JP2005032850A - Electric double layer capacitor and its producing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an electric double layer capacitor comprising a heat seal part for sealing a capacitor body and electrolyte hermetically in a case formed of a multilayer resin film having a metallic intermediate layer in which a heat seal part having a hard-to-strip welding surface can be attained for sealing the case hermetically. <P>SOLUTION: The electric double layer capacitor comprises a capacitor body consisting of a polarizable electrode, a separator and a collector electrode, and a heat seal part for sealing the capacitor body and electrolyte hermetically in a case formed of a multilayer resin film having a metallic intermediate layer wherein irregular pressure print pattern 34a is imparted to the heat seal part 13 of the case 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric double layer capacitor and a method for manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art In recent years, attention has been focused on application technologies for electric double layer capacitors that can be rapidly charged and have a long charge / discharge cycle life as various power storage devices.
[0003]
An electric double layer capacitor is disclosed that includes a capacitor body composed of a polarizable electrode, a separator, and a collecting electrode, and a container that seals the capacitor body together with an electrolyte (see Patent Document 1).
[0004]
The container is made from a laminated film of resin with a metal intermediate layer, and the periphery of the recess (space) that accommodates the capacitor body together with the electrolyte is sealed by heat-welding (heat-sealing) the joint allowance of the overlapping laminated films The heat seal part to perform is provided.
[0005]
The heat sealer is not related to the electric double layer capacitor and the manufacturing method thereof, but is used to bind both ends of the flat cord wound around the package by thermal welding (refer to Patent Document 2), and a plurality of waterproof sheets by thermal welding. An apparatus for joining (see Patent Document 3) is disclosed.
[0006]
[Patent Document 1] JP 2000-299168 [Patent Document 2] JP 11-268713 [Patent Document 3] JP 10-128850 A
[Problems to be solved by the invention]
In Patent Document 1, the bonding allowance of the laminated film overlapping the periphery of the concave portion is that the resin on the surface layer is thermally welded to a uniform surface pressure by the flat heating surface of the heat sealer. In order to secure the welding strength, it is required to take a large allowance for the laminated film. When peeling enters a part of the welded surface, a tendency to progress at a stretch on the welded surface having a smooth weld strength is observed.
[0008]
An object of the present invention is to provide an effective means for improving such problems.
[0009]
[Means for Solving the Problems]
1st invention is a heat seal part which seals a capacitor main body with electrolyte solution in a container formed from a capacitor main body composed of a polarizable electrode, a separator, and a collecting electrode, and a laminated film of a resin having a metal intermediate layer In the electric double layer capacitor, the heat seal part of the container is provided with an uneven impression pattern.
[0010]
According to a second aspect of the invention, in the electric double layer capacitor according to the first aspect of the invention, the coining pattern is formed in a grid-like unevenness.
[0011]
According to a third aspect of the invention, in the electric double layer capacitor according to the first aspect of the invention, the impression pattern is processed from both sides of the heat seal portion.
[0012]
A fourth invention comprises a step of composing a capacitor body from a polarizable electrode, a separator, and a collecting electrode, and a step of sealing the capacitor body together with an electrolyte in a container formed from a laminated film of a resin having a metal intermediate layer. In the method of manufacturing an electric double layer capacitor, the step of sealing the capacitor body together with the electrolyte in a container formed of a laminated film of a resin having a metal intermediate layer has unevenness for adding a coining pattern on the heating surface. It has the process of sealing a container with the heat sealer which has.
[0013]
According to a fifth aspect of the invention, in the electric double layer capacitor according to the fourth aspect of the invention, the heat sealer is provided with a pair of heating surfaces having projections and depressions for applying a coining pattern so as to be able to contact and separate from each other in one direction. To do.
[0014]
【The invention's effect】
In the first invention, the uneven surface of the heat seal portion is not flat and the uneven surface of the coin seal pattern is generated due to the uneven impression pattern, so that the welding area can be increased without changing the plane area of the heat weld portion. Therefore, it is possible to effectively secure the welding strength. Since the welding strength is not smooth over the entire welded surface and is strengthened by unevenness, the progress of peeling is prevented by the unevenness, and the welded surface is not enlarged at a stretch. Therefore, a heat seal part in which the welded surface is difficult to peel off is obtained for sealing the container, and the durability and reliability of the electric double layer capacitor can be improved.
[0015]
In the second invention, since the unevenness of the coined pattern extends obliquely in the width direction of the heat seal portion like a fringe (wire), the oblique uneven surface stripe becomes longer than the width of the heat seal portion. Since the welding area is efficiently expanded and the oblique uneven lines overlap the width direction of the heat seal portion in parallel, the protection against peeling also works in multiple ways.
[0016]
In the third invention, by processing the coined pattern from both sides, a cross-sectional shape in which irregularities on both sides are complicated is obtained, and the welding area and the welding strength can be effectively increased.
[0017]
In the fourth aspect of the invention, by providing a step of sealing the container with a heat sealer having unevenness on the heating surface for adding a coining pattern, a heat seal portion that is difficult to peel off the welded surface for sealing the container is obtained, which is durable In addition, an electric double layer capacitor with good reliability can be efficiently produced.
[0018]
In the fifth aspect of the invention, the heat of the heat sealer that causes the heating surface having a pair of coining patterns to contact and separate from each other in one direction is a heat that is difficult to peel off the welding surface such that the unevenness on one side and the unevenness on the one side are complicated. An electric double layer capacitor having a seal portion and excellent in durability and reliability can be efficiently produced.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
An example of an electric double layer capacitor will be described with reference to FIG. Reference numeral 10 denotes a container for accommodating the capacitor body 20 together with an electrolytic solution (organic electrolytic solution), and a pair of terminals 21 (electrodes) are drawn out. Each terminal 21a, 21b is formed in a short shape from light weight aluminum having a small electric resistance.
[0020]
The capacitor body 20 is composed of a rectangular positive electrode body and a negative electrode body, and a separator (a porous film made of paper or the like) interposed therebetween to form a predetermined laminate. The positive electrode body and the negative electrode body are composed of a collector electrode and polarizable electrodes (activated carbon electrodes) on both sides thereof. These collector electrodes are made of a rectangular metal foil (for example, an aluminum foil), and a strip-shaped lead portion is integrally formed on one side of the rectangular plane. The same polarity of each lead part is bundled, and the terminal 21 corresponding to polarity is joined to this binding part.
[0021]
The container 10 is composed of two container parts (a bottom side part 10a and a lid side part 10b) that are drawn into the same shape from a laminated film of a resin including a metal intermediate layer. , 11b (which is a convex portion on the outer surface of the container 10) forms a housing portion for the laminate 20 between the bottom portion 10a and the lid portion 10b. 12a to 12d are flanges that form mating surfaces (joining allowances) around the recesses 11a and 11b.
[0022]
The laminated body 20 is housed inside the bottom side portion 10a, and the lid side portion 10b is covered thereon. Around the recesses 11a and 11b (flanges 12a to 12d), the three sides 12b to 12d excluding the one side 12a from which the pair of terminals 21 (part thereof) are drawn are thermally welded. The container 10 can be opened at one side 12a from which a pair of terminals 21 protrudes, and after the electrolyte is injected through the opening and the impregnation and electrolytic purification of the electrolyte are completed, the excess electrolyte is extracted and the remaining The openable side 12a is thermally welded.
[0023]
The bottom-side portion 10a and the lid-side portion 10b are formed using a resin laminated film including a metal intermediate layer as a raw material. The laminated film serving as the raw material is sandwiched between an aluminum foil intermediate layer 41 and this. It is created in a three-layer structure with resin surface layers 42 and 43. The surface layer 42 constituting the outer surface of the container 10 is formed of PET (polyethylene terephthalate) or nylon, and the surface layer 43 constituting the inner surface of the container is formed of PP (polypropylene) or the like (see FIG. 4).
[0024]
FIG. 2 shows a main part configuration of a heat sealer 30 that processes sealing (thermal welding) of three sides 12b to 12d excluding one side 12a from which a pair of terminals 11 (part thereof) is drawn. Heaters 31 and 32 are arranged above and below. The heater 31 is formed with a recess 32 that can receive the recess 11a (outer surface protrusion) of the bottom portion 10a. The bottom side portion 10a is positioned in the concave portion 32 of the heater 31, the laminated body 20 is housed inside, and the lid side portion 10b is covered from above. The pair of heaters 31 and 32 are provided with a heating surface 34 corresponding to the joining margin of the three sides 12b to 12d of the container excluding the one side 12a from which the pair of terminals 11 protrudes.
[0025]
An uneven impression pattern 34 a is provided on each heating surface 34. The impression pattern 34a is set to have a shape in which the unevenness extends obliquely in the width direction of the joining margin like a crease (line) (see FIG. 3). The heater 31 is fixed with the heating surface 34 facing upward, and the heater 32 is connected to the rod 35 of an elevating device (not shown) with the heating surface 34 facing downward. The pair of heating surfaces 34 are configured to be able to contact and separate in the vertical direction by operation of the lifting device, and by heating the joining margin sandwiched between them, the three sides 12b to 12d are thermally welded as shown in FIG. The unevenness of the coin pattern 34a is processed from both sides in the portion 13 (heat seal portion).
[0026]
The uneven surface of the heat seal portion 13 that seals the three sides 12b to 12d of the container 10 is not flat due to the uneven impression pattern 34a, and unevenness of the impression pattern 34a is generated as shown in FIG. 41 also has the unevenness of the coined pattern 34a), so that the welding area can be increased without changing the plane area of the heat welding portion 13, and the welding strength can be effectively secured. The weld strength is not smooth over the entire weld surface, and the portion with high surface pressure due to the unevenness is strengthened. Therefore, the progress of peeling is prevented by the unevenness, and the weld surface is not enlarged at a stretch. Therefore, the heat seal part 13 in which the welded surface is difficult to peel off for sealing the container 10 is obtained, and the durability and reliability of the electric double layer capacitor can be greatly enhanced.
[0027]
About the unevenness | corrugation of the coin pattern 34a, since the width direction of the heat seal part 13 is extended diagonally like a crease (line), the diagonal uneven | corrugated line | wire becomes longer than the width | variety of the heat seal part 13, and it welds The area is efficiently enlarged, and the oblique irregular stripes overlap the width direction of the heat seal portion 13 in parallel, so that the prevention of peeling works in multiple ways.
[0028]
Since the coined pattern 34a is processed from both sides of the container 10 by the heat sealer 30, a cross-sectional shape in which irregularities on both sides are complicated is obtained, and when the irregularities of the coined pattern 34a on both sides are set in phase as shown in FIG. It is also possible to promote an increase in welding depth (welding strength). Of course, as for the unevenness | corrugation of both sides, you may set an oblique line | wire to a reverse direction so that the coined pattern 34a of the heat seal part 13 may cross | intersect.
[0029]
The container 10 is thermally welded on three sides 12b to 12d except for one side 12a from which a pair of terminals 11 (a part thereof) protrudes, and the remaining one side 12a is thermally welded after the electrolytic impregnation and electrolytic purification processes. The sealing portion is not described in detail, but in order to increase the welding strength, it is desirable to provide the coined pattern 34a by the same processing as the three sides 12b to 12d.
[0030]
About the manufacturing method of an electric double layer capacitor, since it has the process of processing the sealing of the container 10 with a heat sealer having irregularities for adding the coin pattern 34a on the heating surface, the heat seal portion is less likely to be peeled off, High-quality products (electric double layer capacitors) with excellent reliability can be produced efficiently.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating the composition of an electric double layer capacitor.
FIG. 2 is a perspective view of a main part of a heat sealer.
FIGS. 3A and 3B are a plan view and a side view showing a partial heating surface on the upper side and FIG. 3B on the lower side, respectively.
FIG. 4 is a cross-sectional view of a heat seal part.
FIG. 5 is an explanatory diagram of a sealing process.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Container 10a Bottom side part 10b Cover side part 11a, 11b Recessed part 12a-12b Flange 13 Heat seal part 20 Capacitor main body (laminated body)
21 (21a, 21b) Terminal 30 Heat sealer 31, 32 Heater 34 Heating surface 34a Imprint pattern

Claims (5)

A capacitor body composed of a polarizable electrode, a separator, and a collector electrode; and a heat seal portion that seals the capacitor body together with an electrolyte in a container formed of a laminated film of a resin having a metal intermediate layer. An electric double layer capacitor, characterized in that the heat seal portion of the container is provided with an uneven impression pattern in the multilayer capacitor. 2. The electric double layer capacitor according to claim 1, wherein the coin pattern is formed in a grid-like unevenness. The electric double layer capacitor according to claim 1, wherein the coin pattern is processed from both sides of the heat seal portion. An electric double layer comprising: forming a capacitor body from a polarizable electrode, a separator, and a collecting electrode; and sealing the capacitor body together with an electrolyte in a container formed from a laminated film of a resin having a metal intermediate layer In the method of manufacturing a capacitor, the process of sealing the capacitor body together with the electrolyte in a container formed from a laminated film of a resin having a metal intermediate layer is performed by sealing the container with a heat sealer having irregularities on the heating surface for adding a coined pattern. A process for producing an electric double layer capacitor comprising the step of: 5. The method of manufacturing an electric double layer capacitor according to claim 4, wherein the heat sealer includes a pair of heating surfaces having projections and depressions for applying a coining pattern so as to be able to contact and separate from each other in one direction.

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