JP2018206679A - Power storage module - Google Patents

Abstract

To provide a power storage module capable of aiming for uniform valve opening pressure of a pressure regulator valve.SOLUTION: A power storage module 12 includes a frame body 50 provided with an opening 50a communicating with multiple internal spaces V between adjoining bipolar electrodes 32, and a pressure regulator valve 60 for connection with the opening 50a. The pressure regulator valve 60 has a base member connected with the opening 50a, and provided with an end face 71 on the opening 50a side and an end face 82 on the opposite side to the end face 71, and a valve body 90 placed on the end face 82 side of the base member. The base member has multiple continuous holes penetrating from the opening end 75a formed in the end face 71 to the opening end 83b formed in the end face 82, and communicating with the multiple internal spaces V, respectively, via the opening 50a, and multiple spurs 84 surrounding each opening end 83b and projecting from the end face 82. The valve body 90 is in contact with the tips 84a of the multiple spurs 84, and a space is formed between the end face 82 and the valve body 90.SELECTED DRAWING: Figure 6

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. The bipolar electrode is laminated via an electrolyte layer made of a separator impregnated with an electrolytic solution. The battery is provided with a tube penetrating the seal portion for each internal space. 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

  By the way, since the space | interval of adjacent internal spaces is narrow in a bipolar battery, it is difficult to provide a pressure regulation valve with respect to each internal space individually. Therefore, it is conceivable to provide one common pressure regulating valve for a plurality of internal spaces. For example, the structure which seals each gas exhaust port of several internal space with one valve body (for example, elastic members, such as a rubber plate), can be considered. However, when the pressure regulating valve having such a configuration is used, the reaction force received from the valve body varies depending on the position of the gas discharge port, and therefore, the valve opening pressure at which the valve body opens may vary. As a result, there may arise a problem that the pressure adjustment of a part of the internal space is not appropriately performed.

  An object of this invention is to provide the electrical storage module which can aim at equalization of the valve opening pressure of a pressure regulating valve.

  A power storage module according to one aspect of the present invention includes a laminate in which a bipolar electrode 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 is laminated, A pressure regulating valve, comprising: a frame body that holds an edge of the electrode plate and is provided with an opening that communicates with a plurality of internal spaces between adjacent bipolar electrodes in the laminate; and a pressure regulating valve that is connected to the opening. Is a base member provided with a first end surface on the opening side and a second end surface opposite to the first end surface, an elastic member disposed on the second end surface side of the base member, and an elastic member A pressing member that presses against the base member, the base member penetrating from the first opening end formed on the first end surface to the second opening end formed on the second end surface, and through the opening. A plurality of communication holes communicating with each of the plurality of internal spaces, A plurality of projecting portions that surround the open end and project from the second end surface, the elastic member is in contact with the tip portions of the plurality of projecting portions, and a space is formed between the second end surface and the elastic member. Yes.

  In a configuration in which a plurality of communication holes (gas discharge ports) are sealed with one elastic member (valve element), when the pressure in the internal space increases, the gas pushes up the elastic member and deforms, thereby discharging the gas from the communication holes. Is done. When the second end surface of the base member is in contact with the elastic member, that is, when the base member does not have a protruding portion, the elastic member is in close contact between the base member and the pressing member. Therefore, the center side of the elastic member viewed from the surface in contact with the second end surface is more easily disturbed by the base member than the outer edge side. That is, the central side of the elastic member is less likely to be deformed than the outer edge side, so that the central side of the elastic member is less likely to deform than the outer edge side. Therefore, the valve opening pressure of the communication hole located on the central side of the elastic member tends to be higher than the valve opening pressure of the communication hole located on the outer edge side of the elastic member. As a result, it is considered that the valve opening pressure varies.

  The base member of the power storage module has a plurality of protrusions that surround the second opening end of each communication hole and protrude from the second end surface, and the elastic member contacts the distal ends of the plurality of protrusions, A space is formed between the second end surface and the elastic member. Thus, each communicating hole is block | closed indirectly because an elastic member contacts the front-end | tip part of a protrusion part. The gas discharged in response to the pressure increase in the internal space passes through the second opening end of the communication hole and is discharged from between the tip of the protruding portion and the elastic member pushed up by the gas. Since the protrusions are provided, a space is formed between the elastic member and the second end surface, and similarly, a portion serving as a refuge for the deformation of the elastic member is formed around each protrusion. Is done. As a result, the difference depending on the position can be reduced with respect to the ease of deformation of the elastic member. Therefore, the valve opening pressure of the pressure regulating valve can be made uniform with respect to each communication hole.

  In one form, the second end surface and the elastic member may be separated from each other. According to this configuration, the space between the second end surface and the elastic member functions as a flow path for discharging the gas discharged from between the front end portion of the protruding portion and the elastic member to the outside. Accordingly, since it is not necessary to form a flow path or the like in the base member, the structure of the pressure adjustment valve can be simplified.

  In one form, all the distance between adjacent 2nd opening ends may be the same. According to this structure, since the protrusion part surrounding the 2nd opening end is equally arrange | positioned in a 2nd end surface, the difference depending on a position can be further reduced regarding the ease of a deformation | transformation of an elastic member.

  In one embodiment, the pressing member is disposed so as to cover the elastic member and the base member, and the pressing member is provided with an exhaust hole that communicates the space defined by the pressing member, the elastic member, and the base member with the outside. It may be done. According to this structure, the gas discharged | emitted according to the pressure rise of internal space flows in into the space defined by a press member, an elastic member, and a base member, and is discharged | emitted outside from an exhaust hole. Therefore, the gas generated in the internal space can be discharged to the outside with a simple configuration.

  In one form, a base member may have the 1st base member containing the 1st end face, and the 2nd base member containing the 2nd end face. In this case, since the second opening end and the protruding portion are provided on the second base member, the pressure regulating valve can be inspected using a unit including the second base member, the elastic member, and the pressing member. For example, the value of the valve opening pressure can be confirmed by sending air into the communication hole from the side opposite to the second end surface of the second base member (the side connected to the first base member). Therefore, the pressure regulating valve can be easily inspected before the pressure regulating valve is assembled.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical storage module which can aim at equalization of the valve opening pressure of a pressure regulating valve is provided.

It is a schematic sectional drawing which shows an electrical storage apparatus provided with the electrical storage module which concerns on one Embodiment of this invention. It is a schematic sectional drawing which shows the electrical storage module which comprises the electrical storage apparatus of FIG. It is a schematic perspective view which shows the electrical storage module of FIG. FIG. 4 is an enlarged plan view of a part of the power storage module of FIG. 3. It is a disassembled perspective view of the pressure regulation valve connected to opening of a frame. It is a schematic sectional drawing which shows the structure of a pressure regulating valve. It is a top view which shows the end surface by the side of (A) frame body opening of a 1st base member, and the (B) 2nd base member side. It is a top view which shows the end surface by the side of (A) 1st base member of a 2nd base member, and the end surface by the side of (B) valve body, (C) is sectional drawing along the IX-IX line of (B). . (A) is a figure which shows a valve closing state, (B) is a figure which shows a valve opening state. (A) is a schematic sectional drawing which shows the pressure regulation valve sealed with one valve body with respect to several internal space, (B) is a figure which shows reaction force distribution in the pressure regulation valve of (A). . It is a figure which shows reaction force distribution in the pressure regulation valve of the electrical storage module of FIG.

  Hereinafter, various embodiments will be described in detail with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  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 of (three in the present embodiment) 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, for example, a secondary battery such as a nickel metal hydride battery or a lithium ion secondary battery, but may be an electric double layer capacitor. In the following description, a nickel metal hydride 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, each of the restraining plates 16A and 16B and the insulating film 22 has, 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 the restraining plates 16A and 16B have a rectangular shape when viewed from the stacking direction D1, the insertion holes H1 and the insertion holes H2 are located at the corners of the restraining plates 16A and 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 to 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 in which a plurality of bipolar electrodes (electrodes) 32 are stacked. 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 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, in the first resin portion 52, as in the case of the electrode plate 34 of each bipolar electrode 32, the edge portions 34 a of the electrode plates 34 arranged on both sides of the laminate 30 are also embedded in the first resin portion 52. Is retained. Thereby, between the electrode plates 34 and 34 adjacent to each other in the stacking direction D <b> 1, a plurality of internal spaces V that are airtightly partitioned by the electrode plates 34 and 34 and the first resin portion 52 are formed. 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 a rectangular metal foil made of nickel, for example. 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.

  FIG. 3 is a schematic perspective view showing the power storage module of FIG. 4 is an enlarged plan view of a part of the power storage module of FIG. 3 (a peripheral region of one opening 50a). 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.

  The side surface 50s of the frame 50 has a main body region 50s1 and a protruding region 50s2. Each of the main body region 50s1 and the protruding region 50s2 has a rectangular shape, for example. An opening 50a is provided in the main body region 50s1. The opening 50a functions as a liquid injection port for injecting an electrolytic solution into each internal space V, and after the electrolytic solution is injected, a pressure regulating valve 60 (for adjusting the pressure in each internal space V) It functions as a connection port in detail). In the present embodiment, the frame 50 has a plurality (here, four) of openings 50a (openings 50a1 to 50a4). Specifically, two openings 50 a are provided on each side surface 50 s facing the longitudinal direction (X direction) of the frame body 50.

  The main body region 50 s 1 has an edge E extending in a direction (Y direction) intersecting the stacking direction D 1 of the bipolar electrode 32. The protruding region 50s2 protrudes from the edge E so as to be separated from the opening 50a in the stacking direction D1 of the bipolar electrode 32. In the present embodiment, the pair of protruding regions 50s2 are arranged so as to sandwich the opening 50a. The protruding region 50s2 is provided with a length that extends beyond the entire length of the opening 50a along the edge E and protrudes from both sides of the opening 50a.

  As shown in FIG. 4, one opening 50 a may have 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 52a communicates with the internal space V between the adjacent bipolar electrodes 32 and the second opening 54a. The first resin part 52 is provided with a plurality of first openings 52a, and the second resin part 54 is provided with a single second opening 54a that extends so as to cover the plurality of first openings 52a. . 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, 24 internal spaces V are formed in the power storage module 12, and one opening 50 a communicates with 6 internal spaces V. That is, each internal space V communicates with any one of the four openings 50a1 to 50a4. As shown in FIG. 4, in one opening 50a (here, opening 50a1 as an example), six first openings 52a are arranged along the stacking direction D1. All the distances between the adjacent first openings 52a in the stacking direction D1 are the same. The six first openings 52a are arranged point-symmetrically when viewed from the opening direction (X direction) of the opening 50a. Note that the distances between the adjacent first openings 52a may not be the same. Further, since the position of the first opening 52a is different for each opening 50a, the point-symmetric reference point is different for each opening 50a.

  FIG. 5 is an exploded perspective view of the pressure regulating valve 60 connected to the opening 50 a of the frame body 50. FIG. 6 is a schematic cross-sectional view showing the configuration of the pressure regulating valve 60. As shown in FIGS. 5 and 6, the pressure regulating valve 60 includes a first base member 70, a second base member 80, a valve body 90 (elastic member), and a cover member 100 (pressing member). doing.

  The first base member 70 has a substantially rectangular parallelepiped outer shape, and is formed of, for example, polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene sulfide (modified PPE), or the like. The first base member 70 has an end face 71 (first end face) on the opening 50a side, a connecting portion 72 including the end face 71, and an end face 73 on the opposite side to the end face 71, and is connected to the opening 50a. The The end surface 71 faces the side surface 52 s of the first resin portion 52, and the end surface 73 faces the second base member 80. The connecting portion 72 has a shape corresponding to the second opening 54a. The first base member 70 is opened when a part or all of the contact portion between the end surface 71 and the side surface 52s of the first resin portion 52 is welded in a state where the connection portion 72 is inserted into the second opening 54a. It is fixed with respect to 50a. The end surface 71 and the side surface 52s are welded by, for example, hot plate welding, laser transmission welding, ultrasonic welding, or the like.

  7A is a plan view showing an end surface 71 of the first base member 70 on the opening 50a side, and FIG. 7B shows an end surface 73 of the first base member 70 on the second base member 80 side. It is a top view. As shown in FIGS. 6 and 7, the first base member 70 is provided with a plurality of first communication holes 74 that penetrate from the end surface 71 to the end surface 71. Each first communication hole 74 communicates with one internal space V through one corresponding first opening 52a. The first communication hole 74 includes a first communication portion 75 that is a portion of the first communication hole 74 on the end surface 71 side, and a second communication portion 76 that is a portion of the first communication hole 74 on the end surface 73 side.

  The first communication part 75 is formed in a rectangular cross section. A substantially rectangular parallelepiped space S <b> 1 is formed by the first communication portion 75. An opening end 75a (first opening end) on the opening 50a side of the first communication portion 75 is defined as a rectangular first opening 52a when viewed from the connection direction D2 (X direction) between the opening 50a and the first base member 70. It is formed in a size that includes it. On the other hand, the opening end 75b on the side connected to the second communication portion 76 of the first communication portion 75 is formed in a circular cross section. The inner diameter of the open end 75b is the same as the width d1 of the open end 75a in the stacking direction D1.

  The second communication portion 76 is formed in a circular cross section. The second communication portion 76 penetrates from the opening end 75 b of the first communication portion 75 to the opening end 76 a on the end surface 73 side of the second communication portion 76. The open end 76a is formed in a circular shape. The inner diameter d3 of the opening end 76a is larger than the inner diameter of the opening end 75b (that is, the width d1 of the opening end 75a in the stacking direction D1) (d3> d1). That is, the second communication portion 76 forms a tapered space S2 having an inner diameter that increases from the opening end 75b toward the opening end 76a. In the present embodiment, as shown in FIG. 6, the second communication portion 76 extends such that the center position of the opening end 76 a is located above the center position of the opening end 75 b. Such a 2nd communication part 76 may be formed by injection molding etc., for example.

  8A is a plan view showing the end surface 81 of the second base member 80 on the first base member 70 side, and FIG. 8B shows the end surface 82 of the second base member 80 on the valve body 90 side. FIG. FIG. 8C is a cross-sectional view taken along line IX-IX in FIG. As shown in FIGS. 6 and 8, the second base member 80 includes an end surface 81 facing the end surface 73 of the first base member 70, an end surface (second end surface) 82 opposite to the end surface 81, and an end surface. A plurality of second communication holes 83 penetrating from 81 to the end surface 82 and a plurality of projecting portions 84 projecting from the end surface 82 are provided. The external shape of the second base member 80 is a substantially rectangular parallelepiped shape. The end surface 81 is joined to the end surface 73 of the first base member 70. The end surface 81 and the end surface 73 can be welded by, for example, hot plate welding. In the present embodiment, the second base member 80 is formed slightly larger than the first base member 70 when viewed from the connection direction D2, but the second base member 80 is the same as the first base member 70. It may be formed in a size or may be formed smaller than the first base member 70.

  The second communication hole 83 is formed in a circular cross section. Each second communication hole 83 communicates with one internal space V via a corresponding first communication hole 74. That is, a plurality of communication holes penetrating from the end surface 71 to the end surface 82 are formed by the first communication hole 74 of the first base member 70 and the second communication hole 83 of the second base member 80.

  The inner diameter of the opening end 83a on the first base member 70 side coincides with the inner diameter d3 of the opening end 76a of the first communication hole 74. The first base member 70 and the second base member 80 are joined so that the opening end 76a and the opening end 83a corresponding to each other as seen from the connection direction D2 overlap each other. The inner diameter d4 of the opening end 83b (second opening end) on the valve body 90 side of the second communication hole 83 is smaller than the inner diameter of the opening end 83a (that is, the inner diameter d3 of the opening end 76a) (d4 < d3). That is, the second communication hole 83 forms a tapered space S3 having an inner diameter that decreases from the opening end 83a toward the opening end 83b. All the distances L between the adjacent open ends 83b are the same. Further, the plurality of opening ends 83 b are arranged so that the distance L is as large as possible in the end face 82. Such a second communication hole 83 can be formed by, for example, injection molding or the like. Note that the inner diameter of the opening end 83a and the inner diameter d3 of the opening end 76a do not have to coincide with each other. For example, when the inner diameter of the open end 83a is made smaller than the inner diameter d3, an effect of allowing a positional shift at the time of joining can be achieved. Moreover, it is preferable that the distances L between the adjacent open ends 83b are all the same, but the distances L may not be the same.

  As shown in FIGS. 7B and 8A, the plurality of opening ends 76a and the plurality of opening ends 83a are all arranged symmetrically with respect to the axis A. According to this configuration, in any one of the two states of the first base member 70 (or the second base member 80) that are reversed with respect to the axis A, the plurality of opening ends 83a with respect to the plurality of opening ends 76a The arrangement is the same. For this reason, it becomes possible to normally join the second base member 80 to the first base member 70 in either of the two states. That is, the second base member 80 can be normally joined to the first base member 70 even when the second base member 80 is turned upside down (rotated 180 degrees around the axis A) with respect to the first base member 70. . As a result, the second base member 80 can be easily joined to the first base member 70. In addition, it is possible to prevent erroneous assembly such that the second base member 80 is joined to the first base member 70 in an incorrect direction.

  As shown in FIGS. 6, 8B, and 8C, each protrusion 84 has a substantially cylindrical outer shape and is formed so as to surround one open end 83b. The protruding portion 84 protrudes from the end surface 82 toward the valve body 90 along the connection direction D <b> 2, and the distal end portion 84 a on the valve body 90 side of the protruding portion 84 contacts the valve body 90. Thus, when the front-end | tip part 84a and the valve body 90 contact, each open end 83b is in the state closed indirectly. The end surface 82 of the second base member 80 and the valve body 90 are separated from each other. When viewed from the connection direction D2, the height (dimension in the connection direction D2) T of the protrusion 84 is, for example, about 0.3 mm to 1.5 mm. In the present embodiment, the height T of the protrusion 84 is 0.4 mm. The height T of the protruding portion 84 is not limited to the above-described range, and can be appropriately changed according to the hardness of the valve body 90. The inner diameter of the protruding portion 84 coincides with the inner diameter d4 of the opening end 83b. In addition, since each protrusion part 84 should just surround the opening end 83b and is mutually spaced apart, the internal diameter of the protrusion part 84 may be larger than the internal diameter d4 of the opening end 83b. The protrusion 84 can be formed by, for example, injection molding or the like.

  The valve body 90 is formed of an elastic member such as rubber. The valve body 90 has a rectangular parallelepiped shape, for example. The valve body 90 is disposed so as to be in contact with the distal end portions 84 a of the plurality of projecting portions 84 provided on the second base member 80. By disposing the valve body 90 in this way, a space S5 is formed between the end surface 82 of the second base member 80 and the valve body 90.

  The cover member 100 is a box-shaped member having a rectangular plate-like bottom wall portion 101 and a side wall portion 102 provided at an edge of the bottom wall portion 101 and extending along the connection direction D2. The cover member 100 is made of, for example, polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE). On the inner side of the bottom wall portion 101, a groove portion 103 that is recessed in a concave shape for positioning the valve body 90 is provided. The cover member 100 accommodates the valve body 90 in the groove 103 and functions as a pressing member for pressing the valve body 90 against the protruding portion 84 of the second base member 80. The cover member 100 is disposed so as to cover the second base member 80 and the valve body 90, and a space S <b> 4 is formed by the cover member 100, the valve body 90, and the second base member 80. The space S4 communicates with the space S5 between the end face 82 and the valve body 90. An exhaust hole 104 penetrating the bottom wall portion 101 in the connection direction D2 is provided in a region between the side wall portion 102 and the groove portion 103 of the bottom wall portion 101 as viewed from the connection direction D2. The exhaust hole 104 communicates with the space S4. That is, the exhaust hole 104 communicates with the space S5 via the space S4.

  As shown in FIG. 6, the end 102 a of the side wall 102 is fixed to the second base member 80 in a state where the valve body 90 is positioned and accommodated in the groove 103 of the cover member 100. A method for fixing the end portion 102a and the second base member 80 is not particularly limited. For example, laser welding, hot plate welding, and fastening using a fastening member such as a bolt may be used. For example, when laser welding is used, the cover member 100 is formed of a laser-transmitting resin, the second base member 80 is formed of a laser-absorbing resin, and the laser is irradiated from the cover member 100 side, whereby the second The boundary portion between the base member 80 and the cover member 100 can be melted and joined.

  Here, the thickness (width in the X direction) of the valve body 90 at the normal time (non-compressed) is larger than the height d5 from the bottom surface 103a of the groove portion 103 to the end portion 102a of the side wall portion 102. That is, the compression rate of the valve body 90 is defined by the height d5. The compression rate of the valve body 90 is set such that, for example, the pressure in the protrusion 84 (that is, the pressure in the second communication hole 83 or the pressure in the internal space V communicated with the second communication hole 83) is determined in advance. When the value is equal to or greater than the value, adjustment is performed in advance so that the blocking of the protruding portion 84 by the valve body 90 (that is, the blocking of the opening end 83b) is released.

  Next, the principle of adjusting the pressure in the internal space V will be described. As described above, each of the second communication holes 83 communicates with the corresponding internal space V. Therefore, a portion of the valve body 90 that closes the tip end portion 84a of the protrusion 84 is a second corresponding to the protrusion 84. A pressure equivalent to that of the two communication holes 83 and the internal space V is applied. Here, the release of the blocking of the tip 84a by the valve body 90 is performed when the pressure in the corresponding internal space V becomes equal to or higher than a predetermined set value, so that the compression rate of the valve body 90 is It is prescribed. For this reason, when the pressure in the corresponding internal space V is less than the set value, the tip end portion 84a (open end 83b) of the protruding portion 84 is blocked by the valve body 90, as shown in FIG. The closed valve state is maintained.

  On the other hand, when the pressure in the corresponding internal space V rises and becomes equal to or higher than the set value, as shown in FIG. 9B, a part of the valve body 90 (specifically, the tip end portion 84a). And the peripheral portion) are deformed so as to be separated from the tip portion 84a, and the valve body 90 is released from the closed state of the tip portion 84a (open end 83b). As a result, the opening end 83b corresponding to the projecting portion 84 whose occlusion has been released communicates with the space S4, and the gas in the corresponding internal space V passes through the opening end 83b and passes between the tip end portion 84a and the valve body 90. It is discharged to the space S4 from between. The gas discharged into the space S4 is discharged to the outside through the exhaust hole 104 provided in the cover member 100. Thereafter, when the pressure in the internal space V becomes less than the set value, the leading end portion 84a of the projecting portion 84 is closed by the valve body 90 (see FIG. 9A). . With the above opening / closing operation, the pressure adjusting valve 60 appropriately adjusts the pressure in the internal space V.

  Next, the operation of the power storage module 12 will be described with reference to FIGS. 10 and 11.

  In the bipolar battery as described above, since the interval between adjacent internal spaces is narrow, it is difficult to provide a pressure regulating valve individually for each internal space. Therefore, the inventors of the present application have considered a configuration in which a plurality of internal spaces are sealed with a single valve element. Specifically, like the pressure regulating valve 160 shown in FIG. 10 (A), the plurality of second communication holes 183 formed in the second base member 180 are closed by one valve body 190. In the pressure regulating valve 160, the second base member 180 does not have a protruding portion, and the end surface 182 of the second base member 180 is in contact with the valve body 190. The opening end 183 b of the second communication hole 183 on the valve body 190 side is directly closed by the valve body 190.

  However, when the pressure regulating valve 160 having such a configuration is used, as shown in FIG. 10B, the reaction force received by the valve body 190 increases toward the center side, and is positioned at the center side of the valve body 190. It is found that the valve opening pressure of the second communication hole 183 (opening end 183b) tends to be higher than the valve opening pressure of the second communication hole 183 (opening end 183b) located on the outer edge side of the valve body 190. It was. As a result, it was considered that the valve opening pressure may vary.

  The inventors of the present application diligently studied the cause of variation in the reaction force received by the valve body 190 when the plurality of second communication holes 183 are sealed by the single valve body 190. As a result, the valve body 190 is sandwiched between the second base member 180 and a cover member (not shown) that presses the valve body 190, so that the surface of the valve body 190 comes into contact with the end surface 182. The center side of the valve body 190 as viewed is focused on that the deformation of the valve body 190 is likely to be hindered by the end face 182 compared to the outer edge side. That is, the central side of the valve body 190 thought that there may be a cause that there are few places used as a refuge for the valve body 190 to deform | transform.

  Therefore, in the power storage module 12 according to the present embodiment, as shown in FIGS. 8C and 9, the second base member 80 surrounds the open end 83 b of each second communication hole 83 and from the end surface 82. A plurality of projecting portions 84 that project is provided, the valve body 90 is brought into contact with the tip portions 84 a of the plurality of projecting portions 84, and a space S 5 is formed between the end surface 82 and the valve body 90. In this manner, by forming the space S5 between the valve body 90 and the end face 82, similarly, a portion serving as a refuge for the deformation of the valve body 90 is formed around each protrusion 84. it is conceivable that. As a result, as shown in FIG. 11, variation in reaction force received by the valve body 90 was reduced. That is, in the power storage module 12 of the present embodiment, the position-dependent difference can be reduced with respect to the ease of deformation of the valve body 90, and the pressure regulating valve 60 is opened with respect to each second communication hole 83. The pressure can be made uniform.

  In general, it is known that the ease of deformation of the valve body depends on the coefficient of friction of the valve body. For this reason, when setting the valve opening pressure of the pressure regulating valve, it is necessary to consider the friction coefficient of the valve body. On the other hand, in the pressure regulating valve 60, the contact area between the second base member 80 and the valve body 90 is reduced by providing the protruding portion 84. For this reason, the influence by the friction coefficient of the valve body 90 is reduced, and the valve opening pressure can be easily set.

  Further, the end face 82 and the valve body 90 are separated from each other. Thereby, the space between the end surface 82 and the valve body 90 functions as a flow path for discharging the gas discharged from between the tip end portion 84a of the protruding portion 84 and the valve body 90 to the outside. Therefore, since it is not necessary to form a flow path or the like in the second base member 80 or the valve body 90, the structure of the pressure adjustment valve 60 can be simplified.

  Further, as shown in FIG. 8B, the distances between the adjacent open ends 83b are all the same. Thereby, since the protrusion part 84 surrounding the opening end 83b is equally arrange | positioned in the end surface 82, the difference depending on a position can be further reduced regarding the ease of deformation | transformation of the valve body 90. FIG. Further, the plurality of opening ends 83 b are arranged so that the distance L is as large as possible in the end face 82. Thereby, the influence which acts on the adjacent opening end 83b can be reduced. For example, even if a part of the valve body 90 that closes the one open end 83b is deformed due to an increase in pressure in the internal space V, the deformation may extend to another part of the valve body 90 that closes the adjacent open end 83b. It is suppressed. Therefore, the influence on the adjacent opening end 83b can be reduced.

  9, the cover member 100 is disposed so as to cover the valve body 90 and the second base member 80, and the cover member 100 includes the cover member 100, the valve body 90, and the second base. An exhaust hole 104 that communicates the space S4 defined by the member 80 and the outside is provided. Thereby, the gas discharged according to the pressure increase in the internal space V flows into the space S4 and is discharged to the outside through the exhaust hole 104. Therefore, the gas generated in the internal space V can be discharged to the outside with a simple configuration.

  Further, the pressure regulating valve 60 includes a first base member 70 including an end surface 71 and a second base member 80 including an end surface 82. Thereby, since the opening end 83b and the protrusion 84 are provided in the second base member 80, the pressure regulating valve 60 is inspected using a unit including the second base member 80, the valve body 90, and the cover member 100. It can be carried out. For example, the value of the valve opening pressure can be confirmed by sending air into the second communication hole 83 from the side opposite to the end surface 82 (end surface 81 side) of the second base member 80. Therefore, the pressure control valve 60 can be easily inspected before the pressure control valve 60 is assembled.

  As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment.

  For example, the end surface 82 of the second base member 80 and the valve body 90 may not be completely separated from each other, and the end surface 82 and a part of the valve body 90 may be in contact with each other.

  Further, in addition to the projecting portion 84, a column portion for the purpose of separating the end surface 82 and the valve body 90 may be provided so as to project from the end surface 82. In this case, the pillar portion may be provided between the adjacent protruding portions 84. By providing the column portion in this way, it is possible to prevent the space between the end surface 82 and the valve body 90 from being blocked by the bending of the valve body 90 or the like.

  In the above-described embodiment, the configuration in which the space S5 between the end face 82 and the valve body 90 functions as a gas flow path has been described. However, the gas flow path is provided on the end face 82 of the second base member 80 or the valve body 90. A groove portion may be formed.

  Moreover, although the said embodiment demonstrated the example in which the number of the 1st communicating holes 74 and the 2nd communicating holes 83 was respectively 6, the number of the 1st communicating holes 74 and the 2nd communicating holes 83 is the inside space V. It can be appropriately changed according to the number. For example, in the configuration in which the power storage module 12 has 56 internal spaces and one opening 50a communicates with 14 internal spaces V, the number of first communication holes 74 and second communication holes 83 is respectively It can be 14.

  In the above embodiment, the exhaust hole 104 is formed so as to penetrate the bottom wall 101 in the connection direction D2 (X direction). However, the exhaust hole 104 extends through the side wall 102 in the stacking direction D1 (Y direction). You may form so that it may penetrate. Further, the exhaust hole 104 may be formed in the second base member 80.

  Moreover, in the said embodiment, although the pressure regulation valve 60 had the 1st base member 70 and the 2nd base member 80, the 1st base member 70 and the 2nd base member 80 are comprised integrally as one base member. May be.

  In the above-described embodiment, the example in which the distances between the first openings 52a are all the same has been described, but the distances between the first openings 52a may not be the same. In this case, the distance L between the open ends 83b can be adjusted by bending the first communication hole 74 of the first base member 70 and the second communication hole 83 of the second base member 80.

  DESCRIPTION OF SYMBOLS 12 ... Power storage module, 30 ... Laminated body, 30a ... Side surface, 32 ... Bipolar electrode, 34a ... Edge, 34 ... Electrode plate, 34a ... Edge, 50 ... Frame, 50a ... Opening, 60 ... Pressure regulating valve, 70 ... 1st base member, 71 ... End face (first end face), 72 ... Connection part, 73 ... End face, 74 ... 1st communicating hole, 75a ... Open end (1st open end), 80 ... 2nd base member, 82 ... end face (second end face), 83 ... second communication hole, 83b ... open end (second open end), 84 ... projecting portion, 90 ... valve body, 100 ... cover member (pressing member), 104 ... exhaust hole, D1 ... stacking direction, D2 ... connection direction, L ... distance, S4 ... space, V ... internal space.

Claims (5)

A laminate in which a bipolar electrode 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 is laminated;
A frame 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 laminate;
A pressure regulating valve connected to the opening;
With
The pressure regulating valve is connected to the opening, and has a base member provided with a first end surface on the opening side and a second end surface opposite to the first end surface, and on the second end surface side of the base member. An arranged elastic member, and a pressing member that presses the elastic member against the base member,
The base member penetrates from a first opening end formed on the first end surface to a second opening end formed on the second end surface, and communicates with each of the plurality of internal spaces through the opening. A plurality of projecting portions that surround each of the second opening ends and project from the second end face,
The elastic member is in contact with tip portions of the plurality of protrusions;
A power storage module, wherein a space is formed between the second end surface and the elastic member.   The power storage module according to claim 1, wherein the second end surface and the elastic member are separated from each other.   The power storage module according to claim 1 or 2, wherein all the distances between adjacent second opening ends are the same. The pressing member is disposed so as to cover the elastic member and the base member,
The said pressing member is provided with the exhaust hole which connects the space and the exterior which are defined by the said pressing member, the said elastic member, and the said base member, The any one of Claims 1-3. Power storage module.   The power storage module according to any one of claims 1 to 4, wherein the base member includes a first base member including the first end surface and a second base member including the second end surface.