JP2012175084A - Power storage device, manufacturing method of power storage cell and manufacturing method of power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric double-layer capacitor module with improved heat dissipation efficiency and is less adversely affected by that.SOLUTION: An electric double-layer capacitor module 1 includes: an electric double-layer capacitor cell 10 having a power storage body 11 and a bag body 15 enclosing the power storage body 11 therein; and a housing 20 for housing the cell 10 therein. Also, the bag body 15 includes: a front surface part 15a; a back surface part 15b facing the surface part 15a at a prescribed interval; and side parts (an upper part 15c, a lower part 15d and both side parts 15e, 15f) provided between the front surface part 15a and the back surface part 15b. Both the side parts 15e and 15f form a plurality of fins 16 which are aligned in a direction from the front surface part 15a to the back surface part 15b and have a surface parallel to the front surface part 15a and the back surface part 15b.

Description

  The present invention relates to a power storage device such as an electric double layer capacitor module, a method for manufacturing a power storage cell constituting the power storage device, and a method for manufacturing a power storage device.

  A cell of an electric double layer capacitor module, which is a kind of power storage device, has a power storage unit formed by laminating polarizable electrodes (positive electrode sheet and negative electrode sheet) together with a separator, and a tab terminal electrically connected to the polarizable electrode. A bag body is provided that encloses the electric storage body in a state in which the (positive electrode side current collecting terminal and negative electrode side current collecting terminal) are pulled out. When an electric double layer capacitor module is manufactured using such a cell, a plurality of cells are stacked and accommodated in the casing, and the positive and negative current collecting terminals of adjacent cells are connected between the cells. Connect in series with connecting parts. Then, the positive electrode current collector terminal drawn from the cell at one end of the laminate is connected to the positive electrode terminal provided on the lid of the casing, and the negative electrode current collector drawn from the cell at the other end is connected. The electrical terminal is connected to the negative terminal provided on the lid of the housing. By connecting an electric load between the positive terminal and the negative terminal, a current flows through the electric load.

  Since the internal resistance of the electric double layer capacitor module is small, a problem associated with heat generation is unlikely to occur when a small current flows. However, when a large current flows, for example, when used as a drive battery for an electric vehicle, a problem associated with heat generation occurs. Generally, in the electric double layer capacitor cell, when the temperature inside the bag (particularly the temperature of the electrolyte solution filled in the bag) is 70 ° C. or more, the charge / discharge efficiency is remarkably lowered. Therefore, an electric double layer capacitor module with improved heat dissipation efficiency is desired.

  Patent Document 1 discloses an electric double layer capacitor module with improved heat dissipation efficiency. The electric double layer capacitor module described in Patent Document 1 includes a first case and a second case in which a laminated body formed by laminating a plurality of electric double layer capacitor cells together with a heat sink in which ventilation holes are formed, and the first case and the second case. A first housing and a third housing for housing the second housing; Further, the first casing and the second casing are accommodated in the third casing so that a predetermined gap is provided therebetween. An exhaust fan is attached to the third casing facing the predetermined gap. By driving the exhaust fan, a flow of air flowing out from the ventilation hole of the heat radiating plate through the predetermined gap is formed. According to this air flow, the heat generated in the electric double layer capacitor cell is discharged.

  Similarly, Patent Document 2 discloses an electric double layer capacitor module with improved heat dissipation efficiency. According to Patent Document 2, the electric double layer capacitor module is fixed so as to be suspended from the control box in the capacitor unit. When this capacitor unit is mounted on a vehicle, for example, the capacitor unit is installed on the vehicle so that the electric double layer capacity module suspended from the control box is exposed to the outside air. When the traveling wind is applied to the electric double layer capacitor module exposed to the outside air, the electric double layer capacitor module is dissipated.

  Patent Document 3 discloses a lithium battery with improved heat dissipation efficiency. The lithium battery described in Patent Document 3 includes a laminate of a positive electrode, a separator layer, and a negative electrode. A plurality of the laminated bodies are diffracted and stacked. A heat radiating plate is disposed in the valley fold portion of the stacked laminate. And a laminated body is accommodated in a housing so that the front-end | tip part of a heat sink may contact the inner wall of the housing which accommodates a laminated body. The heat dissipation of the laminate is promoted by the contact between the heat sink and the housing.

JP 2010-171214 A JP 2003-272972 A Japanese Patent No. 3972411

(Problems to be solved by the invention)
According to Patent Document 1, since the ventilation holes are formed in the heat sink arranged between the electric double layer capacitor cells, the thickness of the heat sink is large. Therefore, the size (particularly the length in the stacking direction) of the electric double layer capacitor cell is larger than the normal size accordingly. Further, since the predetermined gap is provided in the third casing, the size of the third casing is also large. Furthermore, since the exhaust fan is attached to the third housing, the overall size is also large. That is, the electric double layer capacitor module described in Patent Document 1 causes an increase in size by improving the heat dissipation efficiency.

  According to Patent Document 2, the capacitor unit must be installed so that the electric double layer capacitor module suspended from the control plate is exposed to the outside air. Therefore, this electric double layer capacitor module cannot be used when it cannot be exposed to the outside air. That is, the installation location of the electric double layer capacitor module described in Patent Document 2 is limited in order to improve the heat dissipation efficiency, and as a result, the usage of the electric double layer capacitor module is limited.

  According to Patent Document 3, in order to bring the heat sink disposed in the valley fold portion of the folded laminate into contact with the housing wall, the dimensional accuracy of the heat sink and the width dimension of the folded laminate. (Length of the part into which the heat sink is inserted) The accuracy is required. Since such dimensional accuracy must be ensured, productivity deteriorates. That is, the lithium battery described in Patent Document 3 causes a deterioration in productivity in order to improve the heat dissipation efficiency.

  As described above, conventionally, various adverse effects have been caused by improving the heat dissipation efficiency. Further, improvement in heat dissipation efficiency is not a problem required only for the electric double layer capacitor module. As seen in Patent Document 3, the heat dissipation efficiency should be good even with other power storage devices (for example, lithium batteries).

  An object of the present invention is to provide an electricity storage device with improved heat dissipation efficiency and less harmful effects, a method for producing an electricity storage cell constituting such an electricity storage device, and a method for producing such an electricity storage device. To do.

(Means for solving the problem)
The present invention is an electrical storage device comprising an electrical storage body and an electrical storage cell comprising a bag body enclosing the electrical storage body, and a housing for accommodating the electrical storage cell therein, the bag body comprising a surface portion, A back surface portion facing the front surface portion; and a side portion formed between the front surface portion and the back surface portion, wherein at least a part of the side portion is aligned in a direction from the front surface portion toward the back surface portion. In addition, an electricity storage device is provided that forms a plurality of fins having surfaces parallel to the front surface portion and the back surface portion.

  According to the electricity storage device of the present invention, the side portion of the bag of the electricity storage cell forms a fin. Therefore, the heat generated in the electricity storage body in the bag body is dissipated to the outside through the fins formed in the bag body itself. For this reason, the heat dissipation efficiency is improved.

  Moreover, according to the electricity storage device of the present invention, heat is efficiently radiated through the fins formed on the bag body of the electricity storage cell without attaching an exhaust fan to the housing. Therefore, the power storage device can be configured in a compact manner. In addition, since it is not a structure that requires the electricity storage device to be exposed to the outside, the usage application is not particularly limited by the limitation of the installation location. Furthermore, since special dimensional accuracy is not required, productivity does not deteriorate. Thus, the present invention can provide a power storage device with improved heat dissipation efficiency and less adverse effects.

  The power storage device to which the present invention is applied is any power storage device as long as it includes a power storage cell having a power storage body and a bag body that encloses the power storage body, and a housing that houses the power storage cell inside. But you can. For example, the present invention can be applied to an electric double layer capacitor module including an electric double layer capacitor cell and a housing that accommodates the electric double layer capacitor cell therein. Moreover, even if it is a lithium battery, if it is packaged by the bag body, this invention is applicable. In addition, the electrical storage cell accommodated in a housing may be single, and plural may be sufficient as it.

  The bag is preferably made of a flexible film, and the fin is in contact with the inner wall of the housing. According to this, when the fin comes into contact with the housing wall, the heat of the fin is quickly transmitted to the housing side, and further, the heat is quickly radiated from the housing to the outside. Therefore, the heat dissipation efficiency is further improved. Moreover, since the bag is made of a flexible film, the fins are also formed of the flexible film. Therefore, even if the dimensions of the fins vary, the variation in dimensions is absorbed by bending when the tips of the fins contact the body wall. Therefore, it is not necessary to strictly manage the dimensions of the fins and the dimensions of the housing, and as a result, productivity is improved.

  Moreover, the said bag body is good to be formed by welding four sides which comprise each circumference part of the flexible 1st film and 2nd film which are rectangular shapes. In this case, a folding portion formed by folding one or more times along the side is provided on two opposing sides of the four sides constituting the peripheral portion of the first film, and the fin is The first film may be formed by welding the folded portion of the first film to the peripheral portion of the second film.

  According to this, a bag body is formed by welding the periphery of two flexible films and bonding these flexible films together. Further, the folded portions formed on the two opposite sides of the four sides constituting the peripheral portion of the first film are welded to the peripheral portion of the second film, so that fins can be easily attached to the side portions of the bag body. Can be formed.

  In the said invention, a "folding part" represents the part folded along the edge | side of a rectangular film. Further, the folded portion is folded at least once. Specifically, when forming the folded portion on one side of the rectangular film, first, the film is folded (folded) toward the inside of the film in parallel with the side. Next, the folded portion is further folded back toward the outside of the film (folded). In this way, the folded portion is formed. In addition, the fold line formed when the film is folded (when the mountain is folded) and the fold line formed when the folded portion is folded (when the valley is folded) are almost the same as the side where the folded portion is formed. It should be parallel.

  The power storage device of the present invention may include a plurality of the power storage cells, and the plurality of power storage cells may be stacked in the casing. According to this, the electrical storage device which can endure long-time use can be provided by connecting the several electrical storage cell laminated | stacked and arrange | positioned in the housing | casing in series.

  In addition, the present invention is a method for manufacturing a power storage cell including a power storage unit and a bag body in which the power storage unit is enclosed, and is rectangular and has two sides facing each other among the four sides constituting the periphery thereof. The power storage unit is provided between a flexible first film provided with a folded portion formed by being folded once or more along the side and a rectangular flexible second film. In a state where the peripheral portion of the first film including the folded portion is overlapped with the peripheral portion of the second film, the folded portion of the first film is overlapped with the second portion. And a fin forming step of forming a fin in a portion where the folded portion is provided by welding to a peripheral portion of the film.

  According to the method for manufacturing an electricity storage cell of the present invention, the peripheral portions of the flexible first film and the second film are overlapped by the overlapping step. A bag body can be formed by joining the peripheral portions of the two superimposed films by welding or the like. Moreover, the folding | returning part formed in 2 sides which oppose among the 4 sides which comprise the surrounding part of the 1st film formed in the rectangular shape is welded to the surrounding part of the 2nd film formed in the rectangular shape. Thereby, a fin is formed in the side part of the bag formed by the first film and the second film.

  In this case, a resin layer made of a resin that melts when the folded portion is welded to the peripheral portion of the second film may be formed on the inner surface side of the folded portion of the first film. . Here, the “inner surface side” is the same surface side as the surface constituting the interior of the bag formed by welding the first film and the second film. According to this, when the folded portion is welded to the peripheral portion of the second film, the resin constituting the resin layer formed on the inner surface side of the folded portion is melted so that the inner surface sides of the folded portions are In close contact. For this reason, the thin fin parallel to the front-surface part and back surface part of a bag body can be formed in the side part of the bag body formed with a 1st film and a 2nd film.

  The folded portion is formed with a mountain folded portion in which the first film is folded inward in parallel to a side on which the folded portion is formed, and from the mountain folded portion toward the outside of the first film. It is preferable that a valley fold portion that is folded back in parallel with the side is formed. Moreover, the manufacturing method of the electrical storage cell according to the present invention may further include a partition plate sandwiching step of sandwiching a flat partition plate between the mountain fold portion and the valley fold portion. And the said fin formation process is good to be implemented after the said superimposition process and the said partition plate clamping process. Moreover, the partition plate is good to be formed with the material (for example, aluminum) with favorable heat conductivity.

  The partition plate is sandwiched between the mountain fold portion and the valley fold portion of the folded portion, and the folded portion is welded to the peripheral portion of the second film in this state, so that the welding heat is evenly distributed to the folded portion via the partition plate. Go around. For this reason, a folding | returning part can be welded to the surrounding part of a 2nd film over the whole region. Moreover, when the resin layer comprised by the resin which melt | dissolves by welding is formed in the inner surface side of a folding | returning part, the inner surface side of a folding | returning part can be made to closely_contact | adhere at the time of welding by pinching | interposing a partition plate. it can.

  Further, the present invention is a method for manufacturing an electricity storage device including an electricity storage cell and an electricity storage cell including a bag body in which the electricity storage body is enclosed, and a housing that accommodates the electricity storage cell therein, and includes the steps described above. A stack forming step of forming a stacked body by stacking a plurality of the storage cells manufactured by the manufacturing method of the storage cell, and fins formed in the storage cells constituting the stacked body include: And a housing step of housing the laminated body in the housing so as to come into contact with an inner wall.

  According to the method for manufacturing an electricity storage device of the present invention, when the laminated body of electricity storage cells is accommodated in the housing, the laminate is formed such that the fins formed on the side portions of the bag body of each electricity storage cell are in contact with the walls of the housing. Is contained in the enclosure. When the fin comes into contact with the wall of the housing, the heat of the fin is quickly transmitted to the housing, and further, the heat is quickly radiated from the housing to the outside. Therefore, the heat dissipation efficiency is further improved. Moreover, since the bag is made of a flexible film, the fins are also formed of the flexible film. Therefore, even if the dimensions of the fins vary, the variation in dimensions is absorbed by bending when the tips of the fins contact the body wall. Therefore, it is not necessary to strictly manage the fin dimensions, and as a result, productivity is improved.

  The first film and the second film may be a laminate film having flexibility and insulation. For example, a 1st film and a 2nd film can be formed by forming an insulating resin layer on both surfaces of an aluminum thin film. Moreover, you may form the resin layer comprised by resin melted by welding on the said inner surface side of the 1st film and 2nd film which were formed in this way. Polypropylene resin is mentioned as resin melted by welding, but is not limited thereto.

  Further, similarly to the first film, the second film may be formed with folded portions on two opposite sides among the four sides constituting the peripheral portion. In this case, in a state where the folded portion of the first film and the folded portion of the second film are overlapped, they are preferably joined together by welding.

  Moreover, the manufacturing method of the electrical storage cell of this invention forms the said folding | returning part in 2 sides which oppose among the 4 sides which comprise the surrounding part of a rectangular-shaped 1st film (or 1st film and 2nd film). A folded portion forming step may be included.

It is a perspective view of the electric double layer capacitor module as an example of the electrical storage device concerning this embodiment. It is a perspective view of an electric double layer capacitor cell. It is a figure which shows the manufacturing process of a cell. It is a figure which shows the manufacturing process of a cell. It is a figure which shows the manufacturing process of an electrical double layer capacitor module. It is a figure which shows the manufacturing process of an electrical double layer capacitor module. It is a fragmentary sectional view of the 1st film and the 2nd film. It is the Z section enlarged view of Drawing 3 (D). It is a figure which shows the manufacturing process of the cell which concerns on a modification. It is a figure which shows the manufacturing process of the cell which concerns on a modification. It is a figure showing the cell which concerns on a modification.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a perspective view of an electric double layer capacitor module as an example of an electricity storage device according to the present embodiment. As shown in FIG. 1, the electric double layer capacitor module 1 includes a plurality of electric double layer capacitor cells 10 and a housing 20. The housing 20 has a container portion 21 and a lid portion 22. The container part 21 is open at the top in the figure. A lid 22 is attached to the opening. The plurality of electric double layer capacitor cells 10 are accommodated in the container portion 21 of the housing 20 in a state of being stacked via the heat dissipation plate 30. A positive electrode terminal 22 a and a negative electrode terminal 22 b are attached to the lid portion 22. By connecting an electrical load between these terminals, a current flows through the electrical load.

  FIG. 2 is a perspective view of an electric double layer capacitor cell (hereinafter also referred to as a cell) 10. As shown in FIG. 2, the cell 10 includes a power storage unit 11 and a bag 15 that encloses the power storage unit 11. The bag body 15 is formed by laminating two laminate films (a first film and a second film described later) made mainly of aluminum. The bag body 15 is formed in a flat plate shape so that a rectangular (or square) surface portion 15a and a back surface portion 15b facing each other at a predetermined interval in the vertical direction from the surface portion 15a are formed. Has been.

  The power storage unit 11 includes a positive electrode sheet 11a, a negative electrode sheet 11b, a separator sheet 11c for preventing a short circuit, and an electrolytic solution. The positive electrode sheet 11a and the negative electrode sheet 11b are laminated with the separator sheet 11c interposed therebetween. The positive electrode sheet 11a and the negative electrode sheet 11b are made of, for example, carbon. The separator sheet 11c is a porous sheet. The separator sheet 11c also has a function of holding an electrolytic solution between the positive electrode sheet 11a and the negative electrode sheet 11b. The electrolytic solution is mainly composed of an electrolyte and a solvent. The electrolyte is made of, for example, LiPF6. The solvent is composed of, for example, EC or DEC alone or a mixed solution. Electric double layers are formed at the interface between the positive electrode sheet 11a and the electrolytic solution and at the interface between the negative electrode sheet 11b and the electrolytic solution. Electric charges are stored by forming an electric double layer. A positive electrode current collector terminal (tab terminal) 12a is connected to the positive electrode sheet 11a, and a negative electrode current collector terminal (tab terminal) 12b is connected to the negative electrode sheet 11b. These tab terminals 12 a and 12 b are pulled out from the bag body 15.

  Moreover, the side part formed in the part which connects the periphery side of the surface part 15a of the bag body 15 and the periphery side of the back surface part 15b is comprised by the upper part 15c, the lower part 15d, and the side parts 15e and 15f. Is done. Tab terminals 12a and 12b are drawn out from the upper portion 15c. Moreover, the side parts 15e and 15f form the fin 16, respectively. As is clear from FIG. 2, the fin 16 has a surface parallel to the front surface portion 15a and the back surface portion 15b. Moreover, one fin is formed over the whole area of the up-down direction of each side part 15e, 15f. Furthermore, a plurality of (three in this embodiment) fins are aligned in a direction from the front surface portion 15a toward the back surface portion 15b (a direction substantially perpendicular to the front surface portion 15a and the back surface portion 15b).

  3 and 4 are diagrams showing the manufacturing process of the cell 10. FIG. 3 is a diagram of each process viewed from the upper portion 15 c side of the bag 15 of the cell 10, and FIG. 4 is a diagram of each process viewed from an oblique direction of the cell 10. In FIG. 4, only the steps shown in FIGS. 3A, 3B, 3C, 3D, and 3E are shown.

  In manufacturing the cell 10, first, as shown in FIG. 3A and FIG. 4A, two laminate films (first film 151 and second film 152) are prepared. The first film 151 and the second film 152 are rectangular (or square). The bag body 15 is formed by welding the peripheral portions (four surrounding sides) of the first film 151 and the second film 152 to each other.

  The first film 151 and the second film 152 are generally formed so as to have good thermal conductivity and insulation, and be flexible in a film form. For example, a film (aluminum laminate film) in which an insulating resin is applied to both surfaces of an aluminum film may be the first film 151 and the second film 152.

  FIG. 7 is a partial cross-sectional view of the first film 151 and the second film 152 used in the present embodiment. As shown in FIG. 7, the 1st film 151 and the 2nd film 152 have the aluminum film P which has aluminum as a main component as a base film. An insulating resin layer Q is formed on both surfaces of the aluminum film P. The melting point of the resin constituting the resin layer Q is preferably higher. For example, it is preferable that the resin has a melting point of 200 ° C. or higher and a good insulating property. Further, a welding resin layer R is formed on the insulating resin layer Q formed on one surface. The melting point of the resin constituting the resin layer R should be low. In the present embodiment, the resin constituting the resin layer R is a polypropylene resin having a melting point of about 160 ° C.

  Thus, the welding resin layer R is formed on the outermost side of one surface of the first film 151 and the second film 152, and the resin layer R is not formed on the other surface. The surface on which the resin layer R is formed corresponds to the surface constituting the inner surface of the bag body 15 when both the films 151 and 152 are welded to form the bag body 15. Therefore, the surface on which the resin layer R is formed is referred to as an inner surface IS in this embodiment. On the other hand, the surface on which the resin layer R is not formed corresponds to the surface constituting the outer surface of the bag body 15, and this surface is referred to as an outer surface OS in this embodiment.

  Moreover, as shown in FIG. 3 (A) and FIG. 4 (A), the folding | returning part 151a is formed in 2 sides which oppose among the 4 sides which comprise the peripheral part of the 1st film 151, respectively. Similarly, folded portions 152 a are also formed on two opposing sides among the four sides constituting the peripheral portion of the second film 152. The folded portion 151a (152a) includes a mountain folded portion Y that is folded inward (inward) of the first film 151 (second film 152) in parallel with the side on which the folded portion 151a is formed, and a mountain folded portion Y To the outer side (outside) of the first film 151 (second film 152), and has a valley fold T that is folded back in parallel with the side on which it is formed. A fold line representing the boundary between the mountain fold Y and the valley fold T is substantially parallel to the side where the folded portion 151a (152a) is formed. In this way, the two films 151 and 152 are formed by folding back at least once along the two sides (that is, having one or more valley folds T) on the two opposing sides. 152a) is formed. The number of times of folding of the folded portion 151a (152a) (the number of valley folded portions T) may be any number, but the number of mountain folded portions Y and valley folded portions T is the same. That is, the folded portion 151a (152a) starts with a mountain fold and ends with a valley fold.

  Also, the two folded portions 151a formed on the first film 151 are both formed on the inner surface IS side of the first film 151, and the two folded portions 152a formed on the second film 152 are both It is formed on the inner surface IS side of the second film 152. That is, the mountain fold Y is folded to the inner surface IS side. As described above, the folded portion 151a (152a) starts with a mountain fold and ends with a valley fold. Therefore, when the folded portion 151a (152a) is viewed from the inner surface IS side of the first film 151 (second film 152), The inner surface IS side of the valley fold T that is folded back can be seen.

  The first film 151 and the second film 152 configured as described above are arranged facing each other so that the respective inner surface IS sides face each other (FIGS. 3A and 4A). And the electrical storage body 11 is arrange | positioned between both films (FIG. 3 (B), FIG. 4 (B)). At this time, the power storage unit 11 is arranged so that the positive electrode sheet 11 a and the negative electrode sheet 11 b of the power storage unit 11 are parallel to the first film 151 and the second film 152.

  Next, as shown in FIG. 3C and FIG. 4C, both the films 151 and 152 are brought close to each other so that the power storage unit 11 is sandwiched between the first film 151 and the second film 152, and the first film 151 is formed. The peripheral portion (four sides) of the first film 151 including the folded portion 151a and the peripheral portion (four sides) of the second film 152 including the folded portion 152a formed on the second film 152 are superimposed (overlapping step). ). At this time, the four sides constituting the peripheral portions of both films 151 and 152 are overlapped so that the folded portion 151a formed on the first film 151 and the folded portion 152a formed on the second film 152 are overlapped. Match. 4C, the tab terminals 12a and 12b of the battery 11 are the sides where the folded portions 151a and 152a are not formed among the four sides constituting the peripheral portions of the films 151 and 152. Protrude from.

  Next, as shown in FIG. 3 (D) and FIG. 4 (D), the outer surface OS side is a portion between the mountain fold portion Y and the valley fold portion T of each folded portion 151a of the first film 151. Aluminum (having good thermal conductivity) and the portion between the fold-folded portion Y and the valley-folded portion T of each folded-back portion 152a of the second film 152 and the portion facing the outer surface OS side. A thin metal plate (aluminum bar) 41 having a rectangular cross section made of a material that does not have to be aluminum is sandwiched from the outside (partition plate sandwiching step). Thereby, the mountain fold part Y and the valley fold part T are separated by the aluminum bar 41 over the entire region in the longitudinal direction where the folded parts 151 a and 152 a are formed. In the present embodiment, one folded portion is a portion between the mountain folded portion Y and the valley folded portion T, and the portion facing the outer surface OS side is one location. Therefore, the location where the aluminum bar 41 is sandwiched from the outside is one location for each folded portion. Since the first film 151 has two folded portions 151a and the second film 152 also has two folded portions 152a, there are a total of four locations where the aluminum bar 41 is sandwiched.

  FIG. 8 is an enlarged view of a Z portion in FIG. As shown in FIG. 8, when the aluminum bar 41 is sandwiched from the outside between the mountain fold Y and the valley fold T, the mountain fold Y and valley fold follow the cross-sectional shape (rectangular shape) of the aluminum bar 41. The portion T is deformed into a rectangular shape. By this deformation, the inner surfaces IS of the first film 151 forming the folded portion 151a face each other as shown in the A part of the figure. Moreover, as shown in the B part of the figure, the inner surfaces IS of the second film 152 forming the folded part 152a face each other. Furthermore, as shown in part C of the figure, the inner surface IS of the valley fold T that constitutes the tip of the folded portion 151a of the first film 151 and the valley fold that constitutes the tip of the folded portion 152a of the second film 152 The inner surface IS of T faces each other. That is, by sandwiching the aluminum bar 41, the folded portions 151a and 152a form a state in which the inner surfaces of the same film or the inner surfaces of different films face each other. As shown in FIG. 8, the total thickness of the aluminum bar 41 sandwiched between the folded portion 151 a and the folded portion 152 a is preferably about the same as the thickness of the power storage unit 11. In this case, the thickness of each aluminum bar 41 is preferably about ½ of the thickness of the power storage unit 11. Specifically, it is preferable that the power storage unit 11 has such a thickness that it is not deformed by pressure in a fin forming step described later.

  Subsequently, as shown in FIGS. 3 (E) and 4 (E), the folded portion 151a of the first film 151 and the folded portion 152a of the second film 152 that are overlaid are sandwiched by a pair of heat bars 42, and the predetermined Is applied to both folded portions 151a and 152a. By this pressurization, the inner surfaces IS of the first film 151 facing each other at the folded portion 151a (FIG. 8A portion), and the inner surfaces IS of the second film 152 facing each other at the folded portion 152a (portion of FIG. 8B). And the inner surfaces IS of the folded portions 151a and 152a (the portion in FIG. 8C) that are overlaid are in surface contact. Next, the portions sandwiched between the pair of heat bars 42 are heated to, for example, around 180 ° C. to perform heat welding (fin formation step).

  As described above, the welding resin layer R made of polypropylene resin having a melting point of around 160 ° C. is formed on the outermost surface on the inner surface IS side of both the films 151 and 152. Therefore, when the inner surfaces IS facing each other are heated to around 180 ° C., the polypropylene resin constituting the resin layer R formed on each inner surface is melted, and as a result, the inner surfaces IS facing each other are in close contact with each other. To do.

  After heating by the pair of heat bars 42 for a predetermined time, the heating is stopped and the heat bar 42 is removed (FIG. 3F). Next, the four aluminum bars 41 sandwiched between the mountain fold Y and the valley fold T are removed (FIG. 3G). Note that, as described above, the aluminum bar 41 is sandwiched between portions of the folded portions 151a and 152a between the mountain fold portion Y and the valley fold portion T and facing the outer surface OS side. Since the resin layer R for welding is not formed on the outer surface OS of the both films 151 and 152, and the insulating resin layer Q having a relatively high melting point is formed on the outermost surface, the outermost surface is formed by heat welding. The resin composing the resin layer Q formed in is not melted. Therefore, the aluminum bar 41 does not adhere to both the films 151 and 152 and can be easily removed after heat welding.

  By passing through the above process, as shown to FIG. 3 (G), both the films 151 and 152 are joined by 2 sides which oppose. These joined sides form both side portions 15e and 15f of the bag 15 shown in FIG. The fins 16 are formed on the side portions 15e and 15f by welding the folded portions 151a and 152a of the films 151 and 152 so as to be overlapped with each other.

  Thereafter, of the four sides of the first film 151, the side where the folded portion 151 a is not formed and the tab terminals 12 a and 12 b of the power storage unit 11 are not projected is opposed to the side of the second film 152. Join to the side by heat welding or other means. Thereby, the lower part 15d of the bag body 15 is formed.

  By passing through the above process, the three sides of the bag body 15 are joined, but the remaining one side is not yet joined. Tab terminals 12a, 12b of the power storage unit 11 protrude from between the unjoined sides. An electrolyte is poured into the bag 15 from between the sides. After the injection of the electrolytic solution, the unjoined sides are joined by heat welding or other means. Thereby, the upper part 15c of the bag 15 is formed. Thus, the bag body 15 is formed by bonding the four sides constituting the peripheral portion of the first film 151 and the four sides constituting the peripheral portion of the second film 152 by welding. The electric double layer capacitor cell 10 is manufactured through the above steps.

  In the electric double layer capacitor cell 10 manufactured in this way, the side portions 15e and 15f of the bag body 15 are formed in a fin shape as shown in FIG. That is, the side portions 15 e and 15 f of the bag body 15 form the fins 16. In the present embodiment, three fins are formed on the respective side portions along the direction from the front surface portion 15a to the back surface portion 15b of the bag body 15. As described above, since the fins 16 are formed at the same time when the cells 10 are manufactured, productivity is improved as compared with the case where the fins are separately attached to the cells 10.

  After producing a plurality of electric double layer capacitor cells 10 as described above, the electric double layer capacitor module 1 is produced using the plurality of electric double layer capacitor cells 10. 5 and 6 are diagrams showing the manufacturing process of the electric double layer capacitor module 1. FIG. 5 is a diagram of each process viewed from above the electric double layer capacitor module 1, and FIG. 6 is a diagram of each process viewed from an oblique direction of the electric double layer capacitor module 1. FIG. 5 shows only the steps shown in (I) and (J) of FIG.

  In manufacturing the electric double layer capacitor cell, first, as shown in FIG. 6 (H), a plurality of cells 10, a heat sink 30 for sandwiching between the cells 10, an inter-cell connection component 51, and two sheets Cell holding plate 60 is prepared.

  Next, as shown in FIG. 5 (I) and FIG. 6 (I), the plurality of cells 10 are aligned so that the front surface portions 15a of the bag body 15 of each cell 10 face each other and the back surface portions 15b face each other. Let Further, a heat radiating plate 30 is disposed between adjacent cells 10. Thereafter, both ends in the alignment direction of the cells 10 are sandwiched between the cell pressing plates 60. Thereby, the stacked body S in which the plurality of cells 10 are stacked is formed. In the laminated body S, the tab terminals 12a and tab terminals 12b drawn from the bags of the cells 10 are alternately arranged, and the fins 16 formed on the side portions 15e and 15f of the bags 15 are the same. The cells 10 are stacked so as to be arranged in the direction.

  Next, as shown in FIGS. 5 (J) and 6 (J), the stacked body S is accommodated in the container portion 21 of the housing 20 (accommodating step). At this time, the laminated body S is accommodated in the container part 21 so that the upper part of the bag body 15 of each cell 10 (the part from which the tab terminals 12 a and 12 b are pulled out) faces the opening surface of the container part 21. Further, as shown in FIG. 5 (J), an elastic force generating device 70 is accommodated in the container portion 21, and this elastic force generating device 70 is arranged on one end side of the laminated body S. Is pressed to the other end side of the laminate S. As a result, a predetermined pressing force is applied to the laminate S.

  Also, the illustrated lateral width W1 of the internal space of the container portion 21 shown in FIG. 5 (J) is equal to or slightly smaller than the width W2 between the side portions of the cell 10 shown in FIG. 5 (I) (W1 is W2). Is preferably slightly smaller). Therefore, when the laminated body S is accommodated in the container portion 21, the fins 16 formed on both side portions 15 e and 15 f of the bag body 15 of each cell 10 come into contact with the inner wall of the container portion 21. In this case, since the fin 16 is formed of a flexible aluminum laminate film, the tip of the fin 16 comes into contact with the inner wall of the container portion 21 and is bent. Thereby, it is prevented that the laminated body S cannot be accommodated in the container part 21 by interference with the fin 16 and the container part 21. Further, the fins 16 are surely in contact with the inner wall of the container part 21 only by roughly setting the width dimension of the cell so that the fins 16 are always in contact with the inner wall of the container part 21 and bent. Therefore, when the cell 10 generates heat, the heat is quickly transmitted from the fins 16 to the container part 21 and further rapidly radiated from the container part 21 to the outside. Further, as shown in FIG. 5J, all the fins 16 are aligned at equal intervals by making the thickness of the heat dissipation plate 30 in the stacking direction equal to the distance between adjacent fins.

  After the laminated body S is accommodated in the container part 21, the tab terminal (positive electrode current collecting terminal) 12a and the tab terminal (negative electrode current collecting terminal) 12b of the adjacent cells 10 in the laminated body S are connected to each other. Join with. This joining is performed by mechanical fastening, ultrasonic welding, resistance welding, or the like. Thereby, each cell 10 is connected in series. Next, the lid portion 22 is placed over the opening of the container portion 21, and the container portion 21 and the lid portion 22 are joined. The lid portion 22 is provided with a positive electrode terminal 22a and a negative electrode terminal 22b. When the container portion 21 and the lid portion 22 are joined, the tab terminal of the cell 10 disposed at one end of the stacked body S. (Positive electrode current collecting terminal) 12a is connected to positive electrode terminal 22a, and tab terminal (negative electrode current collecting terminal) 12b of cell 10 arranged at the other end is connected to negative electrode terminal 22b. The electric double layer capacitor module 1 of the present embodiment is manufactured through the above steps.

(Modification)
9 and 10 are process diagrams showing a method for manufacturing an electric double layer capacitor cell according to a modification of the embodiment. In the above embodiment, the folded portions 151a and 152a are formed on both the first film 151 and the second film 152, respectively, but in the present modification, the folded portion 151a is formed only on the first film 151. In addition, the folded portion is not formed on the second film 152. Using such two films, the electric double layer capacitor cell of the present invention can also be produced.

  Briefly, in manufacturing an electric double layer capacitor cell, first, two laminate films (first film 251 and second film 252) are prepared. The 1st film 251 is rectangular shape, and the folding | returning part 251a is formed in two opposing sides. On the other hand, the second film has the same shape (rectangular shape) as the first film 251, but the folded portion is not formed on the two opposing sides. Both films are formed of the same material as the first film 151 and the second film 152 described in the above embodiment. Then, the two prepared films are arranged to face each other so that the inner surfaces IS face each other (FIGS. 9A and 10A).

  Next, the power storage unit 11 is placed between the two films (FIGS. 9B and 10B). Subsequently, both the films 251 and 252 are brought close to each other so that the power storage unit 11 is sandwiched between the first film 251 and the second film 252, and the second film 251 a and the peripheral portion of the first film including the folded portion 251 a are formed. The peripheral part of the film is overlaid (FIG. 9C, FIG. 10C: superposition step).

  Next, the aluminum bar 41 is sandwiched between portions of the folded portions 251a of the first film 251 between the mountain fold portion Y and the valley fold portion T and facing the outer surface OS side (FIG. 9D, FIG. 10D: Partition plate sandwiching step).

  Subsequently, the folded portion 251a of the first film 251 and the peripheral portion of the second film 252 are sandwiched by the heat bar 42 for heat welding, and a predetermined pressure is applied (FIGS. 9E and 10E). )). Next, heat welding is performed by heating the portion sandwiched between the heat bars 42 (fin formation step). By this heat welding, two opposing sides of the first film 251 and the second film 252 are joined, and both side portions 15e and 15f of the bag body 15 are formed. Further, the folded portion 251 a is welded to the peripheral portion of the second film 252, whereby the fins 16 are formed on the side portions 15 e and 15 f of the bag body 15.

  Since the process after the above-described process is the same as the process described in the above embodiment, the detailed description thereof is omitted. FIG. 11 is a diagram illustrating the cell 10 manufactured by the above-described process, in which (a) is a top view of the cell 10 and (b) is a perspective view of the cell 10.

  As shown in FIG. 11, two fins 16 are formed on both side portions 15 e and 15 f of the bag body 15 of the cell 10 manufactured according to this example from the front surface portion 15 a to the back surface portion 15 b of the bag body 15. The In addition, in order to form the three fins 16 as in the above embodiment, the folded portion 251a of the first film 251 may be formed by being folded twice (that is, it may be folded twice).

  As described above, the electric double layer capacitor module 1 of the present embodiment accommodates the electric double layer capacitor cell 10 including the power storage unit 11 and the bag body 15 enclosing the power storage unit 11, and the cell 10 therein. The housing 20 is provided. The bag 15 includes a front surface portion 15a, a back surface portion 15b facing the front surface portion 15a, and side portions (an upper portion 15c, a lower portion 15d, both sides formed between the front surface portion 15a and the back surface portion 15b. A plurality of fins 16 having side surfaces 15e and 15f) aligned in the direction from the front surface portion 15a to the back surface portion 15b and parallel to the front surface portion 15a and the back surface portion 15b. Form. Therefore, the heat generated in the power storage unit 11 in the bag body 15 is dissipated to the outside through the fins 16 formed in the bag body 15 itself. For this reason, the heat dissipation efficiency is improved.

  Further, heat can be efficiently radiated through the fins 16 formed on the bag body 15 itself of the cell 10 without attaching an exhaust fan to the housing 20. Therefore, the electric double layer capacitor module 1 can be configured in a compact manner. Further, since it is not a structure that needs to be exposed to the outside, the usage is not particularly limited by the limitation of the installation location. Furthermore, since special dimensional accuracy is not required, productivity does not deteriorate. Thus, according to this embodiment, it is possible to provide an electric double layer capacitor module with improved heat dissipation efficiency and less adverse effects.

  Moreover, the bag body 15 is comprised with the flexible film, and the fin 16 is in contact with the inner wall of the container part 21 of the housing 20 as it shows well in FIG. Therefore, the heat of the fins 16 is quickly transmitted to the housing 20 side, and is further quickly radiated from the housing 20 to the outside. Therefore, the heat dissipation efficiency is further improved. Moreover, since the bag body 15 is comprised with the flexible film, the fin 16 is also formed with a flexible film. Therefore, even if the dimensions of the fins 16 vary, the variation in dimensions is absorbed by bending when the tips of the fins 16 come into contact with the inner wall of the container portion 21. Therefore, it is not necessary to strictly manage the dimensions of the fins 16, and as a result, productivity is improved.

  Moreover, the bag body 15 is formed by welding the four sides constituting the peripheral portions of the flexible first film 151 (251) and the second film 152 (252) each having a rectangular shape. Moreover, the folding | returning part 151a (251a) formed by folding twice or more along the edge | side is provided in 2 sides which oppose among the 4 sides which comprise the circumference part of the 1st film 151 (251). The fin 16 is formed by welding the folded portion 151a (251a) to the peripheral portion of the second film 152 (252). In this manner, the fins 16 can be easily formed on the side portions of the bag body 15.

  In addition, the electric double layer capacitor cell manufacturing method according to the present embodiment has a rectangular shape, and is folded back twice or more along the two sides of the four sides constituting the periphery thereof. Between the flexible first film 151 (251) provided with the folded portion 151a (251a) and the rectangular flexible second film 152 (252). 11 in a state in which the peripheral portion of the first film 151 (251) including the folded portion 151a (251a) and the peripheral portion of the second film 152 (252) are overlapped with each other, and the first overlapped portion 151a (251a). The folded portion 151a (251a) is provided by welding the folded portion 151a (251a) of the film 151 (251) to the peripheral portion of the second film 152 (252). The portion being comprising a fin forming step of forming a fin 16. Furthermore, the manufacturing method of the electric double layer capacitor cell according to the present embodiment provides the second side where the folded portion 151a (251a) is not formed among the four sides constituting the peripheral portion of the first film 151 (251). It includes a step of forming the bag 15 by bonding to the periphery of the film 152 (252) by welding or the like.

  By manufacturing the electric double layer capacitor cell 10 through the above steps, it is possible to easily manufacture the electric double layer capacitor cell 10 in which a part of the side portion of the bag body 15 has a fin shape.

  Further, on the inner surface IS side of the folded portion 151a (251a) of the first film 151 (251), a resin that melts when the folded portion 151a (251a) is welded to the peripheral portion of the second film 152 (252). A layer R (for example, polypropylene resin) is formed. Therefore, when the folded portion 151a (251a) is welded around the second film 152 (252), the resin constituting the resin layer R formed on the inner surface IS side of the folded portion 151a (251a) is melted. By doing so, inner surface IS side of the folding | returning part 151a (251a) closely_contact | adheres. For this reason, a thin fin can be formed on the side portion of the bag body 15.

  Moreover, the manufacturing method of the electric double layer capacitor cell according to the present embodiment has an outer side between the mountain fold portion Y and the valley fold portion T formed in the folded portion 151a (251a) of the first film 151 (251). A partition plate sandwiching step of sandwiching a flat partition plate (aluminum bar 41). By providing the partition plate sandwiching step, the heat applied in the fan forming step that is performed thereafter can be evenly transmitted to the entire area of the folded portion 151a (251a). For this reason, the 1st film 151 (251) and the 2nd film 152 (252) are welded reliably, and the bag body 15 which the electrolyte solution with which an inside is filled does not leak can be formed. In addition, by uniformly melting the polypropylene resin constituting the welding resin layer R formed on the inner surface IS side of the folded portion 151a (251a), the entire region in the longitudinal direction of the side portions 15e and 15f of the bag body 15 is obtained. The fins 16 having a uniform width can be formed.

  Moreover, the manufacturing method of the electric double layer capacitor module according to the present embodiment includes a stacked body S by stacking a plurality of electric double layer capacitor cells 10 manufactured by the method of manufacturing an electric double layer capacitor cell including the steps described above. The laminated body S is accommodated in the housing 20 so that the fins 16 formed in the cells 10 constituting the laminated body S are in contact with the inner wall of the container portion 21 of the housing 20. A containment process.

  By manufacturing the electric double layer capacitor module 1 through the above steps, the heat of the fins 16 is quickly transmitted to the housing 20 side, and further quickly radiated from the housing 20 to the outside. Therefore, the heat dissipation efficiency is further improved. Moreover, since the bag body 15 is comprised with the flexible film, the fin 16 is also formed with a flexible film. Therefore, even if the dimensions of the fins 16 vary, the variation in dimensions is absorbed by bending when the tips of the fins contact the body wall. Therefore, it is not necessary to strictly manage the fin dimensions, and as a result, productivity is improved.

  As mentioned above, although embodiment of this invention was described, this invention should not be limited to the said embodiment. For example, although the said embodiment demonstrated the electric double layer capacitor module, its manufacturing method, and the manufacturing method of an electric double layer capacitor cell, the cell provided with the electrical storage body and the bag body which encloses an electrical storage body, and this cell are accommodated. If it is an electrical storage device provided with a housing, this invention can be applied. For example, the present invention can be applied to a secondary battery such as a lithium ion battery. Moreover, although the said embodiment demonstrated the example in which three or two fins are formed in the both sides of one cell, if the number of the fins formed is plural, it does not ask | require. Moreover, in the said embodiment, although the example which formed the bag body 15 with the film by which resin was apply | coated to the surface of an aluminum film was shown, it has various functions (insulation) which has flexibility and encloses an electrical storage body. Etc.) and any material that can be joined by welding. Thus, the present invention can be modified without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 ... Electric double layer capacitor module, 10 ... Electric double layer capacitor cell, 11 ... Electric power storage body, 15 ... Bag body, 15a ... Front surface part, 15b ... Back surface part, 15c ... Upper part, 15d ... Lower part, 15e, 15f ... Side part, 151,251 ... first film, 151a, 251a ... folded part, 152,252 ... second film, 152a ... folded part, 16 ... fin, 20 ... container, 21 ... container part, 22 ... lid part, 30 ... Radiating plate, 41 ... Aluminum bar, 42 ... Heat bar, IS ... Inner surface, OS ... Outer surface, S ... Laminate, T ... Valley fold, Y ... Mountain fold

Claims (7)

An electrical storage device comprising an electrical storage body and an electrical storage cell comprising a bag enclosing the electrical storage body, and a housing for housing the electrical storage cell therein,
The bag body includes a surface portion, a back surface portion facing the surface portion, and a side portion formed between the surface portion and the back surface portion,
At least a part of the side part is aligned in a direction from the front surface part toward the back surface part, and forms a plurality of fins having surfaces parallel to the front surface part and the back surface part. The electricity storage device according to claim 1,
The bag is made of a flexible film;
The power storage device, wherein the fin is in contact with an inner wall of the housing. The electricity storage device according to claim 1 or 2,
The bag body is formed by welding four sides constituting the peripheral portions of each of the flexible first film and the second film which are rectangular,
Folding portions formed by folding one or more times along the sides are provided on two opposing sides of the four sides constituting the peripheral portion of the first film,
The said fin is an electrical storage device formed by welding the said folding | turning part of the said 1st film to the surrounding part of the said 2nd film. The electricity storage device according to any one of claims 1 to 3,
A power storage device in which a plurality of the power storage cells are stacked in the casing. A method of manufacturing a power storage cell including a power storage unit and a bag body enclosing the power storage unit,
A flexible first having a rectangular shape and a folded portion formed by being folded at least once along two sides of two sides of the four sides constituting the peripheral portion. A peripheral portion of the first film including the folded portion and a peripheral portion of the second film in a state where the power storage unit is sandwiched between the film and a flexible second film having a rectangular shape. A superposition process for superimposing;
A fin forming step of forming fins in the portion where the folded portion is provided by welding the folded portion of the first film overlapped to the peripheral portion of the second film;
The manufacturing method of an electrical storage cell containing this. In the manufacturing method of the electrical storage cell according to claim 5,
The folded portion is formed with a mountain folded portion in which the first film is folded inward in parallel to a side on which the folded portion is formed, and from the mountain folded portion toward the outside of the first film. And a valley fold that is folded back parallel to the side
A partition plate sandwiching step of sandwiching a flat partition plate between the mountain fold portion and the valley fold portion;
The said fin formation process is a manufacturing method of an electrical storage cell implemented after the said superimposition process and the said partition plate clamping | pinching process. An electrical storage device comprising an electrical storage body and an electrical storage cell comprising a bag body enclosing the electrical storage body, and a housing for housing the electrical storage cell therein,
A laminate forming step of forming a laminate by laminating a plurality of the electricity storage cells manufactured by the method for manufacturing an electricity storage cell according to claim 5 or 6,
A housing step of housing the multilayer body in the housing such that fins formed in the storage cells constituting the multilayer body are in contact with an inner wall of the housing;
A method for manufacturing an electricity storage device, comprising:

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