JP2021009794A - Power storage module and power storage device - Google Patents

Abstract

To provide a power storage module and a power storage device, capable of inhibiting electrolytic solution discharged from an exhaust port of a pressure regulating valve from flowing through a surface of the pressure regulating valve in a direction from the exhaust port to the inside of the pressure regulating valve.SOLUTION: A power storage module 2 comprises: a module body 11 including an electrode laminate 15 and a frame body 16; and a pressure regulating valve 12. The pressure regulating valve 12 comprises a housing 50 and a valve body 30. On a side surface 31s is provided an exhaust port 41 for discharging gas generated in an internal space V. The pressure regulating valve 12 comprises an inclined part 31b located below the exhaust port 41 in the gravity direction. The inclined part 31b has an inclined surface 31t that extends along a center axis direction H1a of the exhaust port 41 and is inclined downward in the gravity direction from its base end side connected to the housing 50 to its tip.SELECTED DRAWING: Figure 5

Description

One aspect of the present invention relates to a power storage module and a power storage device.

A power supply device in which isolation members are arranged between battery modules arranged vertically is known (Patent Document 1). A discharge port is formed on the bottom plate of the isolation member. In this power supply device, the electrolytic solution discharged from the safety valve of the battery module is received by the bottom plate of the isolation member and discharged from the discharge port.

Japanese Unexamined Patent Publication No. 2006-331957

By the way, for example, when a power supply device is mounted on an automobile, the power supply device may be tilted with respect to a horizontal plane. In the above power supply device, since there is a gap between the battery module and the isolation member, when the power supply device is tilted so that the discharge port moves upward, the electrolyte discharged from the safety valve (pressure regulating valve) is discharged from the battery module. It may travel along the surface and wrap around to the underside of the battery module.

Further, in the above battery module, a plate-shaped output terminal is attached below the safety valve. Since the output terminals extend parallel to the horizontal plane, if the power supply device is tilted as described above, the electrolytic solution may travel along the lower surface of the output terminals and wrap around to the lower surface of the battery module.

In this way, when the power storage module is tilted so that the exhaust port of the pressure regulating valve moves upward, the electrolytic solution discharged from the exhaust port of the pressure regulating valve travels along the surface of the pressure regulating valve and adjusts the pressure from the exhaust port. It may flow toward the inside of the valve.

One aspect of the present invention is a power storage module and a power storage device capable of suppressing the electrolytic solution discharged from the exhaust port of the pressure control valve from flowing in the direction from the exhaust port toward the inside of the pressure control valve along the surface of the pressure control valve. The purpose is to provide.

The power storage module according to one aspect of the present invention communicates with an electrode laminate having a plurality of stacked electrodes and an internal space formed between the plurality of adjacent electrodes, which is arranged so as to surround the electrode laminate. A module body having a frame body having a first communication hole and a pressure adjusting valve attached to the module body are provided, and an electrolytic solution is housed in the internal space. A housing having a second communication hole communicated with the first communication hole, and a valve body housed in the housing and closing the second communication hole, the housing is formed with the second communication hole. It has a first surface, a second surface arranged on the side opposite to the first surface with the valve body interposed therebetween, and a third surface connecting the first surface and the second surface. The second surface or the third surface is provided with an exhaust port for discharging the gas generated in the internal space, passing through the first communication hole and the second communication hole, and flowing into the housing. The pressure regulating valve is connected to the housing and includes an inclined portion located below the exhaust port in the gravity direction, and the inclined portion extends along the central axis direction of the exhaust port and is attached to the housing. It has an inclined surface that inclines downward in the direction of gravity from the connected base end side to the tip end side.

In the power storage module, when the gas generated in the internal space is discharged from the exhaust port, the electrolytic solution may be discharged together. In this case, the electrolytic solution discharged from the exhaust port flows downward along the surface provided with the exhaust port, and then flows downward along the inclined inclined surface. Here, the inclined surface extends along the central axis direction of the exhaust port and is inclined downward in the direction of gravity from the proximal end side connected to the housing to the distal end. Therefore, even if the power storage module is tilted by an angle smaller than the angle (acute angle) θ formed by the central axis direction and the tilting direction of the tilted surface so that the exhaust port moves upward, the lower end of the tilted surface is the tilted surface. It is located below the top edge. Therefore, in the power storage module, it is possible to prevent the electrolytic solution discharged from the exhaust port of the pressure regulating valve from flowing in the direction from the exhaust port toward the inside of the pressure regulating valve along the surface of the pressure regulating valve.

In the width direction viewed from the central axis direction, the length of the inclined surface may be longer than the length of the exhaust port. In this case, all or most of the electrolytic solution discharged from the exhaust port flows on the inclined surface.

In the width direction viewed from the central axis direction, the inclined surface may be inclined downward from both ends of the inclined surface toward the center. In this case, it is possible to suppress the flow of the electrolytic solution from both ends of the inclined surface to the outside in the width direction.

The power storage device according to one aspect of the present invention is a power storage device including a first power storage module and a second power storage module stacked on the first power storage module, and the second power storage module is the power storage module. The lower end of the inclined portion is overlapped with the first power storage module when viewed from the central axis direction.

In the power storage device, it is possible to prevent the electrolytic solution that has fallen from the lower end of the inclined surface from flowing between the first power storage module and the second power storage module.

According to one aspect of the present invention, a power storage module capable of suppressing the electrolytic solution discharged from the exhaust port of the pressure regulating valve from flowing in the direction from the exhaust port toward the inside of the pressure regulating valve along the surface of the pressure regulating valve. A power storage device may be provided.

It is schematic cross-sectional view which shows an example of the power storage device including the power storage module which concerns on this embodiment. It is the schematic sectional drawing which shows an example of the internal structure of the power storage module. It is a schematic perspective view of a power storage module. It is an exploded perspective view (including a partial sectional view) which shows a part of a power storage module. It is a side view which shows a part of the power storage device seen from the Y-axis direction. It is a figure which shows the pressure adjustment valve seen from the X-axis direction. It is sectional drawing which shows the inclined part of the pressure adjustment valve which concerns on a modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and duplicate description is omitted. In the figure, the XYZ Cartesian coordinate system is shown as needed.

FIG. 1 is a schematic cross-sectional view showing an example of a power storage device including a power storage module according to the present embodiment. The power storage device 1 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 includes a module stack 4 including a plurality of stacked power storage modules 2 and a restraint member 3 that applies a restraining load to the module stack 4 in the stacking direction D of the module stack 4. ..

The module laminate 4 includes a plurality of (here, four) power storage modules 2 and a plurality of (here, three) conductive plates 5. The power storage module 2 is a bipolar battery and has a rectangular shape when viewed from the stacking direction D. 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 hydrogen secondary battery will be illustrated.

The power storage modules 2 adjacent to each other in the stacking direction D are electrically connected in series via a conductive plate 5. A conductive plate P electrically connected to the power storage module 2 and an insulating plate F are sequentially laminated at the laminated end of the module laminated body 4 in the stacking direction D. A positive electrode terminal 6 is connected to one conductive plate P, and a negative electrode terminal 7 is connected to the other conductive plate P. The positive electrode terminal 6 and the negative electrode terminal 7 are drawn out from the edge of the conductive plate P, for example, in a direction intersecting the stacking direction D. The positive electrode terminal 6 and the negative electrode terminal 7 charge and discharge the power storage device 1.

Inside the conductive plate 5 arranged between the power storage modules 2, a plurality of flow paths 5a through which a cooling medium such as air is circulated are provided. The flow path 5a extends along a direction that intersects (orthogonally), for example, the stacking direction D and the pull-out direction of the positive electrode terminal 6 and the negative electrode terminal 7. The conductive plate 5 has a function as a connecting member that electrically connects the power storage modules 2 to each other. Further, the conductive plate 5 also has a function as a heat radiating plate that dissipates heat generated by the power storage module 2 by circulating a cooling medium through these flow paths 5a. In the example of FIG. 1, the area of the conductive plate 5 seen from the stacking direction D is smaller than the area of the power storage module 2, but from the viewpoint of improving heat dissipation, the area of the conductive plate 5 is the power storage module 2. It may be the same as the area of, and may be larger than the area of the power storage module 2.

The restraint member 3 is composed of a pair of end plates 8 that sandwich the module laminate 4 in the stacking direction D, and fastening bolts 9 and nuts 10 that fasten the end plates 8 to each other. The end plate 8 is a rectangular metal plate having an area one size larger than the areas of the power storage module 2, the conductive plate 5, and the conductive plate P as viewed from the stacking direction D. Since an insulating plate F having electrical insulation is provided between each end plate 8 and the conductive plate P, the insulating plate F insulates between the end plate 8 and the conductive plate P. ..

An insertion hole 8a is provided at the edge of the end plate 8 at a position outside the module laminate 4. The fastening bolt 9 is passed from the insertion hole 8a of one end plate 8 toward the insertion hole 8a of the other end plate 8. A nut 10 is screwed into the tip portion of the fastening bolt 9 protruding from the insertion hole 8a of the other end plate 8. As a result, the power storage module 2, the conductive plate 5, and the conductive plate P are sandwiched by the end plates 8 and unitized as the module laminate 4. Further, a restraining load is applied to the module laminated body 4 in the stacking direction D.

Next, the configuration of the power storage module 2 will be described in detail. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module. FIG. 3 is a schematic perspective view of the power storage module. 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 in the stacking direction D. The power storage module 2 includes a module main body 11 and a plurality of (here, four) pressure regulating valves 12 attached to the module main body 11. The module main body 11 includes an electrode laminated body 15 and a frame body 16 arranged so as to surround the electrode laminated body 15. The electrode laminate 15 includes a plurality of electrodes laminated along the stacking direction D of the power storage module 2 via the separator 14. The plurality of electrodes include a plurality of bipolar electrodes 13, a negative electrode terminal electrode 21, and a positive electrode terminal electrode 20.

The bipolar electrode 13 includes an electrode plate 17 including one surface 17a and the other surface 17b on the opposite side of the one surface 17a, a positive electrode active material layer 18 provided on the one surface 17a, and a negative electrode active material provided on the other surface 17b. It has a layer 19. The positive electrode active material layer 18 is formed by applying a positive electrode slurry containing a positive electrode active material to the electrode plate 17. Examples of the positive electrode active material include nickel hydroxide. The negative electrode active material layer 19 is formed by applying a negative electrode slurry containing a negative electrode active material to the electrode plate 17. Examples of the negative electrode active material include hydrogen storage alloys.

In the present embodiment, the formation region of the negative electrode active material layer 19 on the other surface 17b of the electrode plate 17 is slightly larger than the formation region of the positive electrode active material layer 18 on the one side surface 17a of the electrode plate 17. In the electrode laminate 15, the positive electrode active material layer 18 of one bipolar electrode 13 faces the negative electrode active material layer 19 of another bipolar electrode 13 adjacent to one of the stacking directions D with the separator 14 interposed therebetween. In the electrode laminate 15, the negative electrode active material layer 19 of one bipolar electrode 13 faces the positive electrode active material layer 18 of another bipolar electrode 13 adjacent to the other in the stacking direction D with the separator 14 interposed therebetween.

The negative electrode terminal electrode 21 has an electrode plate 17 and a negative electrode active material layer 19 provided on the other surface 17b of the electrode plate 17. The negative electrode terminal electrode 21 is arranged at one end of the stacking direction D so that the other surface 17b faces the center side of the stacking direction D in the electrode laminated body 15. One surface 17a of the electrode plate 17 of the negative electrode terminal electrode 21 constitutes one outer surface in the stacking direction D of the electrode laminate 15, and one conductive plate 5 or a conductive plate P adjacent to the power storage module 2 (see FIG. 1). ) Is electrically connected. The negative electrode active material layer 19 provided on the other surface 17b of the electrode plate 17 of the negative electrode terminal electrode 21 faces the positive electrode active material layer 18 of the bipolar electrode 13 at one end in the stacking direction D via the separator 14.

The positive electrode terminal electrode 20 has an electrode plate 17 and a positive electrode active material layer 18 provided on one surface 17a of the electrode plate 17. The positive electrode terminal electrode 20 is arranged at the other end of the stacking direction D so that one surface 17a faces the center side of the stacking direction D in the electrode laminated body 15. The other surface 17b of the electrode plate 17 of the positive electrode terminal electrode 20 constitutes the other outer surface in the stacking direction D of the electrode laminate 15, and the other conductive plate 5 or the conductive plate P adjacent to the power storage module 2 (see FIG. 1). ) Is electrically connected. The positive electrode active material layer 18 provided on one surface 17a of the positive electrode terminal electrode 20 faces the negative electrode active material layer 19 of the bipolar electrode 13 at the other end in the stacking direction D via the separator 14.

The electrode plate 17 is a conductor having a plate shape extending in the horizontal direction and exhibits flexibility. Therefore, the horizontal direction can be said to be the extending direction of the electrode plate 17. The electrode plate 17 is, for example, a nickel foil, a plated steel plate, or a plated stainless steel plate. Examples of the steel sheet include cold-rolled steel sheets (SPCC and the like) specified in JIS G 3141: 2005. Examples of the stainless steel sheet include SUS304 specified in JIS G 4305: 2015. The thickness of the electrode plate 17 is, for example, 0.1 μm or more and 1000 μm or less. When the electrode plate 17 is a nickel foil, the nickel foil may be plated. The edge portion 17c of the electrode plate 17 (the edge portion of the bipolar electrode 13) has a rectangular frame shape, and is an uncoated region in which the positive electrode slurry and the negative electrode slurry are not coated.

The separator 14 is formed in a sheet shape, for example. Examples of the separator 14 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric made of polypropylene, methyl cellulose and the like, or a non-woven fabric. The separator 14 may be reinforced with a vinylidene fluoride resin compound.

The frame body 16 is formed in a rectangular tubular shape as a whole by, for example, an insulating resin. The frame body 16 is provided on the side surface 15a of the electrode laminated body 15 so as to surround the edge portion 17c of the electrode plate 17. The frame body 16 holds the edge portion 17c on the side surface 15a. The frame body 16 extends to a plurality of first sealing portions 22 coupled to the edge portion 17c of the electrode plate 17 and extends to the side surface 15a along the stacking direction D, and is coupled to each of the first sealing portions 22. It has 2 sealing portions 23. The first sealing portion 22 and the second sealing portion 23 are made of an insulating resin having alkali resistance. Examples of the constituent materials of the first sealing portion 22 and the second sealing portion 23 include polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), and the like.

The first sealing portion 22 is continuously provided on one surface 17a of the electrode plate 17 over the entire circumference of the edge portion 17c, and has a rectangular frame shape when viewed from the stacking direction D. In the present embodiment, the first sealing portion 22 is provided not only on the electrode plate 17 of the bipolar electrode 13, but also on the electrode plate 17 of the negative electrode terminal 21 and the electrode plate 17 of the positive electrode 20. In the negative electrode terminal electrode 21, the first sealing portion 22 is provided on the edge 17c of the one surface 17a of the electrode plate 17, and in the positive electrode terminal 20, both edges of both the one surface 17a and the other surface 17b of the electrode plate 17 are provided. A first sealing portion 22 is provided on 17c.

The first sealing portion 22 is overlapped with the edge portion 17c of the electrode plate 17, and an overlapping portion K is formed. In the overlapping portion K, the first sealing portion 22 is airtightly welded to the electrode plate 17 by, for example, ultrasonic waves or thermocompression bonding. The first sealing portion 22 is formed by using, for example, a film having a predetermined thickness in the stacking direction D. The inside of the first sealing portion 22 is located between the edge portions 17c of the electrode plates 17 adjacent to each other in the stacking direction D. The outside of the first sealing portion 22 projects outward from the edge of the electrode plate 17, and the tip portion thereof is held by the second sealing portion 23. The first sealing portions 22 adjacent to each other along the stacking direction D may be separated from each other or may be in contact with each other. Further, the outer edge portions of the first sealing portion 22 may be bonded to each other by, for example, hot plate welding.

In the electrode laminate 15, a step portion 22s for mounting the edge portion of the separator 14 is provided on the inner edge side of the first sealing portion 22 located in the inner layer in the stacking direction D. The step portion 22s may be formed by folding back the outer edge portion of the film constituting the first sealing portion 22 inward. The step portion 22s may be formed by superimposing the film forming the upper stage on the film forming the lower stage.

The second sealing portion 23 is provided outside the electrode laminate 15 and the first sealing portion 22, and constitutes an outer wall (housing) of the power storage module 2. The second sealing portion 23 is formed, for example, by injection molding of a resin, and extends along the stacking direction D over the entire length of the electrode laminate 15. The second sealing portion 23 has a rectangular frame shape extending with the stacking direction D as the axial direction. The second sealing portion 23 is welded to the outer edge portion of the first sealing portion 22 by, for example, heat during injection molding.

The second sealing portion 23 has overhang portions 23a at both ends in the stacking direction D, respectively. One overhang portion 23a projects toward the inner edge side of the first sealing portion 22 at one end in the stacking direction D, and is welded to one surface 17a of the electrode plate 17 constituting the negative electrode terminal electrode 21. It is bound to 22. The other overhang portion 23a projects toward the inner edge side of the first sealing portion 22 at the other end in the stacking direction D, and is welded to the other surface 17b of the electrode plate 17 constituting the positive electrode terminal electrode 20. It is connected to the part 22. The overhang lengths of one and the other overhang portions 23a are equal to each other, and the tips 24a of these overhang portions 23a overlap the electrode plate 17 and the first sealing portion 22 when viewed from the stacking direction D. It is located so as to overlap the portion K.

The first sealing portion 22 and the second sealing portion 23 form an internal space V between adjacent electrodes and seal the internal space V. More specifically, the second sealing portion 23, together with the first sealing portion 22, is between the bipolar electrodes 13 adjacent to each other along the stacking direction D, and the negative electrode terminal electrodes 21 adjacent to each other along the stacking direction D. And the bipolar electrode 13 and between the positive electrode terminal electrode 20 and the bipolar electrode 13 adjacent to each other along the stacking direction D are sealed. As a result, an airtightly partitioned internal space V is formed between the adjacent bipolar electrodes 13, between the negative electrode terminal 21 and the bipolar electrode 13, and between the positive electrode 20 and the bipolar electrode 13. ing. In the present embodiment, the space surrounded by one surface 17a of the electrode plate 17, the other surface 17b of one electrode plate 17 adjacent to the electrode plate 17, and the first sealing portion 22 is the internal space V. ing. The electrolytic solution is housed in this internal space V. The electrolytic solution is an aqueous electrolytic solution containing an alkaline solution such as an aqueous potassium hydroxide solution. The electrolytic solution is impregnated in the separator 14, the positive electrode active material layer 18, and the negative electrode active material layer 19.

Next, the configuration of the pressure regulating valve 12 will be described in detail with reference to FIGS. 3 to 6. FIG. 4 is an exploded perspective view (including a partial cross-sectional view) showing a part of the power storage module. FIG. 5 is a side view showing a part of the power storage device seen from the Y-axis direction. FIG. 6 is a diagram showing a pressure regulating valve seen from the X-axis direction.

As shown in FIGS. 3 and 4, one wall portion 16a constituting the frame body 16 is provided with a plurality of (here, four) mounting regions 24 for mounting the pressure adjusting valve 12. In each mounting region 24, the frame body 16 has a first communication hole 16b that communicates with the internal space V (see FIG. 2). Each mounting area 24 is provided with a plurality of (six in this case) first communication holes 16b. The first communication holes 16b are arranged in three rows and two stages (three rows in the Y-axis direction and two stages in the Z-axis direction) in each mounting region 24. Therefore, the first communication holes 16b are arranged in 12 rows and 2 steps on the wall portion 16a. Each first communication hole 16b communicates with the internal space V of a different cell.

Each first communication hole 16b includes a communication hole 25 provided in the first sealing portion 22 and a communication hole 26 provided in the second sealing portion 23. The first communication hole 16b functions as a liquid injection hole for injecting the electrolytic solution into the internal space V. Further, the first communication hole 16b becomes a flow path through which the gas generated in the internal space V flows after the electrolytic solution is injected.

In each mounting region 24, the second sealing portion 23 has a substantially frame-shaped protrusion 27. The protrusions 27 join the module body 11 and the pressure regulating valve 12 by heat welding, and form a plurality of (six in this case) flow paths 28 through which gas from each internal space V flows. The flow path 28 is a part of the communication hole 26. The flow path 28 has a rectangular shape in a cross section along a plane perpendicular to the X-axis direction. The protrusions 27 are formed in a grid pattern when viewed from the X-axis direction.

The pressure regulating valve 12 has a case 29, a plurality of (six in this case) valve bodies 30, and a cover 31. The case 29 is made of a resin such as PP, PPS or modified PPE. The case 29 is formed in a substantially rectangular shape when viewed from the opposite direction (X-axis direction) in which the case 29 and the cover 31 face each other. The facing direction is also the mounting direction of the pressure adjusting valve 12 with respect to the module main body 11 (wall portion 16a).

The case 29 has a bottom wall portion 32. On the outer surface 32a of the bottom wall portion 32, a plurality of (six in this case) second communication holes 33 are formed which are communicated with the plurality of first communication holes 16b of the module main body 11. The second communication hole 33 has a circular shape with a cross section along a plane (YZ plane) perpendicular to the X-axis direction. The second communication hole 33 penetrates the bottom wall portion 32. The bottom wall portion 32 has a protrusion 34 protruding toward the module main body 11.

The protrusion 34 has a substantially frame shape and is provided so as to surround the second communication hole 33. The protrusions 34 join the module body 11 and the pressure regulating valve 12 by heat welding, and form a plurality of (six in this case) flow paths through which gas from each internal space V flows. The protrusion 34 is joined to the protrusion 27 of the module main body 11 by heat welding. The protrusion 34 has a shape and dimensions corresponding to the protrusion 27.

The case 29 has a side wall portion 36 and a partition wall portion 37 protruding from the bottom wall portion 32 toward the cover 31, respectively. In the present embodiment, the side wall portion 36 and the partition wall portion 37 are integrally formed with the bottom wall portion 32. The side wall portion 36 is erected at the edge portion of the bottom wall portion 32 so as to surround a plurality of (six in this case) valve bodies 30.

The partition wall portion 37 is erected on the bottom wall portion 32 so as to cover the side surface 30c of each valve body 30. That is, the partition wall portion 37 forms a columnar storage space S1 in which each valve body 30 is housed. In the present embodiment, the accommodating space S1 is formed by the partition wall portion 37 and a part of the side wall portion 36 surrounding the side surface 30c of the valve body 30.

The valve body 30 is housed in the storage space S1 so as to close the second communication hole 33. The valve body 30 is a columnar member formed of an elastic body such as rubber. The valve body 30 includes a first end surface 30a that closes the second communication hole 33, a second end surface 30b that is located on the opposite side of the first end surface 30a, and a side surface 30c that connects the first end surface 30a and the second end surface 30b. have. The first end surface 30a faces the bottom wall portion 32. The second end surface 30b is a pressed surface that faces the cover 31 and is pressed by the cover 31. The valve body 30 closes the second communication hole 33 by arranging the first end surface 30a in a state of being pressed against the bottom wall portion 32. The valve body 30 opens and closes the second communication hole 33 according to the pressure of the internal space V. A gap G is provided between the side surface 30c of the valve body 30 and the inner wall surface of the partition wall portion 37 or the inner wall surface of the side wall portion 36.

The cover 31 is a member that closes the opening of the case 29. The cover 31 is made of a resin such as PP, PPS or modified PPE. The cover 31 is joined to the open end face of the case 29 by welding. The cover 31 also functions as a pressing member that presses the plurality of valve bodies 30 against the bottom wall portion 32 of the case 29. The cover 31 is joined to the open end surface of the case 29 while maintaining the state in which the valve body 30 is pressed against the bottom wall portion 32 of the case. Specifically, the edge portion of the inner surface of the cover 31 is joined to the end portion of the side wall portion 36 by, for example, ultrasonic welding.

The cover 31 has a main body portion 31a joined to the open end surface of the case 29 and an inclined portion 31b connected to the main body portion 31a. The main body portion 31a is a plate-shaped portion having a rectangular shape when viewed from the X-axis direction. The inclined portion 31b is connected to the lower end of the main body portion 31a. The inclined portion 31b is a plate-shaped portion having a rectangular shape when viewed from the plate thickness direction. The thickness of the inclined portion 31b may be less than or equal to the thickness of the main body portion 31a.

The case 29 and the main body 31a form a housing 50 that houses the valve body 30. The housing 50 has an outer surface 32a of the bottom wall portion 32, which is the first surface on which the second communication hole 33 is formed, and a main body portion, which is the second surface arranged on the opposite side of the valve body 30 from the outer surface 32a. The side surface 31s of 31a, the pair of side surfaces 50a which are the third surfaces connecting the outer surface 32a and the side surface 31s, and the upper surface 50b and the lower surface which are the fourth surfaces connecting the outer surface 32a and the side surface 31s and the pair of side surfaces 50a. It includes 50c (see FIGS. 3 to 5). The pair of side surfaces 50a, upper surface 50b, and lower surface 50c are outer surfaces of the side wall portion 36 of the case 29. In the present embodiment, the side surface 31s extends along the Z-axis direction and the Y-axis direction. The pair of side surfaces 50a extend along the Z-axis direction and the X-axis direction. The Z-axis direction is, for example, the vertical direction (gravity direction), and the X-axis direction and the Y-axis direction are, for example, the horizontal direction. The side surface 31s and the pair of side surfaces 50a are, for example, parallel to the vertical direction, but may be parallel to the direction inclined at an angle of, for example, 10 ° or less with respect to the vertical direction.

The side surface 31s of the main body 31a is provided with an exhaust port 41 for discharging the gas generated in the internal space V, passing through the first communication hole 16b and the second communication hole 33, and flowing into the housing 50. .. In the present embodiment, as an example, exhaust ports 41 having a circular cross section extending in the X-axis direction are provided at each of the pair of diagonal portions of the main body portion 31a having a rectangular plate shape. The exhaust port 41 is arranged so as not to overlap the valve body 30 when viewed from the opposite direction. The position and shape of the exhaust ports 41 and the number of exhaust ports 41 are not limited to this example.

The inclined portion 31b is located below the exhaust port 41 in the direction of gravity. The inclined portion 31b has an upper end 31f connected to the housing 50 and a lower end 31e. The inclined portion 31b has an inclined surface 31t inclined with respect to the side surface 31s. The inclined surface 31t is connected to the lower end of the side surface 31s. The inclined surface 31t is a plane having a rectangular shape when viewed from the normal direction of the inclined surface 31t. As shown in FIG. 5, the inclined surface 31t extends along the central axial direction H1a of the exhaust port 41 and inclines downward in the gravity direction from the proximal end side connected to the housing 50 to the tip end. The central axial direction H1a passes through the center of the exhaust port 41. The central axis direction H1a is a direction from the inside of the housing 50 toward the outside of the housing 50 via the exhaust port 41. That is, the central axis direction H1a is the direction from the exhaust port 41 toward the outside of the housing 50 in the direction H1 (X-axis direction) intersecting (orthogonal) with the side surface 31s provided with the exhaust port 41. "Extending along the central axis direction H1a" means extending in the direction having the component of the central axis direction H1a. The inclined surface 31t is inclined downward as it is separated from the side surface 31s in the normal direction of the side surface 31s. In the XZ cross section, the inclined surface 31t extends from the base end to the tip end in the inclined direction I. The angle (acute angle) θ formed by the inclination direction I of the inclined surface 31t and the central axis direction H1a may be 10 ° or more, 20 ° or more, or 30 ° or more. ..

As shown in FIG. 6, in the width direction H2 seen from the central axis direction H1a, the length L2 of the inclined surface 31t is longer than the length L1 of the exhaust port 41. The width direction H2 is the left-right direction (Y-axis direction) when viewed from the central axis direction H1a. The width direction H2 is along the side surface 31s provided with the exhaust port 41. The length L2 of the inclined surface 31t may be substantially the same as the total length of the pressure regulating valve 12 in the width direction H2. In the width direction H2, the length L2 of the inclined surface 31t may be substantially the same as the length L1 of the exhaust port 41. That is, in the width direction H2, the inclined surface 31t may be provided only at the same position as the exhaust port 41.

The upper power storage module 2 (second power storage module) stacked on the lower power storage module 2 (first power storage module) in the stacking direction D has a pressure adjusting valve 12 having an inclined portion 31b. The lower end 31e of the inclined portion 31b of the upper power storage module 2 overlaps with the lower power storage module 2 when viewed from the central axial direction H1a.

Subsequently, the operation of the pressure regulating valve 12 will be described. As shown in FIG. 4, in the pressure regulating valve 12, the second communication hole 33 of the case 29 communicates with the internal space V of the module main body 11 via the first communication hole 16b of the frame body 16. When the pressure in the internal space V is lower than the set pressure, the second communication hole 33 is maintained in a closed state in which the valve body 30 closes. When the pressure in the internal space V rises to exceed the set pressure, the valve body 30 is elastically deformed so as to be separated from the bottom wall portion 32, and the valve opening state in which the second communication hole 33 is released is released. As a result, the gas from the internal space V is discharged from the exhaust port 41 to the outside of the pressure adjusting valve 12 through the gap G (accommodation space S1) between the side surface 30c of the valve body 30 and the inner wall surface of the partition wall portion 37. Will be done.

In the power storage module 2, when the gas generated in the internal space V is discharged from the exhaust port 41, the electrolytic solution may be discharged together. In this case, the electrolytic solution discharged from the exhaust port 41 flows downward along the side surface 31s of the pressure regulating valve 12, and then flows downward along the inclined inclined surface 31t. After that, the electrolytic solution falls from the lower end of the inclined surface 31t. Here, the inclined surface 31t extends along the central axis direction H1a and is inclined downward in the gravity direction from the proximal end side connected to the housing 50 to the distal end. Therefore, the power storage module 2 rotates about the Y-axis direction by an angle smaller than the angle (acute angle) θ formed by the central axial direction H1a and the inclined direction I of the inclined surface 31t so that the exhaust port 41 moves upward. Even if it is tilted, the lower end of the inclined surface 31t is located below the upper end of the inclined surface 31t. Therefore, in the power storage module 2, the electrolytic solution discharged from the exhaust port 41 of the pressure adjusting valve 12 travels along the surface of the pressure adjusting valve 12 and goes from the exhaust port 41 toward the inside of the housing 50 (opposite to the central axial direction H1a). It is possible to suppress the flow in the direction). Therefore, it is possible to prevent the electrolytic solution from flowing along the surface of the pressure regulating valve 12 toward the module main body 11. As a result, it is possible to prevent a short circuit caused by the electrolytic solution entering between the adjacent power storage modules 2.

When the length L2 of the inclined surface 31t is longer than the length L1 of the exhaust port 41 in the width direction H2, all or most of the electrolytic solution discharged from the exhaust port 41 flows on the inclined surface 31t. Therefore, it is possible to further suppress the electrolytic solution discharged from the pressure regulating valve 12 from flowing along the surface of the power storage module 2 toward the module main body 11.

In the power storage device 1 in which the lower end 31e of the inclined portion 31b of the upper power storage module 2 overlaps with the lower power storage module 2 when viewed from the central axis direction H1a, the electrolytic solution dropped from the lower end of the inclined surface 31t is stored in the lower power storage module 2. It is possible to suppress the flow between the module 2 and the upper power storage module 2.

FIG. 7 is a cross-sectional view showing an inclined portion of the pressure regulating valve according to the modified example. The pressure adjusting valve according to the modified example has the same configuration as the pressure adjusting valve 12 except that the inclined portion 131b is provided instead of the inclined portion 31b. The inclined portion 131b has the same configuration as the inclined portion 31b except that it has an inclined surface 131t instead of the inclined surface 31t. In the width direction H2, the inclined surface 131t is inclined downward from both ends of the inclined surface 131t toward the center. That is, the inclined surface 131t has a V shape in a YZ cross section orthogonal to the X-axis direction. In this case, it is possible to suppress the flow of the electrolytic solution from both ends of the inclined surface 131t to the outside in the width direction H2.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment.

For example, in the above embodiment, the inclined portions 31b and 131b are connected to the side surface 31s of the cover 31 of the pressure regulating valve 12, but the inclined portions 31b and 131b are connected to other parts of the housing 50 (for example, the case 29 and the like). May be done. The inclined portions 31b and 131b may be connected to the lower surface 50c of the housing 50.

The exhaust port 41 may be provided on at least one of the pair of side surfaces 50a. In this case, the inclined portions 31b and 131b are connected to the side surface 50a or the lower surface 50c provided with the exhaust port 41. The inclined surfaces 31t and 131t extend along the central axis direction of the exhaust port 41 and are inclined downward in the direction of gravity from the proximal end side connected to the housing 50 to the tip end. That is, the inclined surfaces 31t and 131t are inclined downward as they are separated from the side surface 50a in the normal direction of the side surface 50a provided with the exhaust port 41. As a result, even if the power storage module 2 rotates and tilts about the X-axis direction so that the exhaust port 41 moves upward, the lower end of the inclined surface 31t is located below the upper end of the inclined surface 31t.

The housing 50 may have, for example, a cylindrical shape with the X-axis direction as the central axis. In this case, the side surface 31s has a circular shape. The housing 50 does not have an upper surface 50b, a lower surface 50c and a pair of side surfaces 50a, but has a cylindrical surface (third surface of the housing 50). The exhaust port 41 may be provided on the side surface 31s or on the cylindrical surface. When the exhaust port 41 is provided on the side surface 31s as in the embodiment shown in FIGS. 3 to 6, the inclined portions 31b and 131b may be connected to the side surface 31s or below the exhaust port 41 in the cylindrical surface. It may be connected to a portion located at. On the other hand, when the exhaust port 41 is provided on the cylindrical surface, the inclined portions 31b and 131b are connected to a portion of the cylindrical surface located below the exhaust port 41. The inclined surfaces 31t and 131t extend along the central axis direction of the exhaust port 41 and are inclined downward in the direction of gravity from the proximal end side connected to the housing 50 to the tip end.

In the above embodiment, the inclined surfaces 31t and 131t are connected to the lower end of the side surface 31s, but the inclined surfaces 31t and 131t may be connected between the lower end of the side surface 31s and the exhaust port 41.

In the above embodiment, when viewed from the central axis direction H1a, the lower end 31e of the inclined portion 31b of the upper power storage module 2 overlaps with the lower power storage module 2, but the lower end 31e of the inclined portion 31b of the upper power storage module 2 overlaps. It does not have to overlap with the power storage module 2 below.

Further, wall surfaces protruding upward may be provided at both ends of the inclined surfaces 31t and 131t in the width direction H2. In this case, it is possible to suppress the flow of the electrolytic solution from both ends of the inclined surfaces 31t and 131t to the outside in the width direction H2.

1 ... Power storage device, 2 ... Power storage module, 11 ... Module body, 12 ... Pressure regulating valve, 13 ... Bipolar electrode (electrode), 15 ... Electrode laminate, 16 ... Frame body, 16b ... First communication hole, 20 ... Positive electrode Termination electrode (electrode), 21 ... Negative electrode Termination electrode (electrode), 30 ... Valve body, 31b, 131b ... Inclined portion, 31e ... Lower end, 31f ... Upper end, 31s ... Side surface (second surface), 31t, 131t ... Inclined surface , 32a ... outer surface (first surface), 33 ... second communication hole, 41 ... exhaust port, 50 ... housing, 50a ... side surface (third surface), H1a ... central axis direction, H2 ... width direction, V ... internal space ..

Claims (4)

An electrode laminate having a plurality of stacked electrodes, and a frame having a first communication hole arranged so as to surround the electrode laminate and communicated with an internal space formed between the plurality of adjacent electrodes. Module body with
The pressure control valve attached to the module body and
With
The electrolytic solution is housed in the internal space.
The pressure regulating valve includes a housing having a second communication hole that communicates with the first communication hole, and a valve body that is housed in the housing and closes the second communication hole.
The housing has a first surface on which the second communication hole is formed, a second surface arranged on the side opposite to the first surface with the valve body interposed therebetween, and the first surface and the second surface. Has a third surface that connects with
The second surface or the third surface is provided with an exhaust port for discharging the gas generated in the internal space, passing through the first communication hole and the second communication hole, and flowing into the housing. ,
The pressure regulating valve is connected to the housing and includes an inclined portion located downward in the direction of gravity of the exhaust port.
The storage module has an inclined surface that extends along the central axis direction of the exhaust port and is inclined downward in the direction of gravity from the base end side connected to the housing to the tip end. The power storage module according to claim 1, wherein the length of the inclined surface is longer than the length of the exhaust port in the width direction viewed from the central axis direction. The power storage module according to claim 1 or 2, wherein in the width direction viewed from the central axis direction, the inclined surface is inclined downward from both ends of the inclined surface toward the center. A power storage device including a first power storage module and a second power storage module stacked on the first power storage module.
The second power storage module is the power storage module according to any one of claims 1 to 3.
A power storage device in which the lower end of the inclined portion overlaps with the first power storage module when viewed from the central axis direction.

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