the elastic body;
A second elastic body locking means provided on the bolt and locking the other end of the elastic body ;
A fixing means for fixing the insulating spacer and the one end plate ;
The elastic body, the first elastic body locking means and the second elastic body locking means are inserted into the insulating spacer,
The insulating spacer includes a cylindrical portion and a jaw portion that is provided at one end of the cylindrical portion and can be locked to the one end plate;
The jaw portion of the insulating spacer is shaped to fit into the through hole of the one end plate,
The fixing means is an adhesive applied to the outer peripheral portion of the jaw portion and the through hole, or a screw portion and an end provided on the outer peripheral portion of the cylindrical portion in the vicinity of the jaw portion of the insulating spacer. The multilayer electric double layer capacitor, wherein the multilayer electric double layer capacitor is a screw portion provided in the through hole of the plate and screwed into the screw portion of the insulating spacer . The multilayer electric double layer capacitor according to claim 1 ,
The first elastic body locking means includes a small diameter portion provided at the other end of the cylindrical portion, or the small diameter portion of the cylindrical portion and a washer disposed on the small diameter portion. A multilayer electric double layer capacitor. The multilayer electric double layer capacitor according to claim 2 ,
The second elastic body locking means is a nut screwed into a threaded portion of the bolt;
The multilayer electric double layer capacitor, wherein the small diameter portion of the cylindrical portion and the nut have the same shape.

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