JP2007019082A - Electric double layer capacitor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric double layer capacitor capable of efficiently manufacturing a coil former type electric double layer capacitor at a low cost, that is, an electrode structure containing an external terminal for a vessel can be formed simply and a wound body can also be formed efficiently, regarding the coil former type electric double layer capacitor and a manufacturing method for the electric double layer capacitor. <P>SOLUTION: A mandrel 25 for a winding is fitted in the wound body 10. The mandrel 25 is composed of a pair of electrodes 26a and 26b and an intermediate section 27 insulating these electrodes. The winding-start ends of electrode sheets 13 and 14 having corresponding polarities are joined to each of the electrodes 26a and 26b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  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.

For such an electric double layer capacitor, a wound body formed of a strip-shaped positive electrode sheet, a strip-shaped negative electrode sheet, and a strip-shaped separator sandwiched therebetween, and the wound body together with an electrolytic solution And a container for sealing (Patent Document 1, Patent Document 2). The electrode sheet is composed of a polarizable electrode (formed from a carbonaceous material) and a collecting electrode (formed from an aluminum foil). A pair of terminals are arranged outside the container, and an electrode sheet corresponding to the polarity of the wound body is connected to these external terminals.
JP 2001-052969 A JP 2003-086472 A

  In the case of Patent Document 1, in order to connect between the external terminal of the container and the electrode sheet corresponding to the polarity of the wound body, the side edge of each electrode sheet (for example, the upper edge of the positive electrode sheet, negative A margin (a part of the aluminum foil) where the collecting electrode is exposed is set on the lower edge of the electrode sheet), and in the process of forming the wound body, the electrode tab is welded to the margin of each electrode sheet. In the case of Patent Document 2, the margin of each electrode sheet (a part of the aluminum foil) is crushed by using a special welding jig after the wound body is formed, and the disk part constituting a part of the external terminal of the container is formed. Welded. In any case, the connection between the external terminal of the container (electrical outlet / outlet part) and the electrode sheet corresponding to the polarity of the wound body is easy because the displacement of the electrode tab and the margin may be crushed unevenly. Don't go to In Patent Document 2, a complicated welding jig is also required.

  An object of the present invention is to provide an electric double layer capacitor and a method for manufacturing the same, in which an electrode structure including an external terminal of a container is simple and a wound body can be efficiently formed in consideration of such conventional techniques.

  A first invention includes a wound body formed of a strip-shaped positive electrode sheet, a strip-shaped negative electrode sheet, and a strip-shaped separator sandwiched therebetween, and a container that seals the wound body together with an electrolyte. The winding body is provided with a core rod for winding, and the core rod is composed of a pair of electrode portions and an intermediate portion that insulates between them, An electric double layer capacitor, wherein winding start ends of electrode sheets each having a corresponding polarity are joined.

  According to a second aspect of the present invention, in the electric double layer capacitor according to the first aspect of the present invention, the container includes a cylindrical body and a lid that closes each open end thereof, and a hole is formed in the center of the lid, while the wound body Each electrode portion of the core rod is characterized by forming a pair of external terminals protruding from the container through a hole in the lid.

  According to a third aspect of the invention, in the electric double layer capacitor according to the second aspect of the invention, the hole of the lid is a screw hole, and each electrode portion of the core rod includes a screw portion that is screwed into the screw hole of the lid. And

  According to a fourth aspect of the present invention, in the electric double layer capacitor according to the second aspect of the present invention, the peripheral edge of the lid is provided with a fitting groove with the opening end of the cylindrical body.

  According to a fifth aspect of the present invention, there is provided a wound body formed of a strip-shaped positive electrode sheet, a strip-shaped negative electrode sheet, and a strip-shaped separator sandwiched therebetween, and a container that seals the wound body together with an electrolyte. In the method of manufacturing an electric double layer capacitor comprising: a winding core rod formed of a pair of electrode portions and an intermediate portion that insulates between them, one positive electrode portion of the core rod is The winding start end of the electrode sheet is joined to the other electrode portion, and the winding start end of the negative electrode sheet is joined, and the separator is sandwiched between the positive electrode sheet and the negative electrode sheet. A step of forming a wound body by rotating the core rod.

  In the first invention, since the core rod for winding is provided, the wound body can be formed easily and accurately. When the core rod is set so that the winding start end of the electrode sheet corresponding to the polarity is joined to each of the electrode parts, and a part of each electrode part protrudes from the container, the external terminal (electrical outlet / outlet part) of the container also becomes It can be formed easily and easily. As a result, it is possible to obtain an effect that the wound type electric double layer capacitor can be manufactured efficiently and inexpensively.

  In the second invention, the wound body is housed in a cylindrical body of the container, and each electrode portion of the core rod is passed through the hole of the lid, and these lids are assembled to both ends (openings) of the cylindrical body, The part protruding from the lid of the electrode part becomes the external terminal of the container. That is, the external terminal of the container can be easily and easily formed by the core rod of the wound body.

  In the third invention, the wound body is accommodated in the cylindrical body of the container, and the lid is assembled to both ends (openings) of the cylindrical body while screwing the threaded portion of the core rod into the screw hole of the lid. A portion protruding from the lid of each electrode portion becomes an external terminal of the container. The external terminal of the container can also be easily and easily formed by the core rod of the wound body, and the lid can be easily and accurately assembled to the cylinder body via the core rod of the wound body by screws.

  In the fourth invention, good sealing performance can be easily and easily secured by the fitting groove of the lid.

  In the fifth invention, the winding body can be formed easily and accurately by rotating the winding core rod. In addition, when the core rod is set so that the winding start end of the electrode sheet corresponding to the polarity is joined to each of the electrode parts and a part of each electrode part protrudes from the container, the external terminal of the container can be easily and easily Can form. Joining (welding) the electrode part to the winding start end of the electrode sheet is simple and easy because it is not after the winding process or after winding, and is a pre-treatment process before starting winding. Yes. Further, unlike the prior art (Patent Document 1 and Patent Document 2), it is not necessary to weld the external terminal and the collector electrode. As a result, it is possible to obtain an effect that the wound type electric double layer capacitor can be manufactured efficiently and inexpensively.

  An electric double layer capacitor according to an embodiment of the present invention will be described based on the drawings. 1 to 5, 10 is a wound body (capacitor main body), 11 is a container for sealing the wound body 10 together with the electrolyte, and 12 is a pair of external terminals (capacitor electrode: electricity outlet / outlet portion). ).

  The wound body 10 is formed by winding a belt-like positive electrode sheet 13, a belt-like negative electrode sheet 14, and a belt-like separator 15 sandwiched therebetween (see FIG. 6). The positive electrode sheet 13 and the negative electrode sheet 14 include a collecting electrode 16 and a polarizable electrode 17. The collector electrode 16 is made of a strip-shaped metal foil (for example, an aluminum foil), and an electrode tab 16a is formed integrally with the winding start end toward one side (see FIGS. 4 and 5). The polarizable electrode 17 is mainly made of a carbonaceous material, and is formed on both surfaces of the collector electrode 16 (excluding the electrode tab 16a).

  The strip-shaped separator 15 is formed of a porous film made of paper or resin. Fold the band width (dimension in the short direction) in half, sandwich the positive electrode sheet 13 or negative electrode sheet 14 inside it, and put the negative electrode sheet 14 or positive electrode outside the double fold By rolling the sheets 13 while overlapping them, the sheet 13 is sandwiched between the positive electrode sheet 13 and the negative electrode sheet 14. The two-fold separator 15 is set longer than the length of the electrode sheets 13 and 14 (dimension in the longitudinal direction) by one turn of the wound body. In addition, by using two separate members instead of the two-folded separator 15, these may be wound while being stacked on the electrode sheets 13 and 14 and the four layers.

  The container 11 is composed of a cylindrical body 18 and lids 19a and 19b (upper and lower lids) that close both ends (open ends), and these are provided with necessary materials such as insulation and corrosion resistance against an electrolytic solution. In this case, the cylindrical body 18 is formed in a cylindrical shape, and the lids 19a and 19b are formed in a disk shape. A boss portion 20 and a screw hole 21 passing through the center of the lid 19a, 19b in the axial direction are provided in the center of the lid 19a, 19b, and an annular groove 22 is formed in the peripheral edge of the lid 19a, 19b. (See FIGS. 2 and 3). Reference numeral 23 denotes an attachment portion of a gas vent valve (not shown), which is set to one lid 19b (upper lid). The degassing valve is for removing generated gas accompanying charging / discharging outside the container.

  The wound body 10 is provided with a core rod 25 for winding. The core rod 25 is formed of a pair of electrode portions 26a and 26b and an intermediate portion 27 that insulates between them, and electrode tabs 15a having polarities corresponding to the electrode portions 26a and 26b are joined (for example, welded). The The electrode portions 26a and 26b are formed of an aluminum rod, and are provided with screw portions 28 that are screwed into the screw holes 21 of the lids 19a and 19b. In the illustrated case, the screw portion 28 is processed on the tip side of the electrode portions 26a and 26b, and the external terminal 12 of the container 11 is formed by a portion protruding from the boss portion 20 of the lids 19a and 19b.

  With such a configuration, the winding core 10 is provided, so that the wound body 10 can be formed easily and accurately. The core rod 25 is joined to the electrode portions 26a and 26b at the winding start end portions of the electrode sheets 13 and 14 corresponding to the polarities, and the external terminals 12 of the container 11 are also simple and easy due to both end portions protruding from the lids 19a and 19b. Can be formed. That is, the wound body 10 is housed in the cylindrical body 18 of the container 11, and the screw portions 28 of the core rod 25 are screwed into the screw holes 21 of the lids 19 a and 19 b, and the lids 19 a and 19 b are connected to both ends ( By assembling in the opening), the portions protruding from the lids 19a, 19b of the electrode portions 26a, 26b become the external terminals 12 of the container 11. The lids 19a and 19b are easily and accurately assembled to the cylindrical body 18 via the core rod 25 of the wound body 10 with screws.

  The lids 19a and 19b may be provided with simple holes (through holes through which the electrode portions 26a and 26b of the core rod 25 can be inserted) instead of the screw holes 25, and screwed into the screw portions of the electrode portions 26a and 26b. It is also conceivable to fasten to the open end of the cylindrical body 18 with a mating nut.

  The manufacturing process of the electric double layer capacitor will be described with reference to FIG. Steps (a) to (d) are performed in a highly dry inert atmosphere.

  In the step (a), the electrode tabs 16a of the electrode sheets 13 and 14 are joined (for example, welded) to the electrode portions 26a and 26b of the core rod 25. The electrode sheet 14 (or 13) on the outer side of the winding is sandwiched inside the two-folded separator 15, and the core rod 25 is rotated. As a result, the outer electrode sheet 14 (or 13) wound between the two folded separators 15 and the electrode sheet 13 (or 14) overlapping the inner winding are wound around the core rod 25, and the electrode sheet 13 and 14 are formed in a wound body 10 in which a separator 15 is interposed. The two-fold separator 15 is set longer than the length (longitudinal dimension) of the electrode sheets 13 and 14 by one turn of the wound body 10, and forms the outermost winding layer of the wound body 10. .

  In the step (b), the wound body 10 is housed in the cylindrical body 18 of the container 11, and the screw hole 21 of the lid 19 a (lower lid) is screwed to one end (screw portion 28) of the core rod 25. When the lid 19a is rotated in the direction of the arrow, the screwing with the core rod 25 proceeds, and the tip of the core rod 25 is moved from the screw hole 21 as it approaches the winding body 10 positioned (fixed) inside the cylindrical body 18. The annular groove 22 is fitted into the open end of the cylindrical body 18 while protruding.

  It is also conceivable to rotate the core rod 25 of the wound body 10 instead of rotating the lid 19a. In other words, the lid 19a is assembled by fitting the annular groove 22 to the opening end of the cylinder 18, and the core rod 25 is rotated while the winding body 10 is housed in the cylinder 18, thereby screwing the lid 19a. One end (screw part 28) of the core rod 25 is screwed into the state protruding from the hole 21.

  In the step (c), the electrolytic solution is injected into the cylindrical body 18 with the lid 19a (bottom), and the wound body 10 (the polarizable electrode 17 and the separator 15) is sufficiently impregnated.

  In step (d), the other end (screw portion 28) of the core rod 25 is screwed into the screw hole 21 of the lid 19b (upper lid). When the lid 19b is rotated in the direction of the arrow, the screwing with the core rod 25 proceeds, and the tip of the core rod 25 is screwed into the screw hole as it approaches the fixed wound body 10 through the lid 19b inside the cylindrical body 18. The annular groove 22 is fitted into the open end of the cylindrical body 18 while protruding from 21. Thereafter, the degassing valve is assembled to the mounting portion 23 of the lid 19b.

  By such steps (a) to (d), it is possible to obtain an effect that a wound type electric double layer capacitor can be manufactured efficiently and inexpensively.

  Specifically, the winding body 10 can be formed easily and accurately by rotating the winding core rod 25. The core rod 25 is joined to the electrode portions 26a and 26b at the winding start end portions of the electrode sheets 13 and 14 corresponding to the polarities, and the external terminals 12 of the container 11 are also simple and easy due to both end portions protruding from the lids 19a and 19b. Can be formed. Joining (for example, welding) between the electrode portions 26a and 26b and the winding start end portions of the electrode sheets 13 and 14 is not performed during the winding process or after winding, but is performed before the winding starts, so that the winding portion is suppressed. Can be done easily and easily. Further, unlike the prior art (Patent Document 1 and Patent Document 2), welding between the external terminal 12 and the collector electrode 16 is not necessary.

It is sectional drawing explaining the structure of an electrical double layer capacitor. It is sectional drawing of a lid | cover. It is a disassembled perspective view explaining the structure of an electric double layer capacitor. It is explanatory drawing which concerns on the core rod for winding. It is local sectional drawing of an electrode sheet. It is process explanatory drawing which concerns on the manufacturing method of an electrical double layer capacitor.

Explanation of symbols

10 Winding body (capacitor body)
DESCRIPTION OF SYMBOLS 11 Container 12 External terminal 13, 14 Electrode sheet 15 Separator 18 Cylindrical body 19a, 19b Lid 21 Screw hole 22 Annular groove (fitting groove)
25 Core rod for winding 26a, 26b Electrode portion 27 Intermediate portion 28 Screw portion

Claims (5)

  An electric double layer comprising: a wound body formed of a strip-shaped positive electrode sheet, a strip-shaped negative electrode sheet, and a strip-shaped separator sandwiched therebetween; and a container for sealing the wound body together with an electrolyte solution In the capacitor, the wound body is provided with a winding core rod, and the core rod includes a pair of electrode portions and an intermediate portion that insulates between them, and the polarity corresponds to each of the electrode portions. An electric double layer capacitor, wherein a winding start end portion of an electrode sheet is joined.   The container is composed of a cylinder and a lid that closes each open end thereof, and a hole is formed in the center of the lid, while each electrode portion of the core rod of the wound body protrudes from the container through the hole of the lid. 2. The electric double layer capacitor according to claim 1, wherein an external terminal is formed.   3. The electric double layer capacitor according to claim 2, wherein the hole of the lid is a screw hole, and each electrode portion of the core rod includes a screw portion that is screwed into the screw hole of the lid.   The electric double layer capacitor according to claim 2, further comprising a fitting groove on the peripheral edge of the lid with the opening end of the cylindrical body.   An electric double layer comprising: a wound body formed of a strip-shaped positive electrode sheet, a strip-shaped negative electrode sheet, and a strip-shaped separator sandwiched therebetween; and a container for sealing the wound body together with an electrolyte solution In a method for manufacturing a capacitor, a winding core rod formed of a pair of electrode portions and an intermediate portion that insulates between them is used, and a positive electrode sheet is wound on one electrode portion of the core rod. Join the starting end of the negative electrode sheet to the other electrode, and rotate the winding core while sandwiching the separator between the positive electrode sheet and the negative electrode sheet. The process of forming a wound body by this, The manufacturing method of the electrical double layer capacitor characterized by the above-mentioned.

Images