JP2007109850A - Manufacturing method of electric double layer capacitor, and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a good heat sealer in which the welding side where welding strength is uniform for sealing a container cannot exfoliate easily, so as to improve the durability and reliability of an electric double layer capacitor provided with: a capacitor body consisting of a polarizable electrode, a separator, and a collector electrode; and a heat sealer for sealing the capacitor body with electrolytic solution in the container formed from laminated film of resin with a metal interlayer. <P>SOLUTION: A process for forming a heat sealer sets up: a primary processing for heating it only in a predetermined period at a predetermined surface pressure by using a sealer, while sandwiching junction overlap width in which lamination films overlap; and a secondary processing for cooling it only in a predetermined period at a predetermined surface pressure by using a sealer, while sandwiching junction overlap width in which lamination films overlap. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for manufacturing an electric double layer capacitor.

  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.

  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 (Patent Document 1).

The container is made from a resin laminated film having a metal intermediate layer, and heat-sealing (heat-sealing) the joining allowance of the overlapping laminated films, thereby sealing the inside that houses the capacitor body together with the electrolytic solution ( A heat welding part) is provided.
JP2003-124078

  An object of the present invention is to provide a method and an apparatus for realizing the production of an electric double layer capacitor having a good heat seal portion of a container and having high durability and reliability in consideration of such a conventional technique. To do.

  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 method of manufacturing the electric double layer capacitor, the step of forming the heat seal portion of the container includes a primary treatment in which a laminated film is sandwiched by a sealer and heated to a predetermined surface pressure for a predetermined time by a sealer. And a secondary treatment in which the joining margin of the laminated films is sandwiched by the sealer and cooled to a predetermined surface pressure for a predetermined time.

  The second invention is characterized in that, in the method for manufacturing an electric double layer capacitor according to the first invention, the surface pressure applied to the secondary treatment is set higher than the surface pressure applied to the primary treatment.

  According to a third aspect of the present invention, in the method of manufacturing the electric double layer capacitor according to the first aspect, the sealer of the secondary treatment is maintained at a predetermined temperature below the melting point of the resin layer of the joining margin by the cooling gas. Features.

  A fourth invention is characterized in that, in the method for manufacturing an electric double layer capacitor according to the third invention, the cooling gas is a highly dry, inert gas at normal temperature.

  5th 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 collector electrode, and a laminated film of a resin having a metal intermediate layer In a manufacturing apparatus for an electric double layer capacitor comprising: a means for forming a heat seal portion of a container, a means for performing a primary treatment of heating a predetermined surface pressure for a predetermined time with a joining margin of laminated films sandwiched therebetween And a means for performing a secondary treatment that cools to a predetermined surface pressure for a predetermined time with a bonding margin of overlapping laminated films interposed therebetween.

  In the first invention, the resin layer between the joining margins is melted and welded (fused) while receiving a predetermined surface pressure by the primary treatment. This resin is cooled by the secondary treatment and solidifies while receiving a predetermined surface pressure. In the secondary treatment, the resin between the bonding margins is cooled to a predetermined surface pressure for a predetermined time and the cooling rate is uniformized, so that generation of minute distortion is suppressed and the resin is solidified to a uniform thickness. . As a result, it is possible to obtain a good heat seal portion in which the weld surface having a uniform weld strength is difficult to peel off for sealing the container, and the durability and reliability of the electric double layer capacitor can be improved.

  In the second invention, by increasing the surface pressure of the secondary treatment to be higher than the surface pressure of the primary treatment, it is possible to effectively suppress the occurrence of minute distortion accompanying the solidification of the resin.

  In the third invention, the sealer of the secondary treatment is maintained at a predetermined temperature by the cooling gas, and the molten resin between the joining margins can be efficiently and uniformly cooled.

  In the fourth invention, the composition of the capacitor body and the heat sealing of the container are also processed in a highly dry inert atmosphere (inside the glove box), but the secondary processing cooling gas is highly dried at room temperature. Therefore, even if the cooling gas is released from the sealer of the secondary treatment, the environment (highly dry inert atmosphere) suitable for manufacturing the electric double layer capacitor is not impaired.

  In the fifth invention, since a means for performing the primary treatment and a means for performing the secondary treatment are provided, a good heat seal portion that is difficult to peel off the weld surface having a uniform weld strength for sealing the container is obtained, and the durability is improved. In addition, a highly reliable electric double layer capacitor can be reasonably manufactured.

  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.

  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.

  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, a housing portion for the stacked body 20 is formed 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.

  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 heat-sealed (heat-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 side 12a that can be opened is heat sealed (thermal welding).

  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. For the laminated film as these materials, an aluminum foil intermediate layer and a resin sandwiching the intermediate layer are used. The surface layer is formed into a three-layer structure. The surface layer constituting the outer surface of the container 10 is formed of a resin having high heat resistance, and the surface layer constituting the inner surface of the container 10 is formed of a resin having high heat welding (melting) property.

  In the manufacturing process of the electric double layer capacitor, each constituent material of the electric double layer capacitor (a component of the laminated body, a component of the container, and a terminal member) is dried. Thereafter, inside the glove box (set to an inert atmosphere with a dew point temperature of −60 ° C.), the composition of the predetermined laminate 20, the bundling portion of the same polarity of the lead portion, and the terminal 21 corresponding to the polarity In addition to the heat sealing of the three sides 12b to 12d excluding the one side 12a from which the pair of terminals 21 (part thereof) is drawn, the injection of the electrolytic solution into the container 10, and the impregnation and electrolytic purification of the electrolytic solution, The steps up to the heat sealing of the remaining side of the container 10 are sequentially performed.

  FIG. 2 illustrates a process of forming a heat seal portion on three sides 12b to 12d excluding one side from which a pair of terminals 21 (a part thereof) of the container 10 is pulled out. A sealer 30 including an upper mold 32 that can contact and separate from the mold 31 and a sealer 40 including an upper mold 42 that can contact and separate from the lower mold 31 are disposed adjacent to each other. A recess 33 is formed on the upper surface of the lower die 31 to receive the recess 11a (outer surface protrusion) of the bottom member 10a. The bottom member 10a is positioned in the concave portion 33 of the lower mold 31, and the laminated body 20 is housed inside thereof, and the lid member 10b is placed thereon (see FIG. 3).

  A heating surface 34 (convex surface) that sandwiches the three sides 12b to 12d (joining allowance) of the container 10 between the lower surface of the upper mold 31 that can be brought into and out of contact with the lower mold 31 of the sealer 30 and the flat surface surrounding the concave portion 33 of the lower mold 31. And the entire region is maintained at a predetermined temperature exceeding the melting point of the resin layer between the joining margins. A cooling surface 43 that sandwiches the three sides 12b to 12d of the container 10 between the lower surface of the upper die 42 that can contact and separate from the lower die 31 of the sealer 40 and the flat surface surrounding the recess 33 of the lower die 31 is provided. Is maintained at a predetermined temperature above the melting point of the resin layer between the joining margins.

  In the step of forming the heat seal portion, the joining margins 12b to 12d of the container 10 are sandwiched between the flat surface surrounding the recess 33 of the lower mold 31 of the sealer 30 and the heating surface 34 of the upper mold 32, A primary process is performed in which the heating surface 34 is pressed against a predetermined surface pressure for a predetermined time. When the primary processing is completed, the lower mold 31 is quickly moved to the sealer 40, and the joining margins 12b to 12d of the container 10 are sandwiched between the flat surface surrounding the recess 33 of the lower mold 31 and the cooling surface 43 of the upper mold 42. Then, a secondary process is performed in which the cooling surface 43 of the upper mold 42 is pressed against a predetermined surface pressure for a predetermined time. The surface pressure of the secondary treatment is set higher than the surface pressure of the primary treatment.

For example, when the surface layer constituting the inner surface of the container 10 is PP (polypropylene), the primary treatment is performed for a time (15 sec) at a surface pressure (4.0 kgf / cm ² ) due to the heating surface 34 at a temperature (200 ° C.). Just press. In the secondary treatment, the cooling surface 43 at a temperature (50 ° C.) is pressed against the surface pressure (5.0 kgf / cm ² ) for a time (5 sec).

  The resin layer between the joining margins is fused (fused) by the primary treatment while being melted and receiving a predetermined surface pressure. In the molten state, this resin is cooled by secondary treatment and solidifies while receiving a predetermined surface pressure. In the secondary treatment, the cooling rate of the resin during the bonding allowance is made uniform by the cooling surface 43 of the upper mold 42 (the entire region is maintained at a predetermined temperature exceeding the melting point of the resin layer during the bonding allowance). Generation of distortion is suppressed, and it becomes solidified to a uniform thickness. As a result, it is possible to obtain a good heat seal portion in which the weld surface having a uniform weld strength is difficult to peel off in sealing the container 10, and the durability and reliability of the electric double layer capacitor can be greatly enhanced.

  The sealer 30 including the upper mold 32 that can contact and separate from the lower mold 31 and the sealer 40 including the upper mold 42 that can contact and separate from the lower mold 31 are arranged adjacent to each other, and the lower mold 31 is configured to be movable. Therefore, when the interval between the primary process and the secondary process is minimized and the primary process is completed, the process can be quickly shifted to the secondary process in the molten state of the resin. The surface pressure of the secondary treatment is set higher than the surface pressure of the primary treatment, and the occurrence of resin distortion is effectively suppressed.

  FIG. 4 is for explaining another embodiment, and in the secondary treatment sealer 40, the entire cooling surface 43 of the upper mold 42 is maintained at a predetermined temperature below the melting point of the resin layer between the joining margins. A passage 45 (space) along the cooling surface 43 is provided inside the upper mold 42, and the cooling surface 43 is opened through a large number of small holes 45a. A facility (not shown) for supplying a cooling gas to the passage 45 is provided. When the cooling gas is introduced into the passage 45, the passage 45 flows through the passage 45 and blows out from a large number of small holes 45a. In the cooling gas supply facility, the cooling gas is managed at a predetermined temperature (50 ° C. when the surface layer constituting the inner surface of the container 10 is PP). Reference numeral 31 denotes a lower mold, which is held at a position corresponding to the upper mold 42 after the completion of the primary processing.

  The entire area of the cooling surface 43 is maintained at a predetermined temperature by the cooling gas, and the molten resin during the bonding allowance can be efficiently and uniformly cooled. Although the temperature of the cooling surface 43 is increased by the amount of heat received from the three sides 12b to 12d of the container 10 during the secondary processing, the cooling surface 43 is lowered to a predetermined temperature by the cooling gas until the start of the next secondary processing. Therefore, in this embodiment, it is possible to efficiently obtain a good heat seal portion in which the welded surface having a uniform welding strength for sealing the container 10 is difficult to peel off in a short time. Since the cooling gas blows out from the cooling surface 43 of the upper mold 42, an inert gas having a dew point temperature of −60 ° C. is used to protect the environment of the glove box.

  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 the primary processing and the secondary processing can be performed by the same sealer as the three sides 12b to 12d.

It is composition explanatory drawing of the electrical double layer capacitor which concerns on embodiment of this invention. It is explanatory drawing of the process which similarly forms a heat seal part. It is explanatory drawing of the process which similarly forms a heat seal part. It is explanatory drawing of the sealer which concerns on another embodiment.

Explanation of symbols

10 Container 10a Bottom side part 10b Cover side part 12a-12d Flange (connection allowance)
20 Capacitor body (laminated body)
21, 21a, 21b Terminal 30, 40 Sealer 31 Lower mold 32, 42 Upper mold 33 Heating surface 43 Cooling surface 45 Cooling gas passage 45a Small hole

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. In the method for manufacturing a multilayer capacitor, the step of forming the heat seal portion of the container includes a primary treatment in which a laminated film is sandwiched by a sealer and a laminated surface is heated to a predetermined surface pressure for a predetermined time, and is laminated by a sealer. And a secondary process of cooling to a predetermined surface pressure for a predetermined time with a bonding margin of overlapping films interposed therebetween.   2. The method of manufacturing an electric double layer capacitor according to claim 1, wherein the surface pressure applied to the secondary treatment is set higher than the surface pressure applied to the primary treatment.   2. The method for manufacturing an electric double layer capacitor according to claim 1, wherein the sealer of the secondary treatment is maintained at a predetermined temperature lower than the melting point of the resin layer of the joining margin by the cooling gas.   4. The method of manufacturing an electric double layer capacitor according to claim 3, wherein the cooling gas is a highly dry and normal temperature inert gas.   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. In a multilayer capacitor manufacturing apparatus, as a means for forming a heat seal portion of a container, a means for performing a primary treatment of heating a predetermined surface pressure for a predetermined time with a laminated film overlapping joining margin, and a laminated film overlapping. An apparatus for producing an electric double layer capacitor, comprising: a secondary process of sandwiching a bonding margin and cooling to a predetermined surface pressure for a predetermined time.

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