JP2019179671A - Power storage module - Google Patents

Abstract

To provide a power storage module which enables improvement of reliability.SOLUTION: A power storage module 12 includes: a frame body 50 provided with openings 50a communicating with multiple internal spaces V between bipolar electrodes 32; pressure regulator valves 60 connected with the openings 50a; and an electrolytic solution housed in the internal spaces V. Each pressure regulator valve 60 has a case 80, a valve body 90, and a cover 100. The case 80 is formed with multiple storage spaces 89P which communicate with the internal spaces V through the openings 50a and house the respective valve bodies 90. The cover 100 is provided with exhaust ports 100a for discharging a gas that flows from at least one of the multiple internal spaces V into the storage spaces 89P to the outside. An adsorption member 110A used for adsorbing the electrolytic solution and made of unwoven fabric is disposed on an outer surface of the cover 100.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a power storage module.

  There is known a bipolar battery (storage module) including a bipolar electrode in which a positive electrode is formed on one surface of a current collector and a negative electrode is formed on the other surface (see Patent Document 1). In this battery, an electrolytic solution is sealed in an internal space defined by a separator, a current collector, and a seal member. Bipolar electrodes are laminated via an electrolyte layer made of a separator impregnated with an electrolytic solution. The battery is provided with a tube that penetrates the seal portion. One end of the tube faces the internal space, and the other end faces the external space of the battery. When the internal space pressure increases while using the battery, this tube functions as a pressure regulating valve.

JP 2010-287451 A

  However, in the configuration described in Patent Document 1, when the gas in the internal space is discharged to the external space through the tube, the electrolyte may be discharged into the external space and diffused together with the gas. If the electrolytic solution is diffused outside, there is a possibility that, for example, corrosion or short-circuiting of adjacent conductive plates may occur, which is not preferable from the viewpoint of reliability.

  An object of this invention is to provide the electrical storage module which can improve reliability.

  An electricity storage module according to the present invention includes a laminated body including an electrode plate, a positive electrode provided on one surface of the electrode plate, and a negative electrode provided on the other surface of the electrode plate, and having a plurality of laminated bipolar electrodes. A frame body that holds an edge of the electrode plate and has an opening communicating with a plurality of internal spaces between adjacent bipolar electrodes in the laminate, a pressure regulating valve connected to the opening, and an internal space The pressure regulating valve is provided in the case so as to close the case, a case connected to the internal space through the opening, a plurality of valve bodies accommodated in the case, and the pressure regulating valve. A cover, and the case is formed with a plurality of storage spaces that communicate with each of the internal spaces through the opening and store each of the valve bodies, and the cover includes the plurality of internal spaces. From at least one of And an exhaust port is provided for discharging the gas flowing into the space to the outside, the outer surface of the cover, the suction member comprising a nonwoven fabric for adsorbing an electrolyte is disposed.

  In this power storage module, a pressure regulating valve is connected to an opening communicating with the internal space in which the electrolytic solution is accommodated. The case connected to the internal space in the pressure regulating valve is formed with a plurality of storage spaces that are connected to the internal spaces and store the valve bodies. The case is closed by a cover. The cover is provided with an exhaust port for discharging gas flowing into the accommodation space from at least one of the plurality of internal spaces to the outside. Moreover, the adsorption | suction member which consists of a nonwoven fabric for adsorb | sucking electrolyte solution is arrange | positioned at the outer surface of the cover. Therefore, if the internal pressure in the internal space rises, gas is discharged from the exhaust port of the cover through the housing space, and the pressure in the internal space is adjusted. At this time, there is a possibility that the electrolyte together with the gas may be discharged from the exhaust port through the accommodation space, but this electrolyte is adsorbed and held by the adsorption member on the outer surface of the cover. Therefore, it is suppressed that the electrolyte solution discharged to the outside together with the gas from the exhaust port of the cover is diffused outside. Therefore, reliability is improved.

  In the power storage module according to the present invention, a surplus space around the accommodation space is formed in the case, and an adsorption member may be disposed in the surplus space. In this case, the electrolytic solution that goes to the exhaust port together with the gas through the accommodation space is adsorbed and held by the adsorption member disposed in the surplus space around the accommodation space. Accordingly, the electrolyte is prevented from being discharged together with the gas from the exhaust port of the cover. Therefore, reliability is reliably improved.

  In the power storage module according to the present invention, the adsorption amount of the electrolytic solution in the adsorption member may be equal to or greater than the volume of the electrolytic solution accommodated in one internal space. In this case, even if all of the electrolytic solution accommodated in one internal space leaks out from the internal space, it is possible to suppress the loss of reliability.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical storage module which can improve reliability can be provided.

It is a schematic sectional drawing which shows one Embodiment of an electrical storage apparatus provided with an electrical storage module. It is a schematic sectional drawing which shows the electrical storage module which comprises the electrical storage apparatus of FIG. It is a perspective view which shows the electrical storage module of FIG. It is a disassembled perspective view of the pressure regulation valve connected to opening of a frame. It is the schematic which shows each opening of a frame. It is a schematic sectional drawing which shows the structure of a pressure regulating valve. It is a figure which shows the side surface by the side of (A) frame opening of a base, and the (B) case side. It is a disassembled perspective view which shows the side by the side of the base of a case. It is a figure which shows the (A) base side surface and (B) cover side surface of a case. It is a schematic sectional drawing which shows the structure of a part of pressure regulating valve. It is a figure which shows the side surface by the side of the cover of a pressure regulating valve. It is a figure which shows the side surface by the side of the cover of the pressure regulation valve which concerns on a modification.

  Hereinafter, an embodiment of a power storage module will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description may be omitted. In the drawing, an XYZ orthogonal coordinate system is shown.

  FIG. 1 is a schematic cross-sectional view illustrating an embodiment of a power storage device including a power storage module. The power storage device 10 shown in the figure is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 10 includes a plurality (three in the present embodiment) of power storage modules 12, but may include a single power storage module 12. The power storage module 12 is, for example, a bipolar battery. The power storage module 12 is a secondary battery such as a nickel hydride secondary battery or a lithium ion secondary battery, but may be an electric double layer capacitor. In the following description, a nickel metal hydride secondary battery is illustrated.

  The plurality of power storage modules 12 can be stacked via a conductive plate 14 such as a metal plate. As viewed from the stacking direction D1, the power storage module 12 and the conductive plate 14 have, for example, a rectangular shape. Details of each power storage module 12 will be described later. The conductive plates 14 are also arranged outside the power storage modules 12 positioned at both ends in the stacking direction D1 (Z direction) of the power storage modules 12, respectively. The conductive plate 14 is electrically connected to the adjacent power storage module 12. Thereby, the some electrical storage module 12 is connected in series in the lamination direction D1. In the stacking direction D1, a positive electrode terminal 24 is connected to the conductive plate 14 located at one end, and a negative electrode terminal 26 is connected to the conductive plate 14 located at the other end. The positive terminal 24 may be integrated with the conductive plate 14 to be connected. The negative electrode terminal 26 may be integrated with the conductive plate 14 to be connected. The positive electrode terminal 24 and the negative electrode terminal 26 extend in a direction (X direction) intersecting the stacking direction D1. The positive and negative terminals 24 and 26 can charge and discharge the power storage device 10.

  The conductive plate 14 can also function as a heat radiating plate for releasing heat generated in the power storage module 12. When a refrigerant such as air passes through the plurality of gaps 14a provided inside the conductive plate 14, heat from the power storage module 12 can be efficiently released to the outside. Each gap 14a extends, for example, in a direction (Y direction) intersecting the stacking direction D1. As viewed from the stacking direction D1, the conductive plate 14 is smaller than the power storage module 12, but may be the same as or larger than the power storage module 12.

  The power storage device 10 may include a restraining member 16 that restrains the alternately stacked power storage modules 12 and conductive plates 14 in the stacking direction D1. The restraining member 16 includes a pair of restraining plates 16A and 16B and a connecting member (bolt 18 and nut 20) for joining the restraining plates 16A and 16B to each other. An insulating film 22 such as a resin film is disposed between the restraining plates 16A and 16B and the conductive plate. Each restraint plate 16A, 16B is comprised, for example with metals, such as iron. When viewed from the stacking direction D1, the restraining plates 16A and 16B and the insulating film 22 have, for example, a rectangular shape. The insulating film 22 is larger than the conductive plate 14, and the restraining plates 16 </ b> A and 16 </ b> B are larger than the power storage module 12. As viewed from the stacking direction D1, an insertion hole H1 through which the shaft portion of the bolt 18 is inserted is provided at a position on the outer side of the power storage module 12 at the edge portion of the restraint plate 16A. Similarly, an insertion hole H2 through which the shaft portion of the bolt 18 is inserted is provided at a position on the outer side of the power storage module 12 at the edge portion of the restraining plate 16B when viewed from the stacking direction D1. When each restraint plate 16A, 16B has a rectangular shape when viewed from the stacking direction D1, the insertion hole H1 and the insertion hole H2 are located at the corners of the restraint plates 16A, 16B.

  One constraining plate 16A is abutted against the conductive plate 14 connected to the negative terminal 26 via the insulating film 22, and the other constraining plate 16B has the insulating film 22 applied to the conductive plate 14 connected to the positive terminal 24. Has been hit through. For example, the bolt 18 is passed through the insertion hole H1 from one restraint plate 16A side to the other restraint plate 16B side, and a nut 20 is screwed onto the tip of the bolt 18 protruding from the other restraint plate 16B. Yes. Thereby, the insulating film 22, the conductive plate 14, and the power storage module 12 are sandwiched and unitized, and a restraining load is applied in the stacking direction D1.

  2 is a schematic cross-sectional view showing a power storage module constituting the power storage device of FIG. The power storage module 12 shown in the figure includes a stacked body 30 including a plurality of stacked bipolar electrodes (electrodes) 32. The laminated body 30 has, for example, a rectangular shape when viewed from the lamination direction D1 of the bipolar electrode 32. A separator 40 may be disposed between the adjacent bipolar electrodes 32. The bipolar electrode 32 includes an electrode plate 34, a positive electrode 36 provided on one surface of the electrode plate 34, and a negative electrode 38 provided on the other surface of the electrode plate 34. In the stacked body 30, the positive electrode 36 of one bipolar electrode 32 faces the negative electrode 38 of one bipolar electrode 32 adjacent in the stacking direction D 1 across the separator 40, and the negative electrode 38 of one bipolar electrode 32 is connected to the separator 40. Is opposed to the positive electrode 36 of the other bipolar electrode 32 adjacent in the stacking direction D1. In the stacking direction D1, an electrode plate 34 (negative electrode termination electrode) having a negative electrode 38 disposed on the inner surface is disposed at one end of the stacked body 30, and a positive electrode 36 is disposed on the inner surface at the other end of the stacked body 30. The disposed electrode plate 34 (positive terminal electrode) is disposed. The negative electrode 38 of the negative electrode-side termination electrode faces the positive electrode 36 of the uppermost bipolar electrode 32 with the separator 40 interposed therebetween. The positive electrode 36 of the positive terminal electrode is opposed to the negative electrode 38 of the lowermost bipolar electrode 32 with the separator 40 interposed therebetween. The electrode plates 34 of these termination electrodes are connected to the adjacent conductive plates 14 (see FIG. 1).

  The power storage module 12 includes a frame 50 that holds the edge 34a of the electrode plate 34 on the side surface 30a of the stacked body 30 extending in the stacking direction D1. The frame body 50 is provided around the stacked body 30 when viewed from the stacking direction D1. That is, the frame body 50 is configured to surround the side surface 30 a of the stacked body 30. The frame 50 can include a first resin portion 52 that holds the edge portion 34a of the electrode plate 34, and a second resin portion 54 that is provided around the first resin portion 52 when viewed from the stacking direction D1.

  The first resin portion 52 constituting the inner wall of the frame 50 is provided from one surface (surface on which the positive electrode 36 is formed) of the electrode plate 34 of each bipolar electrode 32 to the end surface of the electrode plate 34 at the edge portion 34a. . As viewed from the stacking direction D1, each first resin portion 52 is provided over the entire circumference of the edge portion 34a of the electrode plate 34 of each bipolar electrode 32. Adjacent first resin portions 52 are in contact with each other on the surface extending outside the other surface (surface on which the negative electrode 38 is formed) of the electrode plate 34 of each bipolar electrode 32. As a result, the edge portion 34 a of the electrode plate 34 of each bipolar electrode 32 is buried and held in the first resin portion 52. Similarly to the edge portion 34 a of the electrode plate 34 of each bipolar electrode 32, the edge portions 34 a of the electrode plates 34 disposed at both ends of the laminated body 30 are also held in a state of being buried in the first resin portion 52. Thus, an internal space V that is airtightly partitioned by the electrode plates 34 and 34 and the first resin portion 52 is formed between the electrode plates 34 and 34 adjacent in the stacking direction D1. In the internal space V, for example, an electrolytic solution (not shown) made of an alkaline solution such as an aqueous potassium hydroxide solution is accommodated.

  The 2nd resin part 54 which comprises the outer wall of the frame 50 is a cylindrical part extended about the lamination direction D1 as an axial direction. The second resin portion 54 extends over the entire length of the stacked body 30 in the stacking direction D1. The second resin portion 54 covers the outer surface of the first resin portion 52 extending in the stacking direction D1. The second resin portion 54 is welded to the first resin portion 52 on the inner side when viewed from the stacking direction D1.

  The electrode plate 34 is made of a metal such as nickel or a nickel-plated steel plate, for example. As an example, the electrode plate 34 is a rectangular metal foil made of nickel. The edge portion 34 a of the electrode plate 34 is an uncoated region where the positive electrode active material and the negative electrode active material are not coated, and the uncoated region is buried in the first resin portion 52 constituting the inner wall of the frame body 50. It is an area to be held. An example of the positive electrode active material constituting the positive electrode 36 is nickel hydroxide. Examples of the negative electrode active material constituting the negative electrode 38 include a hydrogen storage alloy. The formation region of the negative electrode 38 on the other surface of the electrode plate 34 is slightly larger than the formation region of the positive electrode 36 on one surface of the electrode plate 34.

  The separator 40 is formed in a sheet shape, for example. Examples of the material forming the separator 40 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), and a woven fabric or a nonwoven fabric made of polypropylene. The separator 40 may be reinforced with a vinylidene fluoride resin compound or the like. The separator 40 is not limited to a sheet shape, and may be a bag shape.

  The frame 50 (the first resin portion 52 and the second resin portion 54) is formed in a rectangular cylindrical shape by, for example, injection molding using an insulating resin. Examples of the resin material constituting the frame 50 include polypropylene (PP), polyphenylene sulfide (PPS), and modified polyphenylene ether (modified PPE).

  FIG. 3 is a schematic perspective view showing the power storage module 12 of FIG. FIG. 4 is an exploded perspective view of the pressure regulating valve 60 connected to the opening 50 a of the frame body 50. As shown in FIGS. 3 and 4, the frame 50 of the power storage module 12 has a side surface 50 s extending in the stacking direction D <b> 1. The side surface 50s is a surface located outside as viewed from the stacking direction D1. Therefore, the second resin portion 54 has the side surface 50 s of the frame body 50.

  There are a plurality (four here) of one side surface 50s (here, one side surface 50s facing the longitudinal direction (X direction) of the frame body 50) forming one side of the frame body 50 when viewed from the stacking direction D1. Openings 50a (openings 50a1 to 50a4) are provided. Each opening 50a functions as a liquid injection port for injecting the electrolyte into each internal space V, and also functions as a connection port for the pressure regulating valve 60 after the electrolyte is injected.

  As shown in FIG. 4, one opening 50 a includes a first opening 52 a provided in the first resin portion 52 and a second opening 54 a provided in the second resin portion 54. Each first opening 52 a communicates with the internal space V between adjacent bipolar electrodes 32. The first resin part 52 is provided with a plurality (six in this case) of first openings 52a, and the second resin part 54 is a single second opening that extends so as to cover the plurality of first openings 52a. 54a is provided. The first opening 52 a may be provided in each first resin portion 52, or may be provided between adjacent first resin portions 52. Each of the first openings 52a and the second openings 54a has a rectangular shape, for example. In the present embodiment, a notch 54b for the base 70 of the pressure regulating valve 60 to enter is formed above the second opening 54a.

  FIG. 5 is a view showing the openings 50a1 to 50a4 (viewed from the X direction). In FIG. 5, illustration of the second resin portion 54 around the first resin portion 52 is omitted. In the present embodiment, 24 internal spaces V are formed in the power storage module 12, and one opening 50a communicates with 6 internal spaces V whose height positions in the stacking direction D1 are shifted by 4 steps. ing. Each internal space V communicates with any one of the four openings 50a1 to 50a4. As shown in FIG. 5, six first openings 52 a are arranged in two rows in the short direction (Y direction) of the frame body 50 in one opening 50 a. In each row, three first openings 52a are arranged along the stacking direction D1 (Z direction).

  For example, the arrangement of the first openings 52a in each opening 50a can be configured to shift the set of the internal spaces V that are in communication one step at a time. In the following description, for the sake of convenience, in order to identify the 24 internal spaces V, the internal space V1 is arranged in the order from the other end (the lower side in FIG. 2) to the one end (the upper side in FIG. 2) of the stacked body 30. This is expressed as ~ V24.

  As shown in FIG. 5A, the first openings 52a4, 52a12, and 52a20 communicated with the internal spaces V4, V12, and V20 are formed in the first row of openings 50a1 (the column on the left side in the drawing, the same applies hereinafter). Is provided. First openings 52a8, 52a16, and 52a24 communicating with the internal spaces V8, V16, and V24 are provided in the second row of the openings 50a1 (the right-hand column in the drawing; the same applies hereinafter).

  As shown in FIG. 5B, the first row of openings 50a2 is provided with first openings 52a3, 52a11, 52a19 communicating with the internal spaces V3, V11, V19. In the second row of the openings 50a2, first openings 52a7, 52a15, 52a23 communicating with the internal spaces V7, V15, V23 are provided.

  As shown in FIG. 5C, the first row of openings 50a3 is provided with first openings 52a2, 52a10, 52a18 communicating with the internal spaces V2, V10, V18. In the second row of openings 50a3, first openings 52a6, 52a14, 52a22 communicating with the internal spaces V6, V14, V22 are provided.

  As shown in FIG. 5D, the first row of openings 50a4 is provided with first openings 52a1, 52a9, 52a17 communicating with the internal spaces V1, V9, V17. In the second row of the openings 50a4, first openings 52a5, 52a13, 52a21 communicating with the internal spaces V5, V13, V21 are provided.

  According to the arrangement of the first openings 52a as described above (that is, the correspondence between the first openings 52a1 to 52a24 and the internal spaces V1 to V24), all the internal spaces V communicate with the first openings 52a different from each other. Is realized.

  Subsequently, the configuration of the pressure regulating valve 60 connected to the opening 50a of the frame 50 will be described with reference to FIGS. 4 and 6 to 11. FIG. 6 is a schematic cross-sectional view showing the configuration of the pressure regulating valve 60. FIG. 6 is a cross-sectional view including a cross section of a communication path (communication path formed by the first opening 52a12, the first communication hole 74, and the second communication hole 84) corresponding to the internal space V12. As shown in FIGS. 4 and 6, the pressure regulating valve 60 includes a base 70, a case 80, a plurality of (here, six) valve bodies 90, and a cover 100.

  The base 70 has a substantially rectangular parallelepiped outer shape, and is formed of, for example, polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), or the like. The base 70 is connected to the opening 50a. When viewed from the X direction, the lower surface and both side surfaces of the base 70 are positioned by the second opening 54a. The base 70 is fixed to the opening 50a by, for example, welding part or all of the contact portion between the side surface 71 and the first resin portion 52. The side surface 71 and the first resin portion 52 are welded by, for example, hot plate welding, laser transmission welding, ultrasonic welding, or the like.

  FIG. 7A is a plan view showing the side surface 71, and FIG. 7B is a plan view showing the side surface 72 (first side surface) of the base 70. The side surface 72 is a side surface opposite to the opening 50 a and faces the case 80. As shown in FIGS. 6 and 7, the base 70 is provided with a plurality of (here, six) first communication holes 73 to 78 that penetrate from the side surface 71 to the side surface 72. The first communication holes 73 to 78 are communication holes that communicate with the first openings 52a4, 52a12, 52a20, 52a24, 52a16, and 52a8. The configuration of the first communication holes 76 to 78 is the same as the configuration of the first communication holes 73 to 75. Specifically, the first communication holes 76 to 78 are configured symmetrically with the first communication holes 73 to 75 with respect to the axis A that passes through the centers of the side surfaces 71 and 72 and is orthogonal to the side surfaces 71 and 72. . Therefore, in the following, the first communication holes 73 to 75 will be described, and the description of the first communication holes 76 to 78 will be omitted.

  The first communication hole 74 located in the middle stage is formed in a rectangular parallelepiped shape extending along the X direction.

  The first communication hole 73 located in the lower stage has a rectangular parallelepiped communication portion 73b extending along the X direction and a tapered shape in which the vertical width (width in the Z direction) increases toward the case 80 along the X direction. And a tapered portion 73c formed. The taper part 73c is provided so that the space | interval between the 1st communicating holes 73 and 74 becomes small as it goes to the case 80 along the X direction. The communication part 73b forms a section from the opening end 73a on the opening 50a side of the first communication hole 73 to a midway position of the first communication hole 73, and the taper part 73c extends from the midway position to the first communication hole 73. The section to the opening end 73d on the case 80 side is formed. The tapered portion 73c plays a role of position adjustment for communicating the first communication hole 73 and the second communication hole 83 provided in the case 80.

  The first communication hole 75 located in the upper stage has a rectangular parallelepiped communication portion 75b extending along the X direction and a tapered shape in which the vertical width (width in the Z direction) increases toward the case 80 along the X direction. And a tapered portion 75c formed. The taper part 75c is provided so that the space | interval between the 1st communicating holes 74 and 75 becomes small as it goes to the case 80 along the X direction. The communication part 75b forms a section from the opening end 75a on the opening 50a side of the first communication hole 75 to a midway position of the first communication hole 75, and the taper part 75c extends from the midway position to the first communication hole 75. The section to the opening end 75d on the case 80 side is formed. The tapered portion 75c plays a role of position adjustment for communicating the first communication hole 75 with the second communication hole 85 provided in the case 80.

  The opening ends 73a to 75a of the first communication holes 73 to 75 are formed in a size including the first openings 52a4, 52a12, and 52a20 when viewed from the X direction. The vertical widths d1 of the open ends 73a to 75a are all the same.

  The arrangement of the six first openings 52a in the openings 50a1 to 50a4 is shifted by one step as described above. For this reason, in order to use the pressure regulation valve 60 of the same standard (common shape) for all the openings 50a1 to 50a4, even when the base 70 of the pressure regulation valve 60 is connected to any of the openings 50a1 to 50a4, The first communication holes 73 to 78 need to communicate with the corresponding first openings 52a. For example, the first communication hole 73 of the base 70 communicates with the first opening 52a4. However, when the base 70 is connected to the opening 50a2, it is necessary to communicate with the first opening 52a3. When the base 70 is connected to the opening 50a3, it is necessary to communicate with the first opening 52a2. When the base 70 is connected to the opening 50a4, it is necessary to communicate with the first opening 52a1.

  Therefore, in the present embodiment, the vertical width d1 of the opening ends 73a to 75a is the product of the width of one structure repeated in the stacked body 30 (that is, the above-described shift width of one step) and the number of openings 50a. It is set to the value or higher. In the present embodiment, the width of one structure repeated in the stacked body 30 is the width d2 (see FIG. 2) in the stacking direction D1 of the portion where one electrode plate 34 and one internal space V are combined. That is, in the present embodiment, the relationship “d1 ≧ d2 × 4” is established. Thereby, even when the base 70 is connected to any of the openings 50a1 to 50a4, the corresponding first openings 52a are accommodated inside the opening ends 73a to 75a when viewed from the X direction. As a result, the same base 70 (that is, the same pressure regulating valve 60) can be used for any of the openings 50a1 to 50a4. Thereby, the kind of member required can be reduced. Further, since it is not necessary to use a pressure regulating valve 60 with a different standard for each opening 50a, it is possible to prevent the occurrence of erroneous assembly such as connecting a pressure regulating valve 60 with a standard that does not conform to the opening 50a. .

  Further, as shown in FIG. 7A, the plurality of opening ends 73 a to 78 a are arranged point-symmetrically with respect to an axis A that passes through the center of the side surface 71 and is orthogonal to the side surface 71. According to this configuration, the positional relationship of the plurality of opening ends with respect to the opening 50a is the same in any of the two states (postures) of the base 70 that are in an inverted relationship with respect to the axis A. For this reason, the base 70 can be normally connected to the opening 50a in any of the above two states. Specifically, the base 70 can be connected to the opening 50a1 even if the base 70 is reversed (rotated 180 degrees) from the state shown in FIG. For example, the first communication hole 73 communicating with the first opening 52a4 communicates with the first opening 52a24 in the inverted state. As a result, the base 70 can be easily connected to the opening 50a. Further, it is possible to prevent erroneous assembly such that the base 70 is connected to the opening 50a in an incorrect direction.

  As shown in FIG. 7B, each of the plurality of first communication holes 73 to 78 is formed on the side surface 72 of the base 70 when viewed from the connection direction D2 (that is, the X direction) between the base 70 and the case 80. First joining protrusions 72A and 72B extending along the connection direction D2 so as to partition are provided.

  The first bonding protrusion 72A includes four wall portions 72A1 erected on the edge portions extending along the Y direction of the rectangular opening ends 73d to 75d, and the Z direction of the opening ends 73d to 75d. And two wall portions 72 </ b> A <b> 2 erected on the edge extending along the same. Similarly, the first bonding projection 72B includes four wall portions 72B1 erected on the edges extending along the Y direction of the rectangular opening ends 76d to 78d, and the opening ends 76d to 78d. And two wall portions 72B2 erected on the edge extending along the Z direction.

  In addition, columnar first measurement protrusions 72 </ b> C extending in the connection direction D <b> 2 are provided at the four corners of the side surface 72. The first measurement projection 72C is provided so as not to interfere with second joining projections 81A and 81B and the second measurement projection 81C of the case 80 described later. That is, the first measurement protrusion 72C is provided at a position that does not overlap with the second bonding protrusions 81A and 81B and the second measurement protrusion 81C when viewed from the connection direction D2.

  The case 80 is connected to the internal space V through the opening 50 a of the frame body 50 and the first communication holes 73 to 78 of the base 70. The case 80 is a box-shaped member having a substantially rectangular parallelepiped outer shape, and is formed of, for example, polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE). The case 80 is joined to the side surface 72 of the base 70 at a side surface 81 (second side surface) corresponding to the bottom surface of the box. FIG. 8 is an exploded perspective view showing the side surface 81 of the case 80. 9A is a plan view showing the side surface 81, and FIG. 9B is a plan view of the case 80 viewed from the cover 100 side.

  As shown in FIGS. 8 and 9, the case 80 has a plurality (six in this case) of second communication holes 83 to 83 that penetrate from the side surface 81 to the inner side surface 82 (the inner side surface of the side plate forming the side surface 81). 88 is provided. The second communication holes 83 to 88 are formed in a columnar shape. Each of the second communication holes 83 to 88 communicates with one internal space V via the corresponding first communication holes 73 to 78.

  As shown in FIG. 8 and FIG. 9A, the connection direction is formed on the side surface 81 of the case 80 so as to partition each of the plurality of second communication holes 83 to 88 when viewed from the connection direction D <b> 2 (X direction). Second joining protrusions 81A and 81B extending along D2 are provided.

  The second joining projections 81A and 81B have shapes corresponding to the first joining projections 72A and 72B, and are provided so as to overlap the first joining projections 72A and 72B when viewed from the connection direction D2. It has been. In other words, the second bonding projection 81A has four wall portions 81A1 corresponding to the four wall portions 72A1 and two wall portions 81A2 corresponding to the two wall portions 72A2. Similarly, the second bonding projection 81B has four wall portions 81B1 corresponding to the four wall portions 72B1 and two wall portions 81B2 corresponding to the two wall portions 72B2.

  In addition, columnar second measurement protrusions 81C extending in the connection direction D2 are provided at the four corners of the side surface 81. The second measurement protrusion 81C is provided so as not to interfere with the first bonding protrusions 72A and 72B and the first measurement protrusion 72C. That is, the second measurement protrusion 81C is provided at a position that does not overlap with the first bonding protrusions 72A and 72B and the first measurement protrusion 72C when viewed from the connection direction D2.

  The base 70 and the case 80 are joined to each other by hot plate welding the ends of the first joining projections 72A and 72B and the ends of the second joining projections 81A and 81B. Accordingly, the side surface 72 of the base 70 and the side surface 81 of the case 80 are formed by a plurality of communication holes formed by the plurality of first communication holes 73 to 78 and the plurality of second communication holes 83 to 88 when viewed from the connection direction D2. It connects via the partition wall W extended along the connection direction D2 so that each of a channel | path may be partitioned off. The partition wall W is a wall portion formed so as to connect the side surface 72 and the side surface 81 by hot plate welding of the first bonding projections 72A and 72B and the second bonding projections 81A and 81B. It is.

  In the hot plate welding, the hot plate is pressed so as to be parallel to the ends of the first joining projections 72A and 72B. At this time, the end of the first measurement projection 72C is similarly pressed against the end of the first measurement projection 72C, so that the end of the first measurement projection 72C is solidified after being melted by the hot plate welding. It has become. Similarly, in the hot plate welding, the hot plate is pressed so as to be parallel to the end portions of the second bonding projections 81A and 81B. At this time, the end of the second measurement projection 81C is similarly pressed against the end of the second measurement projection 81C, so that the end of the second measurement projection 81C is solidified after being melted by the hot plate welding. It has become.

  As shown in FIG. 7B and FIG. 9A, a plurality of opening ends 73 d to 78 d provided on the side surface 72 of the base 70 and a plurality of opening ends provided on the side surface 81 of the case 80. All of 83a to 88a (first opening ends) are arranged point-symmetrically with respect to the axis A. Further, the first joining protrusions 72A and 72B and the second joining protrusions 81A and 81B are also arranged point-symmetrically with respect to the axis A. On the other hand, the first measurement protrusion 72C and the second measurement protrusion 81C are arranged so as not to be point-symmetric with respect to the axis A. As shown in FIG. 7B, in the present embodiment, the first measurement protrusions 72C are provided at the four corners of the side surface 72 at the edge (short side) along the Z-axis direction. . On the other hand, as shown in FIG. 9A, in the present embodiment, the second measurement protrusions 81C are provided at the edges (long sides) along the Y-axis direction at the four corners of the side surface 81. ing. In this way, the first measurement protrusion 72C and the second measurement protrusion 81C are viewed from the connection direction D2 even if the case 80 is turned upside down (rotated 180 degrees around the axis A) with respect to the base 70. Are arranged so as not to overlap each other.

  According to the above configuration, the plurality of opening ends 83a to 88a with respect to the plurality of opening ends 73d to 78d in any of the two states (postures) of the base 70 (or the case 80) that are reversed with respect to the axis A. Are in the same positional relationship. Further, the first bonding protrusions 72A and 72B and the second bonding protrusions 81A and 81B overlap each other when viewed from the connection direction D2 even when the case 80 is inverted around the axis A with respect to the base 70. For this reason, it becomes possible to normally join the case 80 to the base 70 in either of the two states. Specifically, the case 80 can be normally joined to the base 70 even if the case 80 is turned upside down (rotated 180 degrees around the axis A) with respect to the base 70. As a result, the case 80 can be easily joined to the base 70. In addition, it is possible to prevent erroneous assembly such that the case 80 is joined to the base 70 in an incorrect direction. On the other hand, the first measurement protrusion 72C and the second measurement protrusion 81C do not overlap each other when viewed from the connection direction D2 even if the case 80 is inverted around the axis A with respect to the base 70. That is, the first measurement projection 72C and the second measurement projection 81C do not interfere with each other even if the case 80 is joined to the base 70 in any direction that is in an inverted relationship. For this reason, based on the length of the first measurement projection 72C and the second measurement projection 81C, it can be confirmed whether the hot plate welding has been appropriately performed.

  As shown in FIG. 4 and FIG. 9B, inside the case 80, there are opening ends 83 b to 88 b inside the second communication holes 83 to 88 (second sides opposite to the opening ends 83 a to 88 a). A plurality of accommodation spaces 89P for enclosing each of the opening ends and accommodating the valve bodies 90 for closing the opening ends 83b to 88b, and a plurality of excess spaces 89Q around the accommodation space 89P are provided. . The surplus space 89 </ b> Q is formed by a cylindrical wall portion that forms the accommodation space 89 </ b> P in the case 80 and the inner side surface of the case 80. Accordingly, the surplus space 89Q has a shape that partially follows the accommodation space 89P. The valve body 90 is formed in a cylindrical shape by an elastic member such as rubber. The valve body 90 extends along the connection direction D2 in the state of being accommodated in the accommodation space 89P. The accommodation space 89P is formed in a substantially cylindrical shape in accordance with the shape of the valve body 90. In the present embodiment, the plurality of accommodation spaces 89P corresponding to each of the plurality of opening ends 83b to 88b and the plurality of surplus spaces 89Q are connected to each other.

  The valve body 90 accommodated in each accommodation space 89P is arrange | positioned so that each opening end 83b-88b may be plugged up. Specifically, each of the open ends 83b to 88b has a raised shape raised to the valve body 90 side. By opening the valve body 90 against the respective open ends 83b to 88b having such a raised shape, the open ends 83b to 88b are closed.

  The inner diameter of the accommodation space 89 </ b> P is larger than the diameter of the valve body 90. In addition, a plurality of protrusions 89a are formed on the inner side surface of the accommodation space 89P to contact the side surface 90a of the valve body 90 and fix the valve body 90 to the accommodation space 89P. Each protrusion 89a extends along the X direction. In addition, a plurality (six in this case) of protrusions 89a are provided at regular intervals (60-degree intervals around the central axis of the accommodation space 89P) when viewed from the X direction. Since the side surface 90a of the valve body 90 is supported by the six protrusions 89a, a gap G corresponding to the size of the protrusion 89a is provided between the side surface 90a of the valve body 90 and the inner surface of the accommodation space 89P. (See FIG. 6).

  The cover 100 is a plate-like member joined to the end 80b of the case 80 so as to close the opening 80a of the case 80. The cover 100 also functions as a pressing member that presses the plurality of valve bodies 90 against the case 80 along the connection direction D2 so as to press the plurality of valve bodies 90 against the respective open ends 83b to 88b. The cover 100 is made of, for example, polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE). A method for joining the cover 100 to the end portion 80b of the case 80 is not particularly limited. For example, laser welding, hot plate welding, and fastening using a fastening member such as a bolt can be used. For example, when laser welding is used, the cover 100 is formed of a laser-transmitting resin, the case 80 is formed of a laser-absorbing resin, and the laser is irradiated from the cover 100 side. The boundary portion can be melted and joined.

  The compression rate of the valve body 90 in a state of being pressed against the case 80 by the cover 100 is, for example, the pressure in the second communication holes 83 to 88 (that is, each internal space V communicated with the second communication holes 83 to 88). The pressure is adjusted in advance so that the closing of the open ends 83b to 88b by the valve body 90 is released when the pressure (inside pressure) becomes equal to or higher than a predetermined set value.

  Next, a mechanism for adjusting the pressure in the internal space V will be described. Here, paying attention to the open end 84b shown in FIG. 6, a mechanism for adjusting the pressure in the corresponding internal space V12 will be described. The second communication hole 84 communicates with the corresponding internal space V12 through the first communication hole 74 and the first opening 52a12. For this reason, a pressure equivalent to that of the internal space V12 is applied to a portion that closes the open end 83b of the valve body 90. As described above, the release of the opening end 84b by the valve body 90 is released when the pressure in the corresponding internal space V12 is equal to or higher than a predetermined set value, so that the compression rate of the valve body 90 is increased. It is prescribed. For this reason, when the pressure in the corresponding internal space V12 is less than the set value, the valve closing state in which the opening end 84b is blocked by the valve body 90 is maintained as shown in FIG.

  On the other hand, when the pressure in the internal space V12 rises to be equal to or higher than the set value, a part of the valve body 90 (specifically, a portion that closes the opening end 84b and its peripheral portion) is separated from the opening end 84b. The valve is deformed so as to be separated from the opening end 84b, and the open end state is released. As a result, the gas in the internal space V12 is released from the open end 84b that has been closed. Thereafter, when the pressure in the internal space V12 becomes less than the set value, the valve body 90 returns to the original state, and the opening end 84b is again closed (the state shown in FIG. 6). . With the above opening / closing operation, the pressure adjusting valve 60 can appropriately adjust the pressure in the internal space V12. The mechanism for adjusting the pressure in the internal space V corresponding to the other open ends 83b, 85b to 88b is the same as the mechanism described above.

  As described above, the valve body 90 is fixed to the accommodation space 89P such that a gap G is provided between the inner surface of the accommodation space 89P and the valve body 90. Thereby, when the valve body 90 which closes the opening end 84b of the 2nd communicating hole 84 leaves | separates from the opening end 84b according to the pressure rise in the internal space V (here internal space V12 as an example), it is internal space V12. The gas inside can be appropriately released into the gap G between the valve body 90 and the accommodation space 89P.

  Further, the end surface 89 b of the case 80 in which the opening of the accommodation space 89 </ b> P is formed is separated from the cover 100. As a result, the gas that has escaped into the gap G between the valve element 90 and the accommodation space 89P in the above-described valve open state further flows into the surplus space S (the surplus space 89Q and the surplus space 89Q) between the end surface 89b and the cover 100. It is possible to escape appropriately to the surplus space provided around. Note that the accommodation space 89P and the surplus space 89Q communicate with each other by communicating with the surplus space S.

  Further, the cover 100 is provided with an exhaust port 100a (two exhaust ports 100a in the example of FIG. 4) communicating the surplus space S (that is, the accommodation space 89P) and the external space. When the plurality of exhaust ports 100a are provided in the cover 100, exhaust portions can be dispersed, so that excessive pressure can be suppressed from being applied to a part of the cover 100. However, one exhaust port 100 a may be provided in the cover 100. The exhaust port 100a discharges the gas flowing into the accommodation space 89P from at least one of the plurality of internal spaces V to the external space. Thus, the gas released from the internal space V through the first communication holes 73 to 78 and the second communication holes 83 to 88 is appropriately stored in the external space through the exhaust port 100a without accumulating in the surplus space S. Can be discharged. In particular, by providing the exhaust port 100a in the cover 100, the gas in the surplus space S (relatively high temperature gas) is discharged in a direction away from the power storage module 12 body as much as possible (direction along the connection direction D2). be able to. Thereby, it can suppress effectively that the gas discharged | emitted from the pressure regulation valve 60 has a bad influence on the electrical storage module 12. FIG. Moreover, although the exhaust port 100a is provided in the cover 100 in the position which overlaps with the some valve body 90 seeing from the connection direction D2, it may be provided in the position which does not overlap.

  The exhaust port 100a and the surplus space S will be described in detail with reference to FIGS. FIG. 10 is a cross-sectional view showing a partial configuration of the pressure regulating valve 60. The cross-sectional view of FIG. 10 includes a cross section of a communication path (communication path formed by the second communication hole 86) corresponding to the internal space V24. FIG. 11 is a diagram illustrating a side surface of the pressure regulating valve 60 on the cover 100 side. In FIG. 11, the surplus space S located behind the cover 100 is indicated by a broken line. As shown in FIGS. 10 and 11, the surplus space S corresponds to a communication space that communicates with the exhaust port 100a. The surplus space S has a space portion S1 positioned below the lower end 101 of the exhaust port 100a in the vertical direction (Z direction in the present embodiment). The space portion S1 is a space for accumulating electrolyte that flows into the surplus space S through the gap G together with the gas when the pressure regulating valve 60 is opened. As will be described later, the electrolytic solution is stored in the space portion S1 while being adsorbed and held by the adsorbing member 110B. The volume of the space portion S1 may be equal to or greater than the volume of the electrolytic solution accommodated in one internal space V, or may be equal to or less than the total volume of the electrolytic solution accommodated in all the internal spaces V. In the present embodiment, a single surplus space S having a single space portion S1 communicates with a plurality of exhaust ports 100a. However, for example, a plurality of surplus spaces S partitioned by a partition portion or the like have a plurality of exhausts, respectively. You may communicate with the opening | mouth 100a. In this case, each surplus space S has a space portion S1. Further, a communication space communicating with the exhaust port 100a may be provided separately from the surplus space S in which the plurality of valve bodies 90 are accommodated. In this case, the communication space has a space portion positioned below the lower end 101 of the exhaust port 100a.

  Here, as shown in FIGS. 4, 6, 9 (B) and 10, the electrolyte solution is applied to the outer surface of the cover 100 (the surface opposite to the surface facing the surplus space S). An adsorbing member 110A made of a non-woven fabric for adsorbing is arranged. The adsorption member 110 </ b> A is formed in layers so as to extend along the outer surface of the cover 100. The adsorption member 110A is adhered to the outer surface of the cover 100 by, for example, an adhesive or heat. Further, in each of the surplus spaces 89Q and in the surplus space S, an adsorbing member 110B made of a nonwoven fabric for adsorbing the electrolytic solution is disposed. As an example, the adsorbing member 110B is disposed in the surplus space 89Q by bending a nonwoven fabric so as to follow the shape of the surplus space 89Q. In the power storage module 12, the adsorption member 110B may not be provided. Further, the total amount of the electrolyte solution adsorbed on the adsorbing members 110A and 110B may be equal to or greater than the volume of the electrolyte solution accommodated in one internal space V, and the total electrolyte solution accommodated in all the internal spaces V. It may be below the volume. As an example, the material of the nonwoven fabric constituting the adsorbing members 110A and 110B is rayon, acrylic, nylon, cotton, pulp, and the like.

  As described above, in the power storage module 12, the pressure regulating valve 60 is connected to the opening 50a communicating with the internal space V in which the electrolytic solution is accommodated. The case 80 connected to the internal space V in the pressure regulating valve 60 is formed with a plurality of storage spaces 89P connected to each of the internal spaces V and storing the valve body 90. Case 80 is closed by cover 100. The cover 100 is provided with an exhaust port 100a for discharging gas flowing into the accommodation space 89P from at least one of the plurality of internal spaces V to the outside. Further, an adsorption member 110 </ b> A made of a nonwoven fabric for adsorbing the electrolytic solution is disposed on the outer surface of the cover 100. Therefore, if the internal pressure of the internal space V rises, gas is discharged from the exhaust port 100a of the cover 100 via the accommodation space 89P, and the pressure of the internal space V is adjusted. At this time, the electrolyte may be discharged together with the gas from the exhaust port 100a through the accommodating space 89P, but this electrolyte is adsorbed and held by the adsorption member 110A on the outer surface of the cover 100. Therefore, it is possible to suppress the electrolyte solution discharged to the outside together with the gas from the exhaust port 100a of the cover 100 from diffusing outside. Therefore, reliability is improved.

  In the power storage module 12, the case 80 may be provided with surplus spaces 89Q and S around the accommodation space 89P, and the surplus spaces 89Q and S may be provided with the adsorbing member 110B. In this case, the electrolyte solution that goes to the exhaust port 110a together with the gas through the accommodation space 89P is adsorbed and held by the adsorption member 110B disposed in the surplus spaces 89Q and S around the accommodation space 89P. Therefore, the electrolyte is prevented from being discharged to the outside from the exhaust port 100a of the cover 100 together with the gas. Therefore, reliability is reliably improved.

  Further, in the power storage module 12, the adsorption amount of the electrolytic solution in the adsorption members 110 </ b> A and 110 </ b> B may be equal to or more than the volume of the electrolytic solution accommodated in one internal space V. In this case, even if all of the electrolytic solution accommodated in one internal space V leaks from the internal space V, it is possible to suppress the deterioration of reliability.

  The above embodiment exemplifies one embodiment of the power storage module according to the present invention, and the present invention is not limited to the power storage module 12 described above. The power storage module according to the present invention can arbitrarily change the power storage module 12 without departing from the spirit of each claim.

  For example, in the pressure regulating valve 60, the first measurement protrusion 72C and the second measurement protrusion 81C may be omitted.

  In the present embodiment, one valve body 90 is configured to block one open end (any one of the open ends 83b to 88b). However, for example, a single valve body is used using a plate-shaped valve body. A configuration in which the plurality of opening ends are closed (that is, a configuration in which one valve body is commonly used for the plurality of opening ends) may be employed. The case 80 may be integrated with the base 70. In this case, the base in which the case 80 is integrated has the surplus space S and the space portion S1.

  FIG. 12 is a view showing a side surface on the cover 100 side of the pressure regulating valve 60 according to the modification. The pressure regulating valve 60 of this modification has the same configuration as the pressure regulating valve 60 shown in FIG. 3 and the like except that the position of the exhaust port 100a is different. In the pressure regulating valve 60 of this modification, the lower end 101 of the exhaust port 100a is located above the center 102 of the pressure regulating valve 60 in the vertical direction (Z direction in the present embodiment). The center 102 corresponds to the midpoint of the maximum dimension of the pressure regulating valve 60 in the vertical direction. In this case, the volume of the space portion S1 located below the lower end 101 of the exhaust port 100a can be made relatively large. Therefore, an electrolytic solution having a larger volume can be stored in the space portion S1.

  Further, the position of the lower end 101 of the exhaust port 100a in the vertical direction may be different for each exhaust port 100a. In this case, the single space portion S1 may be located below the lowermost end 101 located at the lowest position among the lower ends 101 of the plurality of exhaust ports 100a, or the plurality of space portions S1 separated from each other may be You may each be located under the lower end 101 of the some exhaust port 100a. When the single space portion S1 is provided for the plurality of exhaust ports 100a, the space portion S1 can be shared, so that an electrolytic solution having a larger volume can be stored in the space portion S1.

  DESCRIPTION OF SYMBOLS 12 ... Power storage module, 30 ... Laminated body, 30a ... Side surface, 32 ... Bipolar electrode, 34 ... Electrode plate, 34a ... Edge, 36 ... Positive electrode, 38 ... Negative electrode, 50 ... Frame, 50a ... Opening, 60 ... Pressure adjustment Valve: 70 ... Base, 80 ... Case, 89P ... Accommodating space, 90 ... Valve body, 100 ... Cover, 100a ... Exhaust port, 89Q, S ... Excess space, 110A, 110B ... Adsorption member, V ... Internal space.

Claims (3)

A laminate having a plurality of bipolar electrodes each including an electrode plate, a positive electrode provided on one surface of the electrode plate, and a negative electrode provided on the other surface of the electrode plate;
A frame body that holds an edge of the electrode plate and is provided with openings that communicate with a plurality of internal spaces between the bipolar electrodes adjacent to each other in the stacked body;
A pressure regulating valve connected to the opening;
An electrolyte contained in the internal space;
With
The pressure regulating valve includes a case connected to the internal space through the opening, a plurality of valve bodies accommodated in the case, and a cover provided on the case so as to close the case. Have
The case is formed with a plurality of storage spaces that communicate with each of the internal spaces through the openings and store the valve bodies, respectively.
The cover is provided with an exhaust port for discharging gas flowing into the housing space from at least one of the plurality of internal spaces to the outside.
An adsorption member made of a nonwoven fabric for adsorbing the electrolytic solution is disposed on the outer surface of the cover.
Power storage module. In the case, a surplus space around the accommodation space is formed,
The adsorbing member is arranged in the surplus space,
The power storage module according to claim 1. The adsorption amount of the electrolyte solution in the adsorption member is equal to or greater than the volume of the electrolyte solution accommodated in one internal space.
The power storage module according to claim 1 or 2.

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