JP2012104225A - Battery module, method of manufacturing battery module and spacer for battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer for battery having a simple structure and a high cooling efficiency, and to provide a battery module equipped with it and a method of manufacturing a battery module.SOLUTION: The spacers (3) consisting of a plurality of rodlike members (31) which can be attached detachably to a comb-shaped jig (7) are arranged in parallel, at an equal pitch, between unit cells (2) and a space surrounded by adjoining rodlike members (31) and adjoining unit cells (2) is formed as a flow path (32) for cooling medium. When the cooling medium passes through the flow path (32) for cooling medium, the cooling medium comes into direct contact with the unit cells (2) on both sides thus cooling the unit cells (2) efficiently.

Description

  The present invention relates to a battery module, a battery module manufacturing method, and a battery spacer, and more particularly, to a battery module formed by stacking a plurality of unit cells, a manufacturing method thereof, and a battery spacer disposed between stacked unit cells.

  Various battery modules formed by laminating a plurality of unit batteries have been conventionally proposed. This type of battery module is used in various applications ranging from electrical products to hybrid vehicles, railway vehicles, and microgrid systems. In particular, in hybrid vehicles, railway vehicles, microgrid systems, etc., battery modules are required to have high output and large capacity. Therefore, such battery modules have high energy density, such as nickel metal hydride batteries and lithium ion batteries. Is used.

  On the other hand, since these nickel hydride batteries and lithium ion batteries pass a large current, the batteries may generate heat and become high temperature. In particular, when used in railway vehicles, microgrid systems, etc., the battery becomes large, so a large battery module in which such large batteries are stacked has been proposed to employ a cooling structure for cooling the battery. Yes.

  As this type of prior art, there has been proposed a cooling structure in which a plurality of air flow paths penetrating in the vertical direction are provided, and a heat radiating partition plate having a nickel-plated surface is used as a conductive material (for example, Patent Documents) 1).

  As another prior art, a secondary battery module has been proposed in which a heat radiating plate having a cooling medium channel provided on one side or both sides of a metal plate is disposed between stacked unit cells (for example, Patent Document 2). ). The secondary battery module of Patent Document 2 includes a heat dissipation plate that can directly cool the unit battery with a cooling medium.

Japanese Patent Laying-Open No. 2008-171628 (see FIGS. 1 and 4) Japanese Patent Laying-Open No. 2006-278330 (see FIGS. 1, 3 and 5)

  However, since the heat dissipation partition plate of Patent Document 1 is formed by extrusion integral molding (hereinafter referred to as integral molding) with a metal material such as aluminum having a shape having a large number of hollow portions as distribution channels, the manufacturing cost is high. Furthermore, since the entire surface and the inside of the hollow part are plated with nickel, the manufacturing cost is further increased.

  In addition, the heat dissipation partition plate of Patent Document 1 first cools the heat dissipation partition plate with a cooling medium passing through the flow path, and cools the battery with the cooled heat dissipation partition plate. In other words, since the battery is indirectly cooled through the heat radiating partition plate, the cooling efficiency is low as compared with the case of directly cooling the battery.

  On the other hand, since the heat radiating plate of Patent Document 2 is integrally molded, there is a problem similar to that of the heat radiating partition plate of Patent Document 1. In addition, this heat radiating plate can directly cool one or both unit cells with a cooling medium, but a base material for forming a cooling medium flow path (cooling channel) (a semicircle on the left side of FIG. 3 of Patent Document 2). The part without a notch, the base part in the center of FIG. 5 is an essential configuration. When the size of the battery module as a whole is reduced, the substrate portion must also be reduced. However, it may be difficult to reduce the size of the substrate portion due to the structure. Furthermore, the cooling medium not only cools the unit battery, but also cools the base member, and the cooling efficiency of the unit battery is reduced accordingly.

As described above, the heat dissipating plate (heat dissipating partition plate or heat dissipating plate) disclosed in Patent Document 1 or 2 has room for improvement in the following points.
(1) It is an integrally formed heat dissipation plate having a complicated cross-sectional structure, which requires manufacturing costs.
(2) Since the battery is indirectly cooled via the heat radiating plate, the cooling efficiency is reduced as compared with the case where the battery is directly cooled.
(3) When the base material portion is an essential configuration and the size of the entire battery module is reduced, the thickness of the base material portion and its presence may hinder the battery module from being downsized. Further, the cooling medium also cools the base material portion that is not directly related to the cooling of the unit battery.

  The present invention has been made in view of the above points, and provides a battery module having a low cost and high cooling efficiency, a battery module manufacturing method, and a battery spacer by using a heat sink having a simple structure as a spacer. With the goal.

  In order to solve the above problems, the battery module according to the present invention is a battery module in which a plurality of unit cells are stacked and a spacer is disposed between adjacent unit cells, and the spacer is a plurality of rods extending in a predetermined direction. The rod-shaped member is sandwiched between two unit batteries that are in contact with the front and rear in the stacking direction, and the adjacent rod-shaped member is formed as a cooling medium flow path.

  According to this configuration, a plurality of bar-shaped members having a simple structure are arranged with a space between each unit cell, so that a space surrounded by the adjacent unit cells and the adjacent bar-shaped member is formed as a flow path for the cooling medium. Can be formed as Moreover, since the cooling medium directly contacts the unit cell, the cooling efficiency is high.

Here, the terms are briefly described below.
-“Lamination direction” refers to the direction in which unit cells are laminated.
“Cooling medium” refers to a fluid for cooling the unit battery, and refers to a gas such as air or a liquid such as silicon oil, electrical insulating oil, or PCB oil.

  The battery module according to claim 2 is characterized in that the unit cell has a front surface in the stacking direction having either one of a positive electrode and a negative electrode, a rear surface having the other electrode, and the rod-shaped member is conductive. To do.

  According to this configuration, when the unit battery in which the front and rear surfaces of the unit cell in the stacking direction are formed of a positive electrode plate and a negative electrode plate is used, each unit cell is electrically connected if the rod-shaped member is conductive. Can be easily done. That is, the unit cells can be electrically connected by abutting the opposing positive and negative electrode plates of the adjacent unit cells.

  In the battery module according to claim 3, the spacer is held by a comb-like jig to which the rod-shaped members can be attached and detached before being fixed between the unit cells, and after being fixed between the unit cells. The comb-shaped jig is removed.

  According to this configuration, before fixing to the unit battery, each bar-shaped member constituting the spacer is held by the upper and lower comb-shaped jigs, and a plurality of bar-shaped members can be integrally disposed between the unit cells. Since it can do, arrangement | positioning of a spacer is easy. Then, after fixing the spacers between the unit cells, by removing the comb-shaped jig, it is possible to easily fix the rod-shaped members as the spacers at predetermined positions. Here, the “comb-shaped jig” refers to a comb-shaped jig having a plurality of comb teeth protruding on one side, and a rod-shaped member is held between the comb teeth.

  In addition, as a material of a comb-shaped jig | tool, what can hold | maintain a rod-shaped member and can attach or detach a rod-shaped member is preferable. As such a material, synthetic rubber, polypropylene, polyethylene, silicon rubber, or the like can be used.

  In the battery module according to a fourth aspect, it is preferable that an axial cross section of the rod-shaped member has a rectangular shape.

  According to this configuration, the rod-shaped member can be easily installed on the unit battery and can be firmly fixed to the unit battery.

  In the battery module according to a fifth aspect, the rectangular shape is preferably a square or a rectangle whose side parallel to the stacking direction is shorter than the other side.

  According to this configuration, when the rod-shaped member is installed in the unit battery, the rod-shaped member is unlikely to fall down even when a lateral force is generated on the rod-shaped member. In short, the axial cross section of the rod-shaped member can be made to be a rod-shaped member resistant to shearing force by setting the length of the side parallel to the stacking direction to be equal to or less than the length of the other side (square or long rectangle).

  In the battery module according to claim 6, at least a part of the rod-shaped member may be formed of a plate material having a corrugated cross section in the stacking direction.

  According to this configuration, in the stacking direction of the unit cells, the cross-section of the rod-shaped member is corrugated and hardly falls down sideways. Further, since the surface area of the rod-shaped member is increased, the area in contact with the cooling medium is also increased, and cooling of the rod-shaped member is promoted. Furthermore, the area of the cross section in the stacking direction is increased, and the electrical conductivity is increased.

  In the battery module according to a seventh aspect, it is preferable that the rod-shaped members are arranged in parallel at equal pitches between the unit cells.

  According to this configuration, the rod-shaped member can be easily arranged, the cooling medium flow path can be formed uniformly, and the entire unit battery can be cooled uniformly.

  In the battery module according to an eighth aspect, the arrangement of the rod-shaped members may be wider in the central portion than the pitch in the both end portions of each unit battery.

  According to this configuration, the area where the central portion of the unit battery contacts the cooling medium is larger than both end portions, and the central portion can be actively cooled. In general, heat is easily released at both ends of the battery, and heat is easily accumulated at the center.

  The battery module according to claim 9 may have a shape in which a cross section in the stacking direction of the rod-shaped member swells from both ends to the center.

  According to this configuration, the rod-shaped member has a rod shape that swells from both ends to the center, and is less likely to fall sideways. On the other hand, since the cooling medium flow path has a narrow central portion, the flow rate of the cooling medium is increased when the cooling medium passes through the central portion, and the battery can be further cooled.

  In the battery module according to claim 10, the unit battery may be a nickel metal hydride battery.

  According to this configuration, the unit battery has a high energy density and can be a high output battery module.

  The battery manufacturing method according to claim 11 is a method of manufacturing a battery module in which a plurality of unit cells are stacked, and includes the unit battery and a plurality of rod-like members fitted in advance to a comb-like jig. Stacking spacers to form unit cell assemblies, pressing the unit cell assemblies in the stacking direction, pressing unit cell assemblies in the stacking direction via the compression plates at both ends, And a step of pressing the unit battery assembly, and a step of removing the comb-shaped jig from the rod-shaped member after pressing the unit battery assembly.

  According to this configuration, a plurality of bar-shaped members having a simple structure are arranged with a space between each unit cell, so that a space surrounded by the adjacent unit cells and the adjacent bar-shaped member is formed as a flow path for the cooling medium. The battery formed as can be easily manufactured. Specifically, since the end portions of the rod-shaped members constituting the spacer are held by the comb-shaped jig before pressing the unit cell assembly, the spacer can be easily handled and arranged. Then, after pressing the unit cell assembly to fix the spacers between the unit cells, the comb-shaped jig is removed, so that each rod-like member as the spacer can be easily arranged at a predetermined position. Moreover, since the cooling medium directly contacts the unit cell, the cooling efficiency is high.

  A battery manufacturing method according to claim 12 is a method of manufacturing a battery module in which a plurality of unit batteries are stacked, and includes the unit battery and a plurality of rod-shaped members fitted in advance to a comb-like jig. A step of stacking spacers to form a unit cell assembly, and a step of arranging sandwiching plates for sandwiching the unit cell assembly from both sides at both ends of the unit cell assembly in the stacking direction. The cross-section in the stacking direction of the sandwich plate is larger in the lateral direction than the same cross section of the unit cell, and through holes for inserting bolts are provided on both sides of the sandwich plate. A step of pressing the unit cell assembly in the stacking direction via a plate; and after pressing the unit cell assembly, the bolt is communicated between the sandwiching plates disposed at both ends in the stacking direction, Stack the stacking direction A step of fastening the clamping plates at both ends with the bolt so as to be clamped from an end; and a step of removing the comb-shaped jig from the rod-shaped member after the bolt and the clamping plate are fastened. , Provided.

  According to this configuration, the same effect can be expected for a battery having a configuration different from that of claim 11.

  In the battery manufacturing method according to a thirteenth aspect, the comb-shaped jig is preferably flexible.

  According to this configuration, by making the comb-like jig flexible, the rod-shaped member can be held and the rod-shaped member can be easily attached and detached.

  In the battery manufacturing method according to a fourteenth aspect, it is preferable that the tip of the comb tooth portion of the comb-shaped jig is formed with an acute angle or a rounded shape.

  According to this configuration, when the rod-shaped member is fitted along the longitudinal direction between the comb-tooth portions of the comb-shaped jig, the rod-shaped member is guided and can be fitted smoothly.

  The battery manufacturing method according to claim 15 may be formed by chamfering a peripheral corner portion of a comb tooth portion of the comb-like jig.

  According to this configuration, when the rod-shaped member is fitted along the thickness direction between the comb-tooth portions of the comb-shaped jig, the rod-shaped member is guided and can be fitted smoothly.

  The battery spacer according to claim 16 is a battery spacer that is provided between adjacent unit cells of a battery in which a plurality of unit cells are stacked, and forms a cooling medium flow path for cooling the unit cells. The rod-shaped member is sandwiched between the two unit cells that are in contact with the front and rear in the stacking direction, and the adjacent rod-shaped member is used as the cooling medium flow path. It is characterized by using.

  According to this configuration, a plurality of bar-shaped members having a simple structure are arranged with a space between each unit cell, so that a space surrounded by the adjacent unit cells and the adjacent bar-shaped member is formed as a flow path for the cooling medium. Can be formed as Moreover, since the cooling medium directly contacts the unit cell, the cooling efficiency is high.

  The battery spacer according to claim 17 is characterized in that the rod-shaped member is conductive.

  The spacer for a battery according to claim 18, wherein the spacer is held by a comb-like jig to which the rod-shaped member is detachable before being fixed between the unit batteries, and after being fixed to the unit battery, The comb-shaped jig is removed.

  In the battery spacer according to claim 19, it is preferable that the rod-shaped members are arranged in parallel at an equal pitch between the unit batteries.

  In the battery spacer according to claim 20, it is preferable that the comb-shaped jig is flexible.

As described above, the battery module, the battery module manufacturing method, and the battery spacer according to the present invention have the following excellent effects.
-The cooling efficiency of the battery can be improved by using a spacer having a simple structure, and the cost can be reduced.
-Since the battery is directly cooled by the cooling medium, the cooling efficiency is increased.
-The base material part for connecting each rod-shaped member is unnecessary, and a battery can be reduced in size. Further, since the cooling medium does not cool the substrate portion, the cooling efficiency is increased.

It is a perspective view of the battery module which concerns on embodiment of this invention. (A) is a front view of a state in which a spacer is fitted in a comb-like jig. (B) is a top view of the state which connected the same spacer to the unit battery. (C) is the perspective view which expanded the spacer edge part partially. (A), (b) is a front view which shows the modification which changed the shape of the rod-shaped member of a spacer in the battery module which concerns on embodiment of this invention. (A)-(d) is a figure which shows the modification which changed the comb-tooth part shape of the comb-shaped jig | tool in the battery module which concerns on embodiment of this invention. It is a perspective view which shows the flow of the cooling medium (air) in the spacer in the battery module which concerns on embodiment of this invention. It is a top view which shows the flow direction of the heat | fever in the unit battery in the battery module of FIG. It is a perspective view of the cooling unit which cools with the forced cooling fan and wind tunnel which are attached to the battery module which concerns on embodiment of this invention. (A)-(c) is a front view which shows the modification which changed the shape and arrangement | positioning of the rod-shaped member of a spacer in the battery module which concerns on embodiment of this invention. It is a perspective view which shows the manufacturing process of the battery module which concerns on embodiment of this invention. It is a perspective view which shows the manufacturing process of the modification of the battery module which concerns on embodiment of this invention.

  Embodiments of a battery module, a battery module manufacturing method, and a battery spacer according to the present invention will be described below with reference to the drawings. The present invention is not limited to the following embodiment.

[Configuration of battery module]
As shown in FIG. 1, the battery module 1 includes a unit battery 2, a spacer 3, a compression plate 4, a side plate 5, and a reinforcing plate 6 as main components. Specifically, the unit battery 2 and the spacer 3 are alternately stacked to form a unit battery assembly 11, and a current collector plate, an insulating plate, and a compression support plate (not shown) are provided at both ends of the unit battery assembly 11. The battery plate 1 is configured by covering the left and right side surfaces with side plates 5 and the upper and lower surfaces with reinforcing plates 6. In the present embodiment, the stacking direction in which the unit cells 2 and the like are stacked is the X direction in FIG.

・ Unit battery 2
The unit battery 2 is a sealed nickel-metal hydride battery. As shown in FIG. 6, the unit cell 2 is provided with a positive electrode current collector 21 and a negative electrode current collector 23 made of a metal having good conductivity before and after the stacking direction X. Between the positive electrode current collector 21 and the negative electrode current collector 23, bellows-like separators 25 that transmit ions but do not transmit electrons are alternately arranged so as to be close to both current collectors. And a negative electrode part. In each space formed by the separator 25 and the positive electrode current collector 21, the positive electrode sheet 22 containing the positive electrode active material together with the electrolyte solution is disposed, and is partitioned by the separator 25 and the negative electrode current collector 23. The negative electrode sheet 24 containing the negative electrode active material together with the electrolyte solution is disposed in the space, and the positive electrode sheet 22 and the negative electrode sheet 24 are alternately incorporated with the separator 25 interposed therebetween. The positive electrode current collector 21 and the negative electrode current collector 23 are in contact with the positive electrode sheet 22 and the negative electrode sheet 24, respectively, and constitute a positive electrode and a negative electrode, respectively. Therefore, each unit battery 2 can be electrically connected by stacking each unit battery 2 so that the positive electrode current collector 21 and the negative electrode current collector 23 face each other. Alternatively, a conductive spacer (bar-shaped member 31) may be interposed.

  In this embodiment, for example, the positive electrode sheet 22 is formed into a plate by applying a paste to a positive electrode active material, a conductive filler (conductive material), and a resin by adding a solvent. , Cured. The negative electrode sheet 24 is obtained by, for example, applying a paste obtained by adding a solvent to a negative electrode active material, a conductive filler, and a resin, forming the paste on a substrate, and then curing it.

  As the positive electrode active material and the negative electrode active material, all known active material materials can be used. As the conductive filler, carbon fiber, carbon fiber nickel-plated, carbon particles, carbon particle nickel-plated, organic fiber nickel-plated, fibrous nickel, nickel particles, nickel foil, etc. alone or in combination Can be used. Examples of the resin include thermoplastic resins having a softening temperature of 120 ° C., resins having a curing temperature from room temperature to 120 ° C., resins that dissolve in a solvent having an evaporation temperature of 120 ° C. or less, resins that dissolve in a solvent soluble in water, and alcohol. Resins that are soluble in a soluble solvent can be used. As the substrate, a conductive metal plate such as an aluminum plate, a nickel-plated aluminum plate, or a nickel plate can be used.

・ Spacer 3
As shown in FIG. 2A, the spacer 3 according to this embodiment includes a conductive rod-shaped member 31. The rod-shaped member 31 can be made of a conductive material such as an aluminum material, a nickel-plated aluminum material, or a nickel material. Before fixing to each unit battery 2, the upper and lower ends of the rod-shaped member 31 are held by the pair of comb-shaped jigs 7. And after fixing between each unit battery 2, the comb-shaped jig | tool 7 is extracted from the rod-shaped member 31, and the rod-shaped member 31 can be arrange | positioned in parallel with each unit cell 2 at equal pitch.

  In the present embodiment, the rod-shaped members 31 extending in the height direction of the unit battery 2 are arranged at an equal pitch in the lateral direction of the unit battery 2. However, the present invention is not limited to this. You may arrange | position the rod-shaped member extended | stretched to the horizontal direction at equal pitch in the height direction of the unit battery 2. FIG.

  The spacer 3 is handled as one component in an assembled state in which the bar-shaped member 31 is fitted in the comb-shaped jig 7 in advance. If it carries out like this, when unit battery 2 is laminated | stacked, it will be easy to pinch | interpose and work cost can be held down. In addition, the comb-like jig 7 can be used by fitting the rod-like member 31 again after use, and can be recycled. Therefore, the material cost can be suppressed.

  Further, even when the design change occurs in the spacer 3 as a result of the design change in the battery module 1 or the unit battery 2 shown in FIG. 1, the arrangement of the rod-shaped members 31 of the spacer 3 shown in FIG. Since the design of the shape can be flexibly changed, the configuration of the battery module 1 can be flexibly changed.

  FIG. 2B is a plan view showing a state in which the rod-shaped member 31 is installed between the unit cells 2. As shown in FIG.2 (b), the axial direction cross section of the rod-shaped member 31 is a substantially square. Further, as shown in FIG. 2B, a space is formed by the adjacent unit cells 2 and the adjacent spacers 3, and this space becomes a flow path 32 for circulating the cooling medium. In this embodiment, air is used as the cooling medium. Since the rod-shaped members 31 are arranged in parallel at equal pitches between the unit batteries 2, the flow path 32 is uniformly formed in each part of the unit battery 2, and each part of the unit battery 2 can be cooled uniformly.

  Moreover, since the rod-shaped member 31 consists of a timepiece-shaped metal piece, it can be manufactured at low cost. Since the conventional heat sink is integrally formed, if there is a defect in a part of the heat sink, it is necessary to replace the entire heat sink, but in the case of this embodiment, only the defective bar member 31 can be replaced. It is enough to reduce the cost. Furthermore, since the bar-shaped member 31 has a simple shape (beat tree shape), the bar-shaped member 31 with high processing accuracy can be manufactured, and restrictions associated with the manufacturing of the bar-shaped member 31 such as size limitations can be reduced. In addition, since there is no base material for forming the hollow portion in the conventional spacer, the spacer 3 can be made thinner by the thickness, and the battery module can be downsized in the stacking direction as a whole. .

  The material of the comb-like jig 7 is preferably a flexible material that can be deformed to some extent so that it can be easily pulled out of the rod-shaped member 31 and can be easily rubbed so as to hold the rod-shaped member 31. The material of the comb-like jig 7 is preferably a material that can repeatedly hold and extract the rod-like member 31. As such a material, polypropylene, polyethylene, synthetic rubber, silicon rubber, or the like can be used.

  2C, the thickness dimension of the comb-shaped jig 7 in the stacking direction X is smaller than the thickness dimension of the rod-shaped member 31 in the same direction. Due to this configuration, even after the spacer is fixed, the comb-shaped jig 7 does not interfere with the unit battery 2 when the comb-shaped jig 7 is extracted from the rod-shaped member 31 and is easily extracted.

  By the way, as shown in FIG. 1, in this embodiment, the lamination direction cross section of the side plate 5 attached to the unit battery laminated body 11 which laminates | stacks the unit battery 2 and the spacer 3 is U-shaped (substantially rectangular shape). A shape in which one side of the frame is opened). In this case, when the comb-shaped jig 7 is extracted from the bar-shaped member 31, the lateral dimension of the comb-shaped jig 7 is preferably shorter than the lateral dimension of the unit battery 2 so as not to interfere with the side plate 5. . Furthermore, since the rod-shaped members 31 cannot be installed on both sides of the unit battery 2 as they are, the rod-shaped members 31 are manually installed on both sides of the unit battery 2. Or about the rod-shaped member 31 hold | maintained at the both ends of the comb-shaped jig | tool 7, the member which becomes a protrusion part toward the outer side in the center part of the rod-shaped member 31 is attached by a press, welding, an adhesive agent (broken line) ) May be used in advance, as shown in FIG. 3 (a). Thus, it can install in the form matched with the spacer 3 and the peripheral member by adjusting the shape of a comb-shaped jig | tool or a rod-shaped member flexibly.

・ Compression plate 4
As shown in FIG. 1, the compression plate 4 according to the present embodiment is made of a steel plate, has a circular opening 41 in the center, bolts 42 in the peripheral part, bolts toward both sides and the stacking direction X. A hole 43 is provided. The cross-sectional shape of the compression plate 4 is substantially the same as the cross-sectional shape of the unit battery 2. The compression plate 4 is installed at both ends of the unit cell stack 11 with a current collector plate, an insulating plate, and a compression support plate (not shown) interposed in this order. And the unit battery laminated body 11 is pressed with a big force from both ends via the compression plate 4, and the compression plate 4 and the side plate 5 of both ends are bolt-fixed. The unit battery 2 and the spacer 3 are compressed and fixed by this pressing.

・ Side plate 5
As shown in FIG. 1, the side plate 5 according to the present embodiment is a steel plate having a U-shaped cross section in the stacking direction of the unit battery 2, a through hole 51 for fixing the compression plate 4 to the bolt, and a reinforcing plate. 6 and through-holes 52 for fixing bolts, and are installed on both sides of the unit cell stack 11.

・ Reinforcement plate 6
As shown in FIG. 1, the reinforcing plate 6 according to the present embodiment is a steel plate having a U-shaped cross section in the stacking direction of the unit battery 2, a through hole 61 for fixing the side plate 5 to the bolt, and a battery module. 1 has a through hole (not shown) for attaching an eyebolt necessary for lifting. In addition, the reinforcing plate 6 is attached up and down after the side plate 5 is attached to the unit cell stack 11.

(Modification of spacer 3)
As shown in FIG. 3B, instead of the rod-shaped member 31 of the spacer 3 having the above structure, a spacer formed by a plate material having a corrugated cross section in the stacking direction of the unit cell may be used. In this way, since the area of the cross section in the stacking direction is increased, the electrical conductivity is also improved. Furthermore, since the surface area of the side surface in the figure of the corrugated plate material is larger than that of the rod-shaped member 31, the area in contact with air can be increased. Therefore, cooling of the spacer 3 is promoted and the cooling efficiency of the unit battery 2 can be improved.

(Modification of comb-shaped jig 7)
Moreover, as shown to Fig.4 (a), (b), the front-end | tip shape of each comb-tooth part 71 of the comb-tooth shaped jig | tool 7 can also be made into an acute angle, and can also be made into the rounded shape. In this way, when the rod-shaped member 31 is fitted in the comb-shaped jig 7 in advance along the longitudinal direction, the rod-shaped member 31 is guided between the comb-tooth portions 71, so that workability is good.

  Further, as shown in FIGS. 4C and 4D, the peripheral corners of the comb teeth 71 of the comb-shaped jig 7 can be chamfered. By doing so, the rod-shaped member 31 is guided between the comb-tooth portions 71 also when the rod-shaped member 31 is fitted in the comb-shaped jig 7 in the thickness direction in advance.

  In the present embodiment, the unit battery 2 and the spacer 3 are stacked in the lateral direction X. However, the present invention is not limited to this. For example, the unit battery 2 and the spacer 3 may be stacked in the vertical direction. In the case of stacking in the vertical direction, if the comb-like jig 7 shown in FIGS. 4C and 4D is used, the rod-shaped members 31 can be easily arranged.

[Cooling structure]
Next, the cooling structure according to the present embodiment will be described. As shown in FIG. 5, air flows from the bottom to the top through the flow path 32 surrounded by the rod-shaped member 31 and the unit battery 2 to cool the unit battery 2. At this time, air cools the rod-shaped member 31 and cools the unit cell 2 with which the cooled rod-shaped member 31 abuts from the surface. At the same time, the air directly contacts the unit cell 2 to bring the unit cell 2 to the surface. Cool from. Since the unit battery 2 has the configuration shown in FIG. 6, the heat generated in the positive electrode sheet 22 or the negative electrode sheet 24 of the unit battery 2 as a result of the battery reaction is transferred in the direction of the arrow shown in FIG. Since the current collector 21 and the negative electrode current collector 23 are exposed to air and released to the outside, the unit battery 2 can be efficiently cooled. By cooling the unit battery 2 in this way, the temperature of the unit battery 2 can be maintained in an appropriate range in which the battery reaction can be smoothly executed.

  Moreover, in the conventional battery module cooling structure such as Patent Document 1, air first cools the heat sink, and then the heat sink cools the unit battery. On the other hand, since the cooling structure of the present invention can directly cool the unit battery 2, the cooling efficiency can be further improved as compared with the conventional cooling structure.

(Modification 1 of cooling structure)
FIG. 7 shows an example of a structure for further improving the cooling efficiency in the present embodiment. FIG. 7 is a perspective view showing a configuration of a cooling unit 8 including an intake fan 81 for performing forced cooling and wind tunnels (air circulation spaces) 82 and 83. By disposing the battery module 1 shown in FIG. 1 inside the cooling unit 8, the air sucked into the lower air circulation space 82 by the intake fan 81 passes through the flow path 32 in the unit battery stack 11, It is discharged to the outside through the upper air circulation space 83. In FIG. 7, the arrow indicates the direction of air flow. Thus, by further providing a structure for forcibly cooling the battery module, the cooling efficiency can be further increased.

(Modification 2 of cooling structure)
As shown in FIG. 2A, in the present embodiment according to the present embodiment, the bar-shaped members 31 of the spacer 3 are installed in parallel at equal pitches, but the shape or arrangement of the bar-shaped members 31 is changed. A modification is shown below.

(A) FIG. 8A is a modification in which the central portion of the unit battery is wider than the end portion with respect to the pitch of the rod-shaped members 31. In this way, since the air flow rate at the central portion of the unit cell is larger than the air flow rate at the end portion, the central portion that is relatively hot can be actively cooled.

(B) FIG.8 (b) is the modification which made the shape of the rod-shaped member 31 the shape which swelled from the up-and-down both ends to the center part. In this way, the speed of the air passing through the flow path 32 is faster at the center of the unit cell than at the lower part of the unit cell. If it does so, the center part of the unit battery used as a comparatively high temperature can be actively cooled.

(C) FIG.8 (c) is the modification which cut off the center part of the rod-shaped member 31 other than that, with the rod-shaped member 31 of both ends as it is. In this way, the air that has passed through the end 32 and the center channel 32 of the unit cell is mixed in the center, so that the temperature of the air is uniformed and the air is uniformly distributed to the upper part of each channel 32. Can be shed.
As described above, according to the modified examples of FIGS. 8A to 8C, the heat accumulated in the unit cell can be efficiently released particularly when the unit cell is enlarged.

[Method for Manufacturing Battery Module 1]
Then, the manufacturing method of the battery module 1 which concerns on this embodiment is demonstrated using FIG. FIG. 9 is a diagram illustrating a manufacturing process of the battery module. In the present embodiment, the battery module 1 is intended for a case where four unit batteries 2 are stacked, but is not limited thereto.

・ Process I
As shown in FIGS. 9 (I) and (II), first, the unit battery 2 and the spacer 3 in a state where the rod-shaped member 31 is held in advance by the upper and lower comb-shaped jigs 7 are stacked to unitize the unit battery. The body 11 is molded. At this time, care should be taken to align the direction of each unit battery 2. The direction of each unit cell 2 refers to the direction of the positive electrode surface and the negative electrode surface, and the unit cells 2 are stacked so that the positive electrode surface and the negative electrode surface face each other. That is, the unit cells 2 are stacked with their orientations aligned so that all the unit cells 2 of the battery module 1 are connected in series via the conductive spacer 3.

・ Process II
Next, a compression plate 4 is arranged in the order of a current collector plate, an insulating plate, and a compression support plate (not shown) at both ends of the unit cell stack 11, and the unit cell stack is stacked from both ends via the compression plate 4. The body 11 is pressed.

・ Process III
And in the pressed state, the side plate 5 is attached to the both side surfaces of the unit cell stack 11 including the compression plate 4, and the compression plate 4 and the side plate 5 are bolted. Thereby, the unit battery 2 and the rod-shaped member 31 of the spacer 3 are compressed and fixed.

・ Process IV
Subsequently, as shown in FIG. 9 (III), the comb-shaped jig 7 holding the rod-shaped member 31 of each spacer 3 is extracted in the vertical direction.

・ Process V
Finally, as shown in FIG. 9 (IV), the reinforcing plate 6 is attached from above and below the unit cell stack 11, and the reinforcing plate 6 and the side plate 5 are bolted through the through-hole 61, and FIG. The unit battery module 1 shown in V) is completed.
Through the above steps, the rod-shaped member 31 as a spacer can be easily arranged in a manner that does not vary in installation method, and the battery module 1 can be manufactured.

(Modification of battery module manufacturing method)
The above is the manufacturing process of the unit cell module 1 in which the unit cell stack 11 is fixed by the compression plate 4, the U-shaped side plate 5 and the reinforcement plate 6. The compression plate 4, the side plate 5, and the reinforcement An example of the manufacturing process of the unit battery module 1 ′ that does not use the plate 6 will be described with reference to FIG. The unit battery module 1 ′ is such that the unit battery stack 11 ′ is compressed and fixed by the sandwiching plates 9 at both ends.

・ Process I
First, as shown in FIGS. 10 (I) and (II), a spacer 3 ′ and an end plate 4 ′ in which the rod-shaped member 31 ′ is held by the unit battery 2 ′ and the upper and lower comb-like jigs 7 ′. Are alternately stacked to form a unit cell assembly 11 ′.

・ Process II
Next, a sandwiching plate 9 is disposed in the order of a current collector plate, an insulating plate, and a compression support plate (not shown) at both ends of the unit battery stack 11 ′, and the unit is sandwiched from both ends via the sandwiching plate 9. The battery stack 11 ′ is pressed. The cross section in the stacking direction of the sandwiching plate 9 is larger in the lateral direction than the same cross section of the unit cell 2 ′, and two through holes 91 for fixing bolts are provided on both sides of the sandwiching plate 9. Yes.

・ Process III
Then, as shown in FIG. 10 (III), in the pressed state, four bolts longer than the dimension in the stacking direction of the unit cell stack 11 ′ are communicated with the through holes 91 of the sandwiching plates 9 at both ends. And fix with bolts. Thereby, each unit battery 2 ′ and the bar-shaped member 31 ′ of each spacer 3 ′ are compressed and fixed.

・ Process IV
Subsequently, as shown in FIG. 10 (IV), the upper and lower comb-shaped jigs 7 ′ holding the rod-shaped members 31 ′ of the spacers 3 ′ are extracted. At this time, a reinforcing plate (not shown) may be disposed below the unit cell stack 11 ′, and the reinforcing plate and the sandwiching plates 9 at both ends may be fixed.

・ Process V
Thereby, the battery module 1 ′ shown in FIG. 10 (V) is completed.
Thus, even when manufacturing battery module 1 'using a volt | bolt, this can be easily arrange | positioned in the form without dispersion | variation by incorporating a rod-shaped member into spacer 3' as a manufacturing process.

  As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but various additions, modifications, or deletions can be made without departing from the spirit of the present invention. In particular, in the present embodiment, the rod-shaped members 31 extending in the height direction of the unit battery 2 are arranged at an equal pitch in the lateral direction of the unit battery 2, but instead of this, the lateral direction of the unit battery 2 is arranged. It is also possible to arrange the rod-shaped members extending in the same direction in the height direction of the unit battery 2 at an equal pitch. Further, the stacking direction of the unit cells 2 may be the vertical direction instead of the horizontal direction X. Therefore, such a thing is also included in the scope of the present invention.

  The battery module according to the present invention can be suitably used for hybrid vehicles, railway vehicles, generators, and the like.

1, 1 'battery module 11 unit cell stack 2, 2' unit battery 21 positive electrode current collector 22 positive electrode sheet 23 negative electrode current collector 24 negative electrode sheet 25 separator 3, 3 'spacer 31, 31' rod-shaped member 32 channel ( Cooling medium flow path)
4 compression plate 4 'end plate 41 opening 42 bolt hole 43 bolt hole 5 side plate 51 through hole 52 through hole 6 reinforcing plate 61 through hole 7, 7' comb tooth jig 71 comb tooth portion 8 cooling unit 81 intake fan 82 Upper air circulation space 83 Lower air circulation space 9 Clamping plate 91 Through hole

Claims (20)

In a battery module in which a plurality of unit cells are stacked and spacers are arranged between adjacent unit cells,
The spacer is composed of a plurality of rod-shaped members extending in a predetermined direction,
The rod-shaped member is sandwiched between the two unit batteries that contact the front and rear in the stacking direction,
A battery module characterized in that a space between adjacent rod-shaped members is formed as a cooling medium flow path. The unit cell has either a positive electrode or a negative electrode on the front surface in the stacking direction, and the other electrode on the rear surface,
The battery module according to claim 1, wherein the rod-shaped member is conductive. The spacer is held by a comb-like jig to which each rod-like member can be attached and detached before being fixed between the unit cells.
The battery module according to claim 1 or 2, wherein the comb-shaped jig is removed after fixing between the unit batteries.   The battery module according to any one of claims 1 to 3, wherein an axial cross section of the rod-shaped member has a rectangular shape.   The battery module according to claim 4, wherein the rectangular shape is a square or a rectangle whose side parallel to the stacking direction is shorter than the other side.   5. The battery module according to claim 1, wherein at least a part of the rod-shaped member is formed of a plate material having a corrugated cross section in the stacking direction.   The battery module according to claim 1, wherein the rod-shaped members are arranged in parallel at equal pitches between the unit batteries.   The battery module according to any one of claims 1 to 7, wherein the rod-like member is arranged at a central portion wider than a pitch at which both end portions of the unit batteries are arranged. .   9. The battery module according to claim 1, wherein the cross-section in the stacking direction of the rod-shaped member has a shape that swells from both ends to the center.   The battery module according to claim 1, wherein the unit battery is a nickel metal hydride battery. A method for manufacturing a battery module in which a plurality of unit cells are stacked,
A step of stacking the unit battery and a spacer made of a plurality of rod-like members fitted in advance in a comb-like jig to form a unit battery assembly;
Pressing the unit cell assembly in the stacking direction;
And a step of removing the comb-shaped jig from the rod-shaped member after pressing the unit battery assembly. A method for manufacturing a battery module in which a plurality of unit cells are stacked,
A step of stacking the unit battery and a spacer made of a plurality of rod-like members fitted in advance in a comb-like jig to form a unit battery assembly;
Disposing sandwiching plates for sandwiching the unit cell assembly from both sides at both ends in the stacking direction of the unit cell assembly; and
A cross section in the stacking direction of the sandwich plate is larger in the lateral direction than the same cross section of the unit cell, and through holes for inserting bolts are provided on both sides of the sandwich plate. Pressing the unit cell assembly in the stacking direction via
After pressing the unit cell assembly, the bolts are communicated between the clamping plates, and the clamping plates at both ends are fastened by the bolts so that the unit cell assembly is clamped from both ends in the stacking direction. And a process of
And a step of removing the comb-shaped jig from the rod-shaped member after the bolt and the clamping plate are fastened.   The method for manufacturing a battery module according to claim 11, wherein the comb-shaped jig is flexible.   The method of manufacturing a battery module according to any one of claims 11 to 13, wherein a tip of a comb tooth portion of the comb-like jig is formed with an acute angle or a rounded shape.   The method of manufacturing a battery module according to any one of claims 11 to 14, wherein a peripheral corner portion of a comb tooth portion of the comb-like jig is chamfered. A battery module formed by laminating a plurality of unit cells between adjacent unit cells and forming a cooling medium flow path for cooling the unit cells,
Consisting of a plurality of rod-shaped members extending in a predetermined direction,
The rod-shaped member is sandwiched between the two unit batteries that contact the front and rear in the stacking direction,
A battery spacer characterized in that a space between adjacent rod-shaped members is used as the cooling medium flow path.   The battery spacer according to claim 16, wherein the rod-shaped member is conductive. The spacer is held by a comb-like jig to which the rod-shaped member can be attached and detached before being fixed between the unit cells.
The battery spacer according to claim 16 or 17, wherein the jig is removed after fixing to the unit battery.   The battery spacer according to any one of claims 16 to 18, wherein the rod-like members are arranged in parallel at equal pitches between the unit batteries.   The battery spacer according to claim 18 or 19, wherein the comb-shaped jig is flexible.