JP7057255B2 - Power storage module and power storage module manufacturing method - Google Patents

Description

The present invention relates to a power storage module and a method for manufacturing a power storage module.

As a conventional battery module, for example, a thin battery as described in Patent Document 1 is known. The thin battery described in Patent Document 1 is arranged so as to surround a bipolar electrode having a positive electrode, a negative electrode and a current collector, an electrolyte layer containing a separator and an electrolytic solution, and a positive electrode on one main surface of the current collector. A first seal portion, a second seal portion arranged so as to surround the negative electrode on the other main surface of the current collector, and a tube penetrating the second seal portion are provided. One end of the tube faces the internal space defined by the separator, the current collector and the second seal portion, and the other end of the tube faces the external space of the second seal portion. The gas generated inside the battery is discharged to the outside of the battery via the tube.

Japanese Unexamined Patent Publication No. 2010-288451

In the above-mentioned prior art, the tube functions as a valve for discharging gas in the internal space when the pressure in the internal space rises. On the other hand, when the gas in the internal space is discharged, the electrolytic solution may be discharged to the outside. When the electrolytic solution is discharged to the outside, the electrolytic solution in the internal space may decrease and the battery characteristics may deteriorate. Therefore, it is desirable to reduce the amount of the electrolytic solution discharged.

Therefore, an object of the present invention is to provide a power storage module capable of reducing the amount of electrolytic solution discharged, and a method for manufacturing the power storage module.

The power storage module according to the present invention is arranged so as to surround an electrode laminate including a plurality of bipolar electrodes laminated to each other, an electrolytic solution arranged in a plurality of internal spaces provided in the electrode laminate, and an electrode laminate. A frame body having a plurality of first communication holes communicated with each of the plurality of internal spaces, and a pressure having a plurality of second communication holes provided in the frame body and communicated with the plurality of first communication holes. A regulating valve is provided, and a first communication hole is opened on the first surface of the frame body on the side of the pressure regulating valve, and a second communication hole is provided on the second surface of the pressure regulating valve on the side of the frame body. The holes are open, and the opening of the second communication hole on the second surface does not overlap with the opening of the first communication hole on the first surface when viewed from the first direction intersecting the first surface.

In this power storage module, a frame provided so as to surround the electrode laminate has a first communication hole that communicates with the internal space in which the electrolytic solution is arranged. Further, the pressure adjusting valve provided in the frame body has a second communication hole communicated with the first communication hole. Therefore, when the pressure in the internal space rises, the gas in the internal space is discharged through the first communication hole and the second communication hole, and the pressure in the internal space is adjusted. In particular, in this power storage module, the opening of the second communication hole on the second surface of the pressure regulating valve becomes the opening of the first communication hole on the first surface when viewed from the direction intersecting the first surface of the frame. There is no duplication. In other words, the opening of the second communication hole is shifted with respect to the opening of the first communication hole. Therefore, when using (installing) this power storage module, the opening of the second communication hole of the pressure regulating valve located on the outer side can be arranged vertically above the opening of the first communication hole. Therefore, according to this power storage module, it is possible to reduce the discharge amount of the electrolytic solution.

In the power storage module according to the present invention, the frame has a plurality of first portions provided on the peripheral edge of each bipolar electrode, and a frame-shaped second portion provided so as to surround the electrode laminate and the first portion. A portion, the first portion comprises a first surface, the second portion has a plurality of third communication holes communicated with a plurality of first communication holes, and the pressure regulating valve in the second portion. A third communication hole may be opened on the third surface on the side, and the second communication hole may be communicated with the first communication hole via the third communication hole. In this way, the frame may be configured to include the first portion and the second portion.

In the power storage module according to the present invention, the opening of the second communication hole on the second surface does not have to overlap with the opening of the third communication hole on the third surface when viewed from the first direction. In this case, the opening of the second communication hole of the pressure regulating valve does not overlap with the opening of the first communication hole of the first portion and also with the opening of the third communication hole of the second portion located on the outer side. Therefore, the discharge amount of the electrolytic solution can be surely reduced.

In the power storage module according to the present invention, a first joining protrusion for joining the frame body and the pressure regulating valve to each other is formed on one of the second and third surfaces, and the first one is formed. The first end surface for joining one of the joining protrusions may be inclined with respect to one surface. In this case, the frame body and the pressure regulating valve are joined by using the inclined end face of the joining protrusion. As a result, the frame body and the pressure regulating valve are in a state of being inclined to each other. As a result, it is possible to easily and surely realize a configuration in which the opening of the second communication hole of the pressure regulating valve does not overlap with the opening of the first communication hole of the frame body.

In the power storage module according to the present invention, a second joining protrusion for joining the frame body and the pressure regulating valve to each other is provided on the other surface of the second surface and the third surface, and the second surface is provided. The second end face for joining of the joining protrusion is inclined with respect to the other surface, and the inclination angle of the first end face and the inclination angle of the second end face join the first end face and the second end face to each other. At this time, the angle between the second surface and the third surface may be set to be larger than the inclination angle of the first end surface and the inclination angle of the second end surface. In this case, the frame body and the pressure control valve are joined by using the inclined end faces of the joining protrusions provided on both the frame body and the pressure control valve. Therefore, the angle between the frame and the pressure regulating valve (the angle between the third surface and the second surface) can be distributed to the inclination angle of the end surface of each of the joining protrusions. Therefore, when a certain angle is generated between the frame and the pressure regulating valve, the inclination angle of the end face of each of the joining protrusions can be made relatively small. As a result, it is possible to suppress an increase in the amount of protrusion of the joining protrusion and to form the joining protrusion with high accuracy by, for example, injection molding.

The method for manufacturing a power storage module according to the present invention surrounds an electrode laminate including a plurality of bipolar electrodes laminated to each other, an electrolytic solution arranged in a plurality of internal spaces provided in the electrode laminate, and an electrode laminate. A first step of preparing a module main body having a frame body having a plurality of first communication holes and having a plurality of first communication holes communicated with each of a plurality of internal spaces, and a pressure adjusting valve having a plurality of second communication holes. After the second step and the first step and the second step to be prepared, the third step of joining the pressure adjusting valve to the frame so that each of the first communication hole and the second communication hole communicate with each other. And, on at least one of the frame and the pressure regulating valve, a joining protrusion for connecting the frame and the pressure regulating valve to each other is formed, and in the third step, the joining protrusion is formed. The frame and the pressure regulating valve are joined to each other so that the opening of the second communication hole in the pressure regulating valve is located above the opening of the first communication hole in the frame and does not overlap with each other by using the inclined end face of the pressure regulating valve. ..

According to this manufacturing method, as described above, it is possible to manufacture a power storage module capable of reducing the amount of electrolytic solution discharged. In particular, in this manufacturing method, when joining the pressure regulating valve to the frame, the inclined end face of the joining protrusion provided on at least one of the frame and the pressure regulating valve is used. Therefore, it is possible to easily and surely realize a configuration in which the opening of the second communication hole of the pressure regulating valve does not overlap with the opening of the first communication hole of the frame body.

The power storage module according to the present invention is arranged so as to surround an electrode laminate including a plurality of bipolar electrodes laminated to each other, an electrolytic solution arranged in a plurality of internal spaces provided in the electrode laminate, and an electrode laminate. A frame body having a plurality of first communication holes communicated with each of the plurality of internal spaces, and a pressure having a plurality of second communication holes provided in the frame body and communicated with the plurality of first communication holes. A regulating valve is provided, and a first communication hole is opened on the first surface of the frame body on the side of the pressure regulating valve, and a second communication hole is provided on the second surface of the pressure regulating valve on the side of the frame body. The holes are open, and the opening of the second communication hole on the second surface does not overlap with the position of the liquid surface of the electrolytic solution on the first surface when viewed from the first direction intersecting the first surface.

In this power storage module, a frame provided so as to surround the electrode laminate has a first communication hole that communicates with the internal space in which the electrolytic solution is arranged. Further, the pressure adjusting valve provided in the frame body has a second communication hole communicated with the first communication hole. Therefore, when the pressure in the internal space rises, the gas in the internal space is discharged through the first communication hole and the second communication hole, and the pressure in the internal space is adjusted. In particular, in this power storage module, the opening of the second communication hole on the second surface of the pressure regulating valve is the position of the liquid level of the electrolytic solution on the first surface when viewed from the direction intersecting the first surface of the frame. Does not overlap with. Therefore, when using (installing) this power storage module, the opening of the second communication hole of the pressure control valve located on the outer side is vertically above the liquid level of the electrolytic solution on the first surface of the frame. Can be placed. Therefore, according to this power storage module, it is possible to reduce the discharge amount of the electrolytic solution.

According to the present invention, it is possible to provide a power storage module capable of reducing the amount of electrolytic solution discharged, and a method for manufacturing the power storage module.

FIG. 1 is a schematic cross-sectional view showing a power storage device including a battery module according to an embodiment. FIG. 3 is a schematic cross-sectional view of the power storage module shown in FIG. It is a schematic perspective view of the power storage module shown in FIG. FIG. 3 is an exploded perspective view (including a partial cross section) showing a part of the power storage module shown in FIGS. 1 to 3. It is an enlarged view of the cross-sectional portion of FIG. It is a figure which shows one process of the power storage module manufacturing method which concerns on one Embodiment. It is a figure which shows one process of the power storage module manufacturing method which concerns on one Embodiment. It is a figure which shows one process of the power storage module manufacturing method which concerns on one Embodiment.

Hereinafter, one embodiment will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals may be used for the same or equivalent elements, and duplicate description may be omitted. Further, in each figure, an orthogonal coordinate system defined by the X-axis, the Y-axis, and the Z-axis may be shown.

FIG. 1 is a schematic cross-sectional view showing a power storage device including a battery module according to an embodiment. In FIG. 1, the power storage device 1 is used as a battery for a vehicle such as a forklift, a hybrid vehicle, or an electric vehicle. The power storage device 1 includes a plurality of (three in this case) power storage modules 2. The power storage module 2 is, for example, a secondary battery such as a nickel hydrogen secondary battery or a lithium ion secondary battery, or an electric double layer capacitor. In the following description, a nickel-metal hydride secondary battery will be illustrated.

The plurality of power storage modules 2 are laminated via a metal conductive plate 3. The conductive plate 3 is also arranged on the outside of the power storage module 2 located at both ends in the stacking direction (here, the Z-axis direction). The power storage module 2 and the conductive plate 3 have, for example, a rectangular shape (rectangular shape in a plan view) when viewed from the stacking direction. The conductive plate 3 is electrically connected to the adjacent power storage modules 2. As a result, the plurality of power storage modules 2 are connected in series in the stacking direction.

A positive electrode terminal 4 is connected to a conductive plate 3 located at one end (here, the lower end) in the stacking direction. The negative electrode terminal 5 is connected to the conductive plate 3 located at the other end (here, the upper end) in the stacking direction. The positive electrode terminal 4 and the negative electrode terminal 5 extend in a direction (here, the X-axis direction) intersecting (orthogonal) in the stacking direction. By providing such a positive electrode terminal 4 and a negative electrode terminal 5, it is possible to charge and discharge the power storage device 1.

The conductive plate 3 can also function as a heat sink for releasing the heat generated in the power storage module 2. The conductive plate 3 is provided with a plurality of voids 3a extending in a direction (here, the Y-axis direction) that intersects (orthogonally) the stacking direction and the extending direction of the positive electrode terminal 4 and the negative electrode terminal 5. When a refrigerant such as air passes through these voids 3a, the heat from the power storage module 2 can be efficiently released to the outside.

Further, the power storage device 1 includes a restraint unit 6 that restrains the power storage module 2 and the conductive plate 3 in the stacking direction. The restraint unit 6 has a pair of restraint plates 7 that sandwich the power storage module 2 and the conductive plate 3 in the stacking direction, and a plurality of sets of bolts 8 and nuts 9 that fasten the restraint plates 7 to each other.

The restraint plate 7 is made of a metal such as iron. An insulating film 10 such as a resin film is arranged between each restraint plate 7 and the conductive plate 3. The restraint plate 7 and the insulating film 10 have, for example, a rectangular shape in a plan view. With the shaft portion 8a of the bolt 8 inserted through the insertion hole 7a provided in each restraint plate 7, the nut 9 is screwed into the tip portion of the shaft portion 8a, whereby the power storage module 2, the conductive plate 3, and the insulating film are screwed. A restraining load in the stacking direction is applied to 10.

FIG. 2 is a schematic cross-sectional view of the power storage module shown in FIG. FIG. 3 is a schematic perspective view of the power storage module shown in FIG. In FIGS. 2 and 3, the power storage module 2 has a structure (plural cell structure) in which a plurality of cells (for example, 24 cells) are laminated. The power storage module 2 includes a module main body 11 and a plurality of (here, four) pressure adjusting valves 12 attached to one side surface of the module main body 11.

The module main body 11 has an electrode laminate 15 including a plurality of bipolar electrodes (plural electrodes) 13 laminated to each other. As an example, the stacking direction of the bipolar electrode 13 coincides with the stacking direction of the power storage module 2. The bipolar electrodes 13 are laminated via the separator 14. That is, the electrode laminate 15 includes a plurality of separators 14 alternately laminated with the bipolar electrode 13. Further, the module main body 11 has a frame body 16 arranged so as to surround the electrode laminated body 15.

The bipolar electrode 13 and the separator 14 have, for example, a rectangular shape in a plan view. The separator 14 is arranged between the bipolar electrodes 13 adjacent to each other in the stacking direction. The bipolar electrode 13 includes an electrode plate 17 which is a current collector, a positive electrode 18 formed on the upper surface 17a (one surface) of the electrode plate 17, and a negative electrode 19 formed on the lower surface 17b (the other surface) of the electrode plate 17. And have. The electrode plate 17 is made of metal and is made of, for example, nickel or a nickel-plated steel plate. The electrode plate 17 is a rectangular metal leaf made of, for example, nickel.

The positive electrode 18 of the bipolar electrode 13 faces the negative electrode 19 of one of the bipolar electrodes 13 adjacent to each other in the stacking direction with the separator 14 interposed therebetween. The negative electrode 19 of the bipolar electrode 13 faces the positive electrode 18 of the other bipolar electrode 13 adjacent to each other in the stacking direction with the separator 14 interposed therebetween.

A positive electrode side terminal electrode (electrode) 20 is arranged on the lowermost layer of the electrode laminate 15. The positive electrode side terminal electrode 20 has an electrode plate 17 and a positive electrode 18 formed on the upper surface 17a of the electrode plate 17. A negative electrode side terminal electrode (electrode) 21 is arranged on the uppermost layer of the electrode laminate 15. The negative electrode side terminal electrode 21 has an electrode plate 17 and a negative electrode 19 formed on the lower surface 17b of the electrode plate 17. The positive electrode 18 of the positive electrode side terminal electrode 20 faces the negative electrode 19 of the lowermost bipolar electrode 13 with the separator 14 interposed therebetween. The negative electrode 19 of the negative electrode side terminal electrode 21 faces the positive electrode 18 of the uppermost bipolar electrode 13 with the separator 14 interposed therebetween. The electrode plates 17 of the positive electrode side terminal electrode 20 and the negative electrode side terminal electrode 21 are connected to the conductive plates 3 (see FIG. 1) adjacent to each other in the stacking direction.

The positive electrode 18 is formed by applying a positive electrode active material to one surface of the electrode plate 17. As the positive electrode active material, for example, nickel hydroxide coated with a cobalt (Co) oxide is used. The negative electrode 19 is formed by applying a negative electrode active material to the other surface of the electrode plate 17. As the negative electrode active material, for example, a hydrogen storage alloy is used. The peripheral edge portion 17c of the electrode plate 17 is an uncoated region in which the positive electrode active material and the negative electrode active material are not coated.

The separator 14 is arranged between the positive electrode 18 and the negative electrode 19, and separates the positive electrode 18 and the negative electrode 19. The separator 14 is smaller than the electrode plate 17 and larger than the positive electrode 18 and the negative electrode 19 when viewed from the stacking direction. The separator 14 is formed, for example, in the form of a sheet. The separator 14 is formed of a porous film made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP), or a non-woven fabric or woven fabric made of PE, PP, methyl cellulose or the like. Further, the separator 14 may be reinforced with a vinylidene fluoride resin compound or the like. The shape of the separator 14 is not particularly limited to a sheet shape, but may be a bag shape.

The frame body 16 is arranged around the electrode laminated body 15, and has a plurality of primary seal portions (plural first portions) 22 provided on the peripheral edge portion 17c of each electrode plate 17, and the electrode laminated body 15 and the primary seal portion. It has a secondary seal portion (second portion) 23 provided around the primary seal portion 22 so as to surround the 22.

Each primary seal portion 22 is arranged for each electrode plate 17 along the stacking direction. The primary seal portion 22 is formed in a frame shape. The primary seal portion 22 is joined to the peripheral edge portion 17c of the electrode plate 17 by, for example, heat welding.

An internal space V formed by the electrode plates 17 and the primary sealing portion 22 is provided between the electrode plates 17 adjacent to each other in the stacking direction. Therefore, the electrode laminate 15 is provided with a plurality of internal spaces V. An alkaline electrolytic solution is arranged (injected) in the internal space V including the inside of the separator 14. As the alkaline electrolytic solution, for example, an alkaline solution containing an aqueous solution of potassium hydroxide or the like is used. The primary seal portion 22 seals the internal space V. Each cell of the power storage module 2 is composed of two electrode plates 17, a positive electrode 18, a negative electrode 19, a separator 14, and a primary seal portion 22, and has an internal space V.

The secondary seal portion 23 has a square tubular shape. The secondary seal portion 23 further seals the internal space V. The secondary seal portion 23 is joined to the primary seal portion 22. The secondary seal portion 23 is formed by, for example, injection molding or the like. The primary seal portion 22 and the secondary seal portion 23 are formed of a resin such as polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE).

Here, FIG. 4 is an exploded perspective view (including a partial cross section) showing a part of the power storage module. FIG. 5 is an enlarged view of a cross-sectional portion of FIG. As shown in FIGS. 3 to 5, one wall portion 16a constituting the frame body 16 is provided with a plurality of (here, four) mounting regions 24 to which the pressure adjusting valve 12 is mounted. Each of the mounting areas 24 of the primary seal portion 22 is provided with a plurality of (six in this case) communication holes 25 (a plurality of first communication holes). The communication holes 25 are arranged in two rows and three stages (two rows in the Y-axis direction and three stages in the Z-axis direction) in the mounting area 24. Therefore, the communication holes 25 are arranged in eight rows and three stages in the wall portion 16a. Each of the communication holes 25 communicates with each of the internal spaces V of different cells.

That is, the frame body 16 has a plurality of communication holes 25 communicated with each of the plurality of internal spaces V. The communication hole 25 is open to the internal space V and the surface (first surface) 22s on the pressure adjusting valve 12 side of the frame body 16. The surface 22s is a surface of the primary seal portion 22 on the pressure adjusting valve 12 side (secondary seal portion 23 side).

Each of the attachment regions 24 of the secondary seal portion 23 is provided with a plurality of (six in this case) communication holes 26 (several third communication holes) that communicate with the communication holes 25. That is, the secondary seal portion 23 has a plurality of communication holes 26 communicated with the plurality of communication holes 25. The communication hole 26 is open to the surface 23r on the internal space V side (primary seal portion 22 side) of the secondary seal portion 23 and the surface (third surface) 23s on the pressure adjusting valve 12 side. The surface 23s is an outer surface of the frame body 16. The communication hole 26 is formed in a tapered shape so as to gradually widen from the surface 23r toward the surface 23s. The communication holes 26 are arranged in two rows and three stages in the mounting area 24.

The communication holes 25 and 26 function as liquid injection holes for injecting the electrolytic solution into the internal space V. Further, the communication holes 25 and 26 serve as a flow path through which the gas generated in the internal space V flows after the electrolytic solution is injected.

A bonding protrusion (first bonding protrusion) 27 is provided on the surface 23s of the secondary sealing portion 23. The joining protrusion 27 is used for joining the module main body 11 and the pressure regulating valve 12. Further, the bonding projection 27 forms a plurality of (six in this case) flow paths 28 through which gas from each internal space V flows in cooperation with the communication holes 26. The flow paths 28 are arranged in two rows and three stages in each of the mounting regions 24. The flow path 28 has a rectangular shape with a cross section cut in a direction perpendicular to the X-axis direction. The flow path 28 in one row is displaced in the stacking direction (Z-axis direction) with respect to the flow path 28 in the other row.

The joining protrusion 27 has a frame portion 29 forming the flow path 28 in one row and a frame portion 30 forming the flow path 28 in the other row. The frame portions 29 and 30 have the same shape and are offset from each other in the Z-axis direction. A gap extending in the Z-axis direction is formed between the frame portions 29 and 30.

The pressure regulating valve 12 has a case 33, a plurality of (six in this case) valve bodies 34, and a cover 35. The case 33 is made of a resin such as PP, PPS or modified PPE. The case 33 has a bottom wall portion 36. The bottom wall portion 36 (that is, the pressure regulating valve 12) has a plurality of (six in this case) communication holes penetrating from the surface (second surface) 36s on the frame body 16 side of the bottom wall portion 36 toward the cover 35 side. 37 (plurality of second communication holes) is provided. The surface 36s is an outer surface of the pressure regulating valve 12. These communication holes 37 communicate with each of the communication holes 25 via the communication holes 26. The communication hole 37 has a circular shape with a cross section cut in a direction perpendicular to the X-axis direction (see FIG. 5). The communication hole 37 opens inside the case 33 (accommodation recess 44a described later) and in the surface 36s.

A substantially frame-shaped joining protrusion (second joining protrusion) 38 is provided on the surface 36s. The joining protrusion 38 is used for joining the module main body 11 and the pressure regulating valve 12. Further, the bonding projection 38 forms a plurality of (six in this case) flow paths 39 through which gas from the internal space V flows. The frame body 16 and the pressure regulating valve 12 are joined by joining the joining protrusion 27 and the joining protrusion 38. The joining protrusion 38 has a shape and dimensions corresponding to the joining protrusion 27. Therefore, the flow path 39 has a rectangular shape with a cross section cut in a direction perpendicular to the X-axis direction. The flow path 39 in one row is displaced in the Z-axis direction with respect to the flow path 39 in the other row.

The joining protrusion 38 has a frame portion 40 forming a flow path 39 in one row and a frame portion 41 forming a flow path 39 in the other row. The frame portions 40 and 41 have the same shape and are offset from each other in the Z-axis direction. A gap extending in the Z-axis direction is formed between the frame portions 40 and 41.

The case 33 has an inner wall portion 44 that forms a plurality of (six in this case) accommodating recesses 44a for accommodating the valve body 34. The inner wall portion 44 is integrated with the bottom wall portion 36. The accommodating recess 44a has a circular shape with a cross section cut in a direction perpendicular to the X-axis direction. The accommodating recess 44a can communicate with the communication hole 37.

The valve body 34 is accommodated in the accommodating recess 44a so as to close the communication hole 37. The valve body 34 is a columnar member formed of an elastic body such as rubber. The valve body 34 opens and closes the communication hole 37. A gap G is provided between the outer surface of the valve body 34 and the inner wall surface of the inner wall portion 44 (see FIG. 6).

The cover 35 is a plate-shaped member that closes the opening of the case 33. The cover 35 is made of a resin such as PP, PPS or modified PPE. The cover 35 is joined to the open end face of the case 33 by heat welding. The cover 35 also functions as a pressing member that presses the plurality of valve bodies 34 against the bottom wall portion 36 of the case 33. A storage space S communicating with the storage recess 44a is provided between the inner wall portion 44 of the case 33 and the cover 35. Further, the cover 35 is provided with a plurality of (here, two) exhaust ports 45. The exhaust port 45 communicates with the accommodation space S.

In such a pressure adjusting valve 12, the communication hole 37 communicates with the internal space V of the module main body 11 through the communication hole 26 of the secondary seal portion 23 and the communication hole 25 of the primary seal portion 22. When the pressure in the internal space V is lower than the set pressure, the communication hole 37 is maintained in a closed state in which the communication hole 37 is closed by the valve body 34. When the pressure in the internal space V rises to exceed the set pressure, the valve body 34 is elastically deformed so as to be separated from the bottom wall portion 36, and the communication hole 37 is released from the closed state. As a result, the gas from the internal space V is discharged from the exhaust port 45 through the gap between the outer surface of the valve body 34 and the inner wall surface of the inner wall portion 44 and the accommodation space S.

Here, as described above, the communication hole 25 is opened in the surface 22s on the pressure adjusting valve 12 side of the frame body 16 (primary seal portion 22) (see FIG. 5). Further, a communication hole 37 is opened in the surface 36s on the frame body 16 side of the pressure adjusting valve 12 (bottom wall portion 36). The openings of the communication holes 37 and the communication holes 25 that communicate with each other do not overlap each other when viewed from the first direction (here, the X-axis direction) intersecting (orthogonal) with the surface 22s. That is, when viewed from the first direction, the opening 37h of the communication hole 37 in the surface 36s does not overlap with the opening 25h of the communication hole 25 (communication with the communication hole 37) in the surface 22s.

Further, as described above, the communication hole 26 is opened in the surface 23s on the pressure adjusting valve 12 side of the secondary seal portion 23. When viewed from the first direction, the openings of the communication holes 26 and the communication holes 25 that communicate with each other do not overlap each other. That is, when viewed from the first direction, the opening 37h of the communication hole 37 in the surface 36s does not overlap with the opening 26h of the communication hole 26 (communication with the communication hole 37) in the surface 23s.

Here, the fact that the openings do not overlap each other when viewed from the first direction means that the openings are shifted from each other when viewed from the first direction, and the outer edges thereof do not overlap each other. Here, when viewed from the first direction, the opening 37h and the opening 25h (and the opening 26h) are shifted from each other in the stacking direction (Z-axis direction) (the opening 37h is located vertically above the opening 25h). Yes). Further, the fact that the openings do not overlap each other when viewed from the first direction means that a region different from the openings is interposed between the openings when viewed from the first direction.

In the power storage module 2, it is possible to realize a configuration in which the openings 37h and the openings 25h and 26h described above do not overlap by any embodiment, but in the present embodiment, the frame 16 and the pressure regulating valve 12 are tilted. It is realized by being joined together. This point will be described more specifically. In the power storage module 2, as described above, the bonding projection 27 is formed on the surface 23s of the secondary seal portion 23, which is the outer surface of the frame body 16. The end surface (first end surface) 27s of the joining projection 27 is inclined with respect to the surface 23s with an inclination angle α. The end face 27a is an end face for joining with the pressure regulating valve 12 (joining protrusion 38).

Further, a joining protrusion 38 is formed on the surface 36s of the bottom wall portion 36 which is the outer surface of the pressure adjusting valve 12. The end surface (second end surface) 38a of the joining projection 38 is inclined with respect to the surface 36s with an inclination angle β. The end face 38a is an end face for joining with the frame body 16 (joining protrusion 27). The frame body 16 and the pressure regulating valve 12 are inclined and arranged by being joined to each other by using their inclined end faces 27a and 38a.

In particular, the inclination angle α of the end surface 27a and the inclination angle β of the end surface 38a are such that when the end surface 27a and the end surface 38a are joined to each other, the angle γ between the surface 23s and the surface 36s is the inclination angle α and the inclination angle β. It is set to be larger than each. Here, the angle γ is the sum of the value of the tilt angle α and the value of the tilt angle β. As a result, the frame body 16 and the pressure regulating valve 12 are tilted and joined, and a configuration in which the openings 37h and the openings 25h and 26h do not overlap can be realized.

Here, the relationship between the frame body 16 and the pressure regulating valve 12 may be defined by the opening and the liquid level of the electrolytic solution. For example, a communication hole in the surface 36s on the frame 16 side of the pressure regulating valve 12 (bottom wall portion 36) when viewed from the first direction intersecting the surface 22s on the pressure regulating valve 12 side in the frame 16 (primary seal portion 22). The opening 37h of 37 does not overlap with the position P1 of the liquid surface of the electrolytic solution R on the surface 22s. Further, when viewed from the first direction, the opening 37h of the communication hole 37 in the surface 36s does not overlap with the position P3 of the liquid surface of the electrolytic solution R in the surface 23s. Such a relationship can also be realized by using the joining protrusions 27 and 38 as described above as an example.

Subsequently, an example of a power storage module manufacturing method for manufacturing the power storage module 2 will be described. In this manufacturing method, first, a first step of preparing the module main body 11 and a second step of preparing the pressure regulating valve 12 are performed. The order of the first step and the second step is not limited. Subsequently, after the first step and the second step, the frame 16 is provided with the communication holes 25 and 26 on the module body 11 side and the communication holes 37 on the pressure control valve 12 side so as to communicate with each other. The third step of joining the pressure regulating valve 12 is performed.

In the third step, using the inclined end faces 27a and 38a of the joining protrusions 27 and 38, the opening 37h of the communication hole 37 in the pressure regulating valve 12 and the opening 25h and 26h of the communication holes 25 and 26 in the frame body 16 are used. The frame 16 and the pressure regulating valve 12 are joined to each other so as not to overlap with each other (or so that the opening 37h of the communication hole 37 does not overlap with the positions P1 and P3 of the liquid surface of the electrolytic solution R). More specifically, in the third step, as shown in FIG. 6, first, the module main body 11 and the pressure adjusting valve 12 are arranged so that the joining projections 27 and 38 face each other, and the module main body 11 is arranged. A hot plate 46 is arranged between the pressure regulating valve 12 and the pressure regulating valve 12.

Next, as shown in FIG. 7, the end faces 27a and 38a are melted by bringing the end faces 27a and 38a into contact with the hot plate 46. Then, as shown in FIG. 8, while the end faces 27a and 38a are melted, the joining protrusions 27 and the joining protrusions 38 are pressed against each other to weld the joining protrusions 27 and 38 to each other. As a result, the bonding projections 27 and 38 are joined to each other, and the pressure adjusting valve 12 is provided on the module main body 11 to obtain the power storage module 2.

As described above, in the power storage module 2, the frame body 16 has a communication hole 25 that communicates with the internal space V in which the electrolytic solution is arranged. Further, the pressure adjusting valve 12 provided in the frame body 16 has a communication hole 37 communicated with the communication hole 25. Therefore, when the pressure in the internal space V rises, the gas in the internal space V is discharged through the communication hole 25 and the communication hole 37, and the pressure in the internal space V is adjusted. In particular, in the power storage module 2, the opening 37h of the communication hole 37 in the surface 36s of the pressure regulating valve 12 overlaps with the opening 25h of the communication hole 25 in the surface 22s when viewed from the direction intersecting the surface 22s of the frame body 16. Not done. In other words, the opening 37h of the communication hole 37 is shifted with respect to the opening 25h of the communication hole 25. Therefore, when the power storage module 2 is used (installed), the opening 37h of the communication hole 37 of the pressure regulating valve 12 located on the outer side can be arranged vertically above the opening 25h of the communication hole 25. Therefore, according to the power storage module 2, the discharge amount of the electrolytic solution can be reduced.

Further, in the power storage module 2, the frame body 16 surrounds a plurality of primary seal portions 22 provided on the peripheral edge portions 17c of each electrode (bipolar electrode 13, etc.), the electrode laminate 15, and the primary seal portion 22. The frame-shaped secondary seal portion 23 provided in the above is included. The primary seal portion 22 includes a surface 22s. The secondary seal portion 23 has a plurality of communication holes 26 communicated with the plurality of communication holes 25. A communication hole 26 is opened in the surface 23s on the side of the pressure adjusting valve 12 in the secondary seal portion 23. The communication hole 37 is communicated with the communication hole 25 via the communication hole 26. In this way, the frame body 16 may be configured to include the primary seal portion 22 and the secondary seal portion 23.

Further, in the power storage module 2, the opening 37h of the communication hole 37 in the surface 36s does not overlap with the opening 26h of the communication hole 26 in the surface 23s when viewed from the first direction. Therefore, the opening 37h of the communication hole 37 of the pressure adjusting valve 12 is not only the opening 25h of the communication hole 25 of the primary seal portion 22 but also the opening 26h of the communication hole 26 of the secondary seal portion 23 located on the outer side. Not duplicate. Therefore, the discharge amount of the electrolytic solution can be surely reduced.

Further, in the power storage module 2, a joining projection 27 for joining the frame body 16 and the pressure regulating valve 12 to each other is formed on the surface 23s. The joining end surface 27a of the joining protrusion 27 is inclined with respect to the surface 23s. Therefore, the frame body 16 and the pressure adjusting valve 12 are joined by using the inclined end surface 27a of the joining protrusion 27. As a result, the frame body 16 and the pressure regulating valve 12 are in a state of being inclined to each other. As a result, it is possible to easily and surely realize a configuration in which the opening 37h of the communication hole 37 of the pressure adjusting valve 12 does not overlap with the opening 25h of the communication hole 25 of the frame body 16.

Further, in the power storage module 2, the surface 36s is provided with a joining protrusion 38 for joining the frame body 16 and the pressure regulating valve 12 to each other. The joining end surface 38a of the joining protrusion 38 is inclined with respect to the surface 36s. The inclination angle α of the end face 27a and the inclination angle β of the end surface 38a are such that when the end surface 27a and the end surface 38a are joined to each other, the angle γ between the surface 36s and the surface 23s is the inclination angle α and the inclination angle β. It is set to be larger than each.

In this case, the frame body 16 and the pressure control valve 12 are joined by using the inclined end faces 27a, 38a of the joining protrusions 27, 38 provided on both the frame body 16 and the pressure control valve 12. .. Therefore, the angle between the frame body 16 and the pressure regulating valve 12 can be distributed to the inclination angles α and β of the end faces 27a and 38a of the joining projections 27 and 38, respectively. Therefore, when a certain angle is generated between the frame body 16 and the pressure regulating valve 12, the respective inclination angles α and β can be made relatively small. As a result, it is possible to suppress an increase in the amount of protrusion of the joining protrusions 27 and 38, and to form the joining protrusions 27 and 38 with high accuracy by, for example, injection molding.

Further, according to the power storage module manufacturing method according to the present embodiment, as described above, the power storage module 2 capable of reducing the discharge amount of the electrolytic solution can be manufactured. In particular, in this manufacturing method, when the pressure regulating valve 12 is joined to the frame body 16, the inclined end face of the joining protrusion provided on at least one of the frame body 16 and the pressure regulating valve 12 is used. Therefore, it is possible to easily and surely realize a configuration in which the opening 37h of the communication hole 37 of the pressure adjusting valve 12 does not overlap with the openings 25h and 26h of the communication holes 25 and 26 of the frame body 16.

In the power storage module 2, the frame body 16 has a communication hole 25 that communicates with the internal space V in which the electrolytic solution R is arranged. Further, the pressure adjusting valve 12 provided in the frame body 16 has a communication hole 37 communicated with the communication hole 25. Therefore, when the pressure in the internal space V rises, the gas in the internal space V is discharged through the communication hole 25 and the communication hole 37, and the pressure in the internal space V is adjusted. In particular, in the power storage module 2, the opening 37h of the communication hole 37 in the surface 36s of the pressure regulating valve 12 is the position of the liquid surface of the electrolytic solution R on the surface 22s when viewed from the direction intersecting the surface 22s of the frame body 16. It does not overlap with P1. Therefore, when the power storage module 2 is used (installed), the opening 37h of the communication hole 37 of the pressure regulating valve 12 located on the outer side is more vertical than the liquid level of the electrolytic solution R on the surface 22s of the frame body 16. Can be placed above. Therefore, according to the power storage module 2, the discharge amount of the electrolytic solution R can be reduced.

The above-described embodiment describes one embodiment of the present invention. Therefore, the present invention is not limited to the above-mentioned power storage module 2 and the manufacturing method thereof, and can be arbitrarily modified.

For example, in the above embodiment, both the secondary seal portion 23 and the pressure regulating valve 12 are provided with a joining protrusion having an inclined end face. However, a joining protrusion having an inclined end face may be provided on one of the surface 23s of the secondary seal portion 23 and the surface 36s of the pressure regulating valve 12. That is, it is not necessary to provide a joining protrusion on the other of the surface 23s of the secondary seal portion 23 and the surface 36s of the pressure regulating valve 12, or the end surface of the joining protrusion although the joining protrusion is provided. Does not have to be tilted.

Further, in the above embodiment, the inclination of the end faces 27a, 38a of the joining protrusions 27, 38 is used to incline the frame 16 (that is, the module body 11) and the pressure adjusting valve 12, and the opening 37h. Explained the mode in which the openings do not overlap with the openings 25h and 26h. However, for example, the opening 37h may not overlap with the openings 25h and 26h by forming the joining projection 38 so that the flow path 39 bends while the end face 27a and the end face 38a are parallel to each other. Further, depending on another configuration, the opening 37h may not overlap with the openings 25h and 26h.

The above embodiments will be described below.

[Appendix 1]
An electrode laminate containing a plurality of bipolar electrodes laminated to each other,
Electrolyte liquids arranged in a plurality of internal spaces provided in the electrode laminate and
A frame body arranged so as to surround the electrode laminate and having a plurality of first communication holes communicated with each of the plurality of internal spaces.
A pressure regulating valve provided in the frame body and having a plurality of second communication holes communicated with the plurality of first communication holes, respectively.
Equipped with
The first communication hole is opened on the first surface of the frame on the side of the pressure regulating valve.
The second communication hole is opened on the second surface of the pressure regulating valve on the side of the frame.
The opening of the second communication hole in the second surface does not overlap with the position of the liquid surface of the electrolytic solution in the first surface when viewed from the first direction intersecting the first surface.
Power storage module.
[Appendix 2]
The frame includes a plurality of first portions provided on the peripheral edge of each of the bipolar electrodes, and a frame-shaped second portion provided so as to surround the electrode laminate and the first portion. ,
The first portion includes the first surface.
The second portion has a plurality of third communication holes communicated with the plurality of first communication holes.
The third communication hole is opened on the third surface of the second portion on the side of the pressure regulating valve.
The second communication hole is communicated with the first communication hole through the third communication hole.
The power storage module according to Appendix 1.
[Appendix 3]
When viewed from the first direction, the opening of the second communication hole on the second surface does not overlap with the position of the liquid level of the electrolytic solution on the third surface.
The power storage module according to Appendix 2.
[Appendix 4]
On one of the second surface and the third surface, a first joining protrusion for joining the frame body and the pressure regulating valve to each other is formed.
The first end surface for joining of the first joining protrusion is inclined with respect to the one surface.
The power storage module according to Appendix 2 or 3.
[Appendix 5]
On the other surface of the second surface and the third surface, a second joining protrusion for joining the frame body and the pressure regulating valve to each other is provided.
The second end surface for joining of the second joining protrusion is inclined with respect to the other surface.
The inclination angle of the first end surface and the inclination angle of the second end surface are such that when the first end surface and the second end surface are joined to each other, the angle between the second surface and the third surface is the same. It is set to be larger than each of the inclination angle of the first end surface and the inclination angle of the second end surface.
The power storage module according to Appendix 4.
[Appendix 6]
An electrode laminate including a plurality of bipolar electrodes laminated to each other, an electrolytic solution arranged in a plurality of internal spaces provided in the electrode laminate, and the plurality of interiors arranged so as to surround the electrode laminate. A first step of preparing a frame body having a plurality of first communication holes communicated with each of the spaces, and a module body having the first communication holes.
The second step of preparing a pressure regulating valve having a plurality of second communication holes, and
After the first step and the second step, a third step of joining the pressure regulating valve to the frame body so that each of the first communication holes and each of the second communication holes communicate with each other. ,
Equipped with
At least one of the frame and the pressure regulating valve is formed with a joining protrusion for connecting the frame and the pressure regulating valve to each other.
In the third step, the inclined end face of the joining protrusion is used so that the opening of the second communication hole in the pressure regulating valve is arranged above the position of the liquid level of the electrolytic solution and does not overlap. Joining the frame and the pressure regulating valve to each other,
Energy storage module manufacturing method.

2 ... power storage module, 12 ... pressure control valve, 13 ... bipolar electrode (electrode), 16 ... frame, 22 ... primary seal (first part), 22s ... surface (first surface), 23 ... secondary seal (Second part), 23s ... surface (third surface), 25 ... communication hole (first communication hole), 25h, 26h, 37h ... opening, 26 ... communication hole (third communication hole), 27 ... bonding protrusion (1st joining protrusion), 27a ... End face (1st end face), 36s ... Face (2nd surface), 37 ... Communication hole (2nd communication hole), 38 ... Joining protrusion (2nd joining protrusion), 38a ... End face (second end face), α, β ... Tilt angle.

Claims (7)

An electrode laminate containing a plurality of bipolar electrodes laminated to each other,
Electrolyte liquids arranged in a plurality of internal spaces provided in the electrode laminate and
A frame body arranged so as to surround the electrode laminate and having a plurality of first communication holes communicated with each of the plurality of internal spaces.
A pressure regulating valve provided in the frame body and having a plurality of second communication holes communicated with the plurality of first communication holes, respectively.
Equipped with
The first communication hole is opened on the first surface of the frame on the side of the pressure regulating valve.
The second communication hole is opened on the second surface of the pressure regulating valve on the side of the frame.
The opening of the second communication hole on the second surface is arranged vertically above the opening of the first communication hole on the first surface.
The opening of the second communication hole in the second surface does not overlap with the opening of the first communication hole in the first surface when viewed from the first direction intersecting the first surface.
Power storage module. The frame includes a plurality of first portions provided on the peripheral edge of each of the bipolar electrodes, and a frame-shaped second portion provided so as to surround the electrode laminate and the first portion. ,
The first portion includes the first surface.
The second portion has a plurality of third communication holes communicated with the plurality of first communication holes.
The third communication hole is opened on the third surface of the second portion on the side of the pressure regulating valve.
The second communication hole is communicated with the first communication hole through the third communication hole.
The power storage module according to claim 1. The opening of the second communication hole on the second surface is arranged vertically above the opening of the third communication hole on the third surface.
Seen from the first direction, the opening of the second communication hole on the second surface does not overlap with the opening of the third communication hole on the third surface.
The power storage module according to claim 2. On one of the second surface and the third surface, a first joining protrusion for joining the frame body and the pressure regulating valve to each other is formed.
The first end surface for joining of the first joining protrusion is inclined with respect to the one surface.
The power storage module according to claim 2 or 3. On the other surface of the second surface and the third surface, a second joining protrusion for joining the frame body and the pressure regulating valve to each other is provided.
The second end surface for joining of the second joining protrusion is inclined with respect to the other surface.
The inclination angle of the first end surface and the inclination angle of the second end surface are such that when the first end surface and the second end surface are joined to each other, the angle between the second surface and the third surface is the same. It is set to be larger than each of the inclination angle of the first end surface and the inclination angle of the second end surface.
The power storage module according to claim 4. An electrode laminate including a plurality of bipolar electrodes laminated to each other, an electrolytic solution arranged in a plurality of internal spaces provided in the electrode laminate, and the plurality of interiors arranged so as to surround the electrode laminate. A first step of preparing a frame body having a plurality of first communication holes communicated with each of the spaces, and a module body having the first communication holes.
The second step of preparing a pressure regulating valve having a plurality of second communication holes, and
After the first step and the second step, a third step of joining the pressure regulating valve to the frame body so that each of the first communication holes and each of the second communication holes communicate with each other. ,
Equipped with
At least one of the frame and the pressure regulating valve is formed with a joining protrusion for connecting the frame and the pressure regulating valve to each other.
In the third step, the opening of the second communication hole in the pressure regulating valve is arranged above the opening of the first communication hole in the frame body and overlaps with each other by using the inclined end surface of the joining protrusion. The frame and the pressure regulating valve are joined to each other so as not to prevent.
Energy storage module manufacturing method. An electrode laminate containing a plurality of bipolar electrodes laminated to each other,
Electrolyte liquids arranged in a plurality of internal spaces provided in the electrode laminate and
A frame body arranged so as to surround the electrode laminate and having a plurality of first communication holes communicated with each of the plurality of internal spaces.
A pressure regulating valve provided in the frame body and having a plurality of second communication holes communicated with the plurality of first communication holes, respectively.
Equipped with
The first communication hole is opened on the first surface of the frame on the side of the pressure regulating valve.
The second communication hole is opened on the second surface of the pressure regulating valve on the side of the frame.
The opening of the second communication hole on the second surface is arranged vertically above the position of the liquid surface of the electrolytic solution on the first surface.
The opening of the second communication hole in the second surface does not overlap with the position of the liquid surface of the electrolytic solution in the first surface when viewed from the first direction intersecting the first surface.
Power storage module.

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