Energy storage module

Abstract

To provide an electric power storage module configured to prevent an electrolyte from spattering.SOLUTION: An electric power storage module comprises: a module body having an electrode stack including a plurality of stacked electrodes; and a pressure-regulating valve 22 attached to the module body. The pressure-regulating valve 22 is provided with: a housing 23 having a bottom wall 32 provided with a through hole 33 that communicates with an internal space that is formed between the plurality of electrodes and accommodates an electrolyte, a side wall 40 facing the bottom wall 32 in a Y-axis direction, and a protrusion 43 provided on the side wall 40; and a valve 30 accommodated inside the housing 23 so as to close off the through hole 33. The side wall 40 is provided with a first hole 41 that is open on an external surface 40a of the side wall 40, and a second hole 42 that is open on the external surface 40a of the side wall 40 and positioned vertically above the first hole 41. The protrusion 43 protrudes outward along the Y-axis direction on the external surface 40a and extends so as to divide the first hole 41 and the second hole 42 when viewed from the Y-axis direction.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present disclosure relates to a power storage module.

Background Art

[0002] Patent Document 1 describes a power storage module including a module body formed by laminating a plurality of electrodes, and a pressure regulating valve attached to the module body. This pressure regulating valve includes a housing and a valve body housed in the housing. The housing is provided with a communication hole communicating with an internal space formed between a plurality of electrodes and storing an electrolytic solution, and an exhaust port for discharging gas generated from the plurality of electrodes, flowing through the communication hole from the internal space, and flowing into the housing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above pressure regulating valve, when gas is discharged from the exhaust port, the electrolytic solution may be discharged together. In this case, there is a risk that the electrolytic solution will be scattered by the gas.

[0005] An object of the present disclosure is to provide a power storage module capable of suppressing scattering of the electrolytic solution.

Means for Solving the Problems

[0006] A power storage module according to one aspect of the present disclosure comprises a module body having an electrode stack including a plurality of stacked electrodes, and a pressure regulating valve attached to the module body. The pressure regulating valve comprises a housing having a first wall with a communication hole that communicates with an internal space formed between the plurality of electrodes and containing an electrolyte, a second wall facing the first wall in a first direction intersecting the vertical direction, and a first projection provided on the second wall, and a valve body housed in the housing so as to close the communication hole. The second wall is provided with a first hole that communicates the inside and outside of the housing and opens to the outer wall surface of the second wall, and a second hole that communicates the inside and outside of the housing and opens to the outer wall surface, and is located vertically above the first hole. The first projection protrudes outward along the first direction on the outer wall surface and extends so as to separate the first hole and the second hole when viewed from the first direction.

[0007] In the above-described energy storage module, a first hole and a second hole located vertically above the first hole are provided on the outer surface of the second wall of the housing. The electrolyte is discharged by dripping from the first hole located vertically below. On the other hand, gases such as hydrogen gas and oxygen gas generated in the energy storage module are lighter than air, so they are discharged from the second hole located vertically above. Furthermore, a first projection is provided on the outer surface of the second wall, which protrudes outward and extends to separate the first and second holes. In other words, the first projection is provided so as to be interposed between the discharge path of the electrolyte discharged from the first hole and the discharge path of the gas discharged from the second hole. Therefore, the gas discharged from the second hole is blocked by the first projection and is less likely to come into contact with the electrolyte discharged from the first hole. As a result, splashing of the electrolyte can be suppressed.

[0008] When viewed from the first direction, the length of the first projection in the second direction intersecting the vertical direction is greater than or equal to the length of the first and second holes in the second direction, and the first projection may extend so as to completely cover the upper side of the first hole and the lower side of the second hole when viewed from the first direction. In this case, since the first projection can completely cover the upper side of the first hole and the lower side of the second hole, the gas discharged from the second hole is less likely to come into contact with the electrolyte discharged from the first hole. Therefore, splashing of the electrolyte can be further suppressed.

[0009] The first and second holes may be arranged so as not to overlap each other in the vertical direction. In this case, the gas discharged from the second hole is further suppressed from coming into contact with the electrolyte discharged from the first hole.

[0010] The housing may further have a plurality of second protrusions provided on its outer surface so as to surround the first hole and the second hole, respectively, along with the first protrusion. In this case, the gas discharged from the second hole is less likely to spread to the surroundings. Therefore, the gas discharged from the second hole is further prevented from coming into contact with the electrolyte discharged from the first hole.

[0011] Multiple internal spaces are formed, and multiple communication holes are arranged in a third direction that intersects the vertical direction when viewed from the first direction, communicating with each of the multiple internal spaces, and multiple second holes may also be arranged in a third direction. In this case, not only are multiple communication holes arranged in a third direction, but multiple second holes are also arranged in a third direction, so the path from each communication hole to the second hole can be shortened. This prevents gas flowing in from each communication hole from being discharged from the first hole on its way to the second hole.

[0012] The first holes may be arranged in a third direction that intersects the vertical direction when viewed from the first direction. In this case, the amount of electrolyte discharged from each first hole is reduced. This suppresses short circuits between adjacent energy storage modules through the electrolyte discharged from the pressure regulating valve. [Effects of the Invention]

[0013] According to this disclosure, it is possible to provide an energy storage module that can suppress the splashing of electrolyte. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a cross-sectional view showing an energy storage device equipped with an energy storage module according to one embodiment. [Figure 2] Figure 2 is a cross-sectional view taken along line II-II of Figure 1. [Figure 3] Figure 3 is a cross-sectional view showing the power storage module. [Figure 4] Figure 4 is a perspective view showing the power storage module. [Figure 5] Figure 5 is an exploded perspective view showing a part of the power storage module. [Figure 6] Figure 13 is an exploded perspective view of the pressure regulating valve. [Figure 7] Figure 16 is a bottom view of the pressure regulating valve. [Figure 8] Figure 19 is a plan view of the case. [Figure 9] Figure 22 is a plan view of the cover. [Figure 10] Figure 25 is a plan view showing an enlarged part of the cover. [Figure 11] Figure 28 is a plan view of the pressure regulating valve. [Figure 12] Figure 31 is a cross-sectional view taken along line XII-XII of Figure 11.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and duplicate descriptions are omitted. In the drawings, an XYZ orthogonal coordinate system is shown as necessary. The Z-axis direction is, for example, the vertical direction, and the X-axis direction (the second direction and the third direction) and the Y-axis direction (the first direction) are, for example, the horizontal directions.

[0016] It should be noted that in the original text, there is no "図13" and "図16" in the content you provided. I have translated it according to the existing text, but you may need to check if there are any errors in the original text. Also, for the sake of consistency, I have translated "

発明を実施するための形態

Embodiments for Carrying Out the Invention

[0017] The module laminate 2 includes a plurality (here, three) of electric storage modules 4 and a plurality (here, two) of conductive plates 5. The electric storage module 4 is, for example, a bipolar battery and has a rectangular shape when viewed from the Z-axis direction. More specifically, the electric storage module 4 has a rectangular shape having a long side and a short side when viewed from the Z-axis direction. The electric storage module 4 is, for example, a secondary battery such as a nickel-hydrogen battery, a lithium-ion battery, or a lead battery, or an electric double layer capacitor. In the following description, a nickel-hydrogen secondary battery will be exemplified.

[0018] In the module laminate 2, a conductive plate 5 is interposed between adjacent electric storage modules 4 along the Z-axis direction. Thereby, the plurality of electric storage modules 4 are electrically connected via the conductive plate 5. More specifically, each electric storage module 4 includes a positive electrode terminal surface on one end surface in the Z-axis direction and a negative electrode terminal surface on the other end surface in the Z-axis direction, and the plurality of electric storage modules 4 laminated via the conductive plate 5 are connected in series. Outside the electric storage module 4 located at one end in the Z-axis direction of the module laminate 2, a current collector plate 6 from which a positive electrode terminal 6a is drawn out is disposed and electrically connected to the electric storage module 4. Also, outside the electric storage module 4 located at the other end in the Z-axis direction of the module laminate 2, a current collector plate 7 from which a negative electrode terminal 7a is drawn out is disposed and electrically connected to the electric storage module 4. By using these positive electrode terminal 6a and negative electrode terminal 7a, charging and discharging of the electric storage device 1 are performed.

[0019] Multiple flow channels 5a are provided inside the conductive plate 5 for circulating a coolant such as air. The flow channels 5a extend in a direction (in this case, the X-axis direction) that intersects (is perpendicular to) the Z-axis direction and the direction in which the positive terminal 6a and negative terminal 7a are drawn out. In addition to functioning as a connecting member that electrically connects the energy storage modules 4 together, the conductive plate 5 also functions as a heat dissipation member that dissipates heat generated in the energy storage modules 4 by circulating the coolant through these flow channels 5a.

[0020] The restraining member 3 includes a pair of restraining plates 8 that sandwich the module stack 2 in the stacking direction, a plurality of fasteners 9 such as bolts that connect the restraining plates 8 by fastening them together, and a support column 10 that houses the main body of the fasteners 9 (for example, the shaft of a bolt). The restraining plate 8 is a rectangular metal plate having an area slightly larger than the area of ​​the energy storage module 4 and conductive plate 5 as viewed from the first direction. The restraining plate 8 is rectangular in shape with a long side and a short side when viewed from the Z-axis direction. A plate-shaped insulating member F is provided on the inner surface of the restraining plate 8 (the surface facing the module stack 2). That is, a current collector plate 6 or current collector plate 7 and the insulating member F are interposed between the module stack 2 and the restraining plate 8. This provides insulation between the restraining plate 8 and the module stack 2 (current collector plates 6, 7).

[0021] An insertion hole 8a is provided on the edge of one restraint plate 8 at a position outside the module stack 2 when viewed from the Z-axis direction, and a screw hole 8b is provided on the edge of the other restraint plate 8 at a position opposite to the insertion hole 8a. The fastener 9 is passed through the insertion hole 8a of one restraint plate 8 towards the screw hole 8b of the other restraint plate 8 and screwed into the screw hole 8b of the other restraint plate 8. As a result, the energy storage module 4 and the conductive plate 5 are sandwiched by the restraint plates 8 and unitized as a module stack 2, and a restraining load is applied to the module stack 2 along the Z-axis direction.

[0022] Thus, the fastener 9 is positioned on the outside of the module stack 2 (the second seal portion 12 described later), extends along the Z-axis direction, and restrains the module stack 2 (the electrode stack 11 described later) by fastening a pair of restraint plates 8 together along the Z-axis direction. The support column 10 is interposed between the pair of restraint plates 8 and extends along the Z-axis direction together with the fastener 9. The support column 10 defines the restraining force on the module stack 2 by defining the distance between the pair of restraint plates 8 in the Z-axis direction.

[0023] In the energy storage device 1, multiple connecting members, each consisting of one fastener 9 and one support column 10 housing the fastener 9, are arranged along the long side of the restraint plate 8 when viewed from the Z-axis direction. Furthermore, when viewed from the Z-axis direction, the connecting members face each other in a direction along the short side of the restraint plate 8. The closer these opposing connecting members are to each other, the more uniformly a restraining load can be applied to the energy storage module 4 via the restraint plate 8.

[0024] Next, the configuration of the energy storage module 4 will be described in detail. Figure 3 is a cross-sectional view showing the energy storage module. Figure 4 is a perspective view showing the energy storage module. As shown in Figures 3 and 4, the energy storage module 4 includes a module body 20 and a pressure regulating valve 22 attached to the module body 20. The module body 20 includes an electrode stack 11 and a second resin seal portion 12 that seals the electrode stack 11. The electrode stack 11 includes a plurality of electrodes (a plurality of bipolar electrodes 14, a negative terminal electrode 18, and a positive terminal electrode 19) stacked along the Z-axis direction via a separator 13. Here, the stacking direction of the electrodes coincides with the stacking direction of the energy storage module 4.

[0025] The bipolar electrode 14 includes an electrode plate 15 with a first surface 15a and a second surface 15b opposite to the first surface 15a, a positive electrode active material layer 16 provided on the first surface 15a, and a negative electrode active material layer 17 provided on the second surface 15b. In the electrode stack 11, the positive electrode active material layer 16 of one bipolar electrode 14 faces the negative electrode active material layer 17 of another bipolar electrode 14 adjacent in the Z-axis direction, separated by a separator 13. In the electrode stack 11, the negative electrode active material layer 17 of one bipolar electrode 14 faces the positive electrode active material layer 16 of yet another bipolar electrode 14 adjacent in the Z-axis direction, separated by a separator 13.

[0026] The negative electrode terminal electrode 18 includes an electrode plate 15 and a negative electrode active material layer 17 provided on the second surface 15b of the electrode plate 15. The first surface 15a of the electrode plate 15 of the negative electrode terminal electrode 18 does not have an active material layer. The negative electrode terminal electrode 18 is positioned at one end of the electrode stack 11 in the Z-axis direction such that its second surface 15b faces the inside of the electrode stack 11 (towards the center in the Z-axis direction). The negative electrode active material layer 17 of the negative electrode terminal electrode 18 faces the positive electrode active material layer 16 of the bipolar electrode 14 at one end in the Z-axis direction, via a separator 13.

[0027] The positive terminal electrode 19 includes an electrode plate 15 and a positive electrode active material layer 16 provided on the first surface 15a of the electrode plate 15. The second surface 15b of the electrode plate 15 of the positive terminal electrode 19 does not have an active material layer. The positive terminal electrode 19 is positioned at the other end of the electrode stack 11 in the Z-axis direction such that its first surface 15a is on the inside of the electrode stack 11. The positive electrode active material layer 16 of the positive terminal electrode 19 faces the negative electrode active material layer 17 of the bipolar electrode 14 at the other end in the Z-axis direction, via a separator 13.

[0028] The first surface 15a of the electrode plate 15 of the negative terminal electrode 18 is the surface facing the outside of the electrode stack 11. A conductive plate 5 is electrically connected to the first surface 15a of the negative terminal electrode 18 via a metal plate 50, which will be described later. The second surface 15b of the electrode plate 15 of the positive terminal electrode 19 is also the surface facing the outside of the electrode stack 11. Another conductive plate 5 is electrically connected to the second surface 15b of the positive terminal electrode 19 via a metal plate 50, which will be described later.

[0029] The electrode plate 15 is made of a metal such as nickel or nickel-plated steel. For example, the electrode plate 15 is a rectangular metal foil made of nickel. The peripheral edge 15c of the electrode plate 15 (the peripheral edge of the bipolar electrode 14, the negative electrode terminal electrode 18, and the positive electrode terminal electrode 19) is rectangular in shape and is a region where the positive electrode active material layer 16 and the negative electrode active material layer 17 are not formed. Examples of positive electrode active materials that constitute the positive electrode active material layer 16 include nickel hydroxide. Examples of negative electrode active materials that constitute the negative electrode active material layer 17 include hydrogen storage alloys.

[0030] The separator 13 is formed, for example, in the form of a sheet. Examples of the separator 13 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or nonwoven fabrics made of polypropylene, polyethylene terephthalate (PET), methylcellulose, etc. The separator 13 may also be reinforced with a vinylidene fluoride resin compound.

[0031] The electrode laminate 11 includes a plurality of first sealing portions 21 made of insulating resin. Each of the plurality of first sealing portions 21 includes a first portion 21a, a second portion 21b, and a third portion 21c. The first portion 21a is formed in the shape of a rectangular frame when viewed from the Z-axis direction and is joined (e.g., welded) to the peripheral edge 15c of the electrode plate 15. The second portion 21b is also in the shape of a rectangular frame when viewed from the Z-axis direction and is positioned on a part of the first portion 21a. That is, when viewed from the Z-axis direction, the inner edge of the second portion 21b is located outside the inner edge of the first portion 21a. The separator 13 is positioned and joined (e.g., welded) to the portion of the first portion 21a that is exposed from the second portion 21b.

[0032] The third portion 21c has a rectangular cylindrical shape extending along the Z-axis and is formed by joining and integrating a plurality of first portions 21a and a plurality of second portions 21b. The first portions 21a and second portions 21b can be formed, for example, by folding a single sheet-like member. In this case, the third portion 21c is a welded end formed, for example, by welding the folded portion of the sheet-like member (the outer end of the first portion 21a and second portion 21b).

[0033] The second seal portion 12 is formed in an overall rectangular cylindrical shape, for example, from an insulating resin. The second seal portion 12 is provided around the electrode stack 11 so as to surround the electrode stack 11. The second seal portion 12 is joined (e.g., welded) to the first seal portion 21 so as to surround the first seal portion 21 from the outside. The second seal portion 12 is formed, for example, by resin injection molding and extends along the entire length of the electrode stack 11 in the Z-axis direction. The second seal portion 12 is welded to the outer surface of the first seal portion 21, for example, by the heat during injection molding.

[0034] The first seal portion 21 and the second seal portion 12 seal the spaces between adjacent bipolar electrodes 14 along the Z-axis, between the negative terminal electrode 18 and the bipolar electrode 14, and between the positive terminal electrode 19 and the bipolar electrode 14, respectively. As a result, airtight internal spaces V are formed between the bipolar electrodes 14, between the negative terminal electrode 18 and the bipolar electrode 14, and between the positive terminal electrode 19 and the bipolar electrode 14. In other words, the first seal portion 21 and the second seal portion 12 are for forming the internal spaces V between the electrodes and sealing the internal spaces V. This internal space V contains an electrolyte (not shown) consisting of an alkaline solution such as an aqueous potassium hydroxide solution. At least a portion of the electrolyte can be impregnated into the separator 13, the positive electrode active material layer 16, and the negative electrode active material layer 17.

[0035] The first sealing portion 21 and the second sealing portion 12 may be made of an insulating resin, such as polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE).

[0036] As shown in Figures 1 to 4, the second seal portion 12 includes a pair of outer peripheral surfaces 12s and a pair of outer peripheral surfaces 12r connecting the two outer peripheral surfaces 12s. The outer peripheral surfaces 12s and 12r are surfaces that extend along the Z-axis direction. Here, the outer peripheral surface 12s is a surface that intersects (is perpendicular to) the X-axis direction, and the outer peripheral surface 12r is a surface that intersects (is perpendicular to) the Y-axis direction. Also, the length of the outer peripheral surface 12s in the Y-axis direction is longer than the length of the outer peripheral surface 12r in the X-axis direction. In the conductive plate 5 described above, the flow path 5a extends along the X-axis direction and opens to a pair of surfaces of the conductive plate 5 that intersect in the X-axis direction.

[0037] Therefore, the gap on the outer peripheral surface 12s side of the second seal portion 12 of adjacent energy storage modules 4 is used for the introduction and discharge of refrigerant to the flow path 5a (the refrigerant passes through it). On the other hand, the gap on the outer peripheral surface 12r side of the second seal portion 12 of adjacent energy storage modules 4 is not used for the introduction and discharge of refrigerant to the flow path 5a. For this reason, in the module stack 2, the gap on the outer peripheral surface 12s side of the second seal portion 12 of adjacent energy storage modules 4 is open, and the gap on the outer peripheral surface 12r side is sealed by the sealing material E.

[0038] Here, the energy storage module 4 may include a pair of metal plates 50. In this embodiment, the metal plates 50 are provided at one end (the end on the negative terminal electrode 18 side) and the other end (the end on the positive terminal electrode 19 side) of the electrode stack 11 in the Z-axis direction. One of the pair of metal plates 50 contacts the first surface 15a of the electrode plate 15 of the negative terminal electrode 18 with the conductive plate 5. The other of the pair of metal plates 50 contacts the second surface 15b of the electrode plate 15 of the positive terminal electrode 19 with another conductive plate 5. In this way, in the energy storage module 4, the metal plates 50 are provided further outside the negative terminal electrode 18 and the positive terminal electrode 19. The metal plate 50 located at one end in the Z-axis direction (negative terminal electrode 18) constitutes the negative terminal surface of the energy storage module 4. The metal plate 50 located at the other end in the Z-axis direction (positive terminal electrode 19) constitutes the positive terminal surface of the energy storage module 4.

[0039] One peripheral edge of the pair of metal plates 50 is sandwiched between a first portion 21a of a first seal portion 21 provided on the electrode plate 15 of the negative electrode terminal electrode 18 and another first portion 21a provided on the opposite side of the first portion 21a. These pair of first portions 21a are joined (e.g., welded) together by a third portion 21c. The other peripheral edge of the pair of metal plates 50 is sandwiched between a first portion 21a of a first seal portion 21 provided on the electrode plate 15 of the positive electrode terminal electrode 19 and another first portion 21a provided on the opposite side of the first portion 21a. These pair of first portions 21a are also joined (e.g., welded) together by a third portion 21c. The metal plates 50 are metal foils (uncoated foils), such as the electrode plate 15, on which no active material layer is formed.

[0040] As shown in Figure 4, one outer peripheral surface 12r of the second seal portion 12 is provided with a plurality (four in this case) of mounting areas 24 for attaching a pressure regulating valve 22. The plurality of mounting areas 24 are spaced apart from each other in the X-axis direction. In one example, one pressure regulating valve 22 is attached to two adjacent mounting areas 24 in the X-axis direction.

[0041] Figure 5 is an exploded perspective view showing a part of the energy storage module. As shown in Figure 5, in each mounting area 24, the second seal portion 12 is provided with a through hole 12h that penetrates the second seal portion 12 in the Y-axis direction. The first seal portion 21 is provided with a through hole 21h that penetrates the first seal portion 21 in the Y-axis direction and connects the through hole 12h to the internal space V (see Figure 3). Each mounting area 24 is provided with multiple (six in this case) through holes 12h. The through holes 12h are arranged in 3 rows and 2 columns (3 rows in the X-axis direction and 2 columns in the Z-direction) in each mounting area 24. Therefore, the through holes 12h are arranged in 12 rows and 2 columns on the outer circumferential surface 12r.

[0042] In the first seal portion 21, through-holes 21h are provided in areas corresponding to each mounting area 24, with a one-to-one correspondence between each through-hole 12h and the corresponding area. The number of through-holes 21h is the same as the number of through-holes 12h. The through-holes 21h are in communication with the internal spaces V of different cells. The through-holes 12h and 21h function as injection holes for injecting electrolyte into the internal space V. After the electrolyte is injected, the through-holes 12h and 21h become channels through which gas generated in the internal space V (for example, hydrogen gas in the case of a nickel-metal hydride battery) flows.

[0043] Each mounting area 24 of the second seal portion 12 is provided with a roughly frame-shaped joining projection 27 on its outer surface. The joining projection 27 joins the module body 20 and the pressure regulating valve 22, and in cooperation with the through holes 12h and 21h, forms multiple (six in this case) flow channels 28 through which gas from each internal space V flows. Therefore, the flow channels 28 are arranged in 3 rows and 2 columns in each mounting area 24. The flow channels 28 have a rectangular shape in cross-section along a plane perpendicular to the Y-axis direction. The joining projection 27 is formed in a grid pattern when viewed from the Y-axis direction.

[0044] Next, the configuration of the pressure regulating valve 22 attached to the module body 20 will be described in detail. Figure 6 is an exploded perspective view of the pressure regulating valve. Figure 7 is a bottom view of the pressure regulating valve. Figure 8 is a plan view of the case. Figure 9 is a plan view of the cover. Figure 10 is a plan view showing an enlarged portion of the cover. Figure 11 is a plan view of the pressure regulating valve. Figure 12 is a cross-sectional view along line XII-XII in Figure 11.

[0045] As shown in Figures 5 to 12, the pressure regulating valve 22 has a housing 23 and a plurality (12 in this case) of valve bodies 30. The housing 23 includes a case 29 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 opposing direction where the case 29 and the cover 31 face each other. The opposing direction is the mounting direction of the pressure regulating valve 22 to the outer circumferential surface 12r of the module body 20, and is also the compression direction of the valve body 30, which will be described later. The pressure regulating valve 22 is mounted to the module body 20 in a direction perpendicular to the outer circumferential surface 12r. Therefore, the opposing direction of the case 29 and the cover 31 coincides with the Y-axis direction.

[0046] Case 29 has a bottom wall 32 (first wall). The bottom wall 32 faces the outer circumferential surface 12r of the module body 20 in the Y-axis direction. The bottom wall 32 is provided with a plurality of (12 in this case) through holes 33 (communication holes) that penetrate the bottom wall 32 in the Y-axis direction. The plurality of through holes 33 are arranged side by side in the X-axis direction.

[0047] The through-hole 33 extends from the outer wall surface 32a on the module body 20 side to the inner wall surface 32b on the cover 31 side. The through-hole 33 is connected to each of the through-holes 12h of the module body 20 via a space. In other words, the through-holes 33, 12h, and 21h constitute a plurality of communication holes 49 that communicate with a plurality of internal spaces V of the module body 20. In other words, each of the through-holes 33, 12h, and 21h constitutes a part of the communication hole 49. The through-hole 33 corresponds to the exit of the communication hole 49 and has a circular shape in cross-section perpendicular to the Y-axis direction (see Figure 7). The bottom wall 32 can be said to have the through-hole 33 as part of the communication hole 49 that communicates with the internal spaces V formed between the plurality of electrodes of the module body 20 and which contain the electrolyte.

[0048] As shown in Figure 7, a pair of substantially frame-shaped connecting protrusions 34 are provided on the outer wall surface 32a of the bottom wall 32. The pair of connecting protrusions 34 are spaced apart in the X-axis direction at intervals corresponding to the connecting protrusions 27. The pair of connecting protrusions 34 connect the module body 20 and the pressure regulating valve 22, and also form a plurality (12 in this case) of flow channels 35 through which gas and electrolyte from each internal space V flows. The connecting protrusions 34 are joined to the connecting protrusions 27 of the module body 20. The connecting protrusions 34 have the shape and dimensions corresponding to the connecting protrusions 27. Therefore, the flow channels 35 have a rectangular shape in a cross-section perpendicular to the Y-axis direction. The connecting protrusions 34 are formed in a grid pattern when viewed from the Y-axis direction.

[0049] The module body 20 and the pressure regulating valve 22 are joined together, for example, by hot plate welding. Specifically, a hot plate is placed between the module body 20 and the pressure regulating valve 22, and the tips of the joining protrusions 27 and 34 are brought into contact with the hot plate. This causes the tips of the joining protrusions 27 and 34 to melt. Subsequently, while the joining protrusions 27 and 34 are melting, the tip of the joining protrusion 34 is pressed against the tip of the joining protrusion 27, thereby welding (joining) the joining protrusions 27 and 34 together. As a result, the module body 20 and the pressure regulating valve 22 are joined together.

[0050] As shown in Figures 5 and 6, the case 29 has an outer peripheral wall 36 and a partition wall 37 that project from the bottom wall 32 toward the cover 31. In this embodiment, the outer peripheral wall 36 and the partition wall 37 are integrally formed with the bottom wall 32. The outer peripheral wall 36 is erected on the edge of the inner wall surface 32b of the bottom wall 32 so as to surround a plurality (12 in this case) of valve bodies 30. Specifically, the outer peripheral wall 36 is formed around the entire circumference of the outer peripheral edge of the bottom wall 32 and constitutes the outer wall of the case 29. More specifically, the outer peripheral wall 36 is formed in a substantially rectangular frame shape along the outer peripheral edge of the bottom wall 32, which is formed in a substantially rectangular shape when viewed from the Y-axis direction.

[0051] The partition wall 37 is erected on the inner wall surface 32b of the bottom wall 32 so as to cover the side surface 30c of each valve body 30. In one example, the partition wall 37 forms a cylindrical housing space S1 in which each valve body 30 is housed. In this embodiment, the housing space S1 is formed by the partition wall 37 and a part of the outer peripheral wall 36 surrounding the side surface 30c of the valve body 30. Also in this embodiment, the partition wall 37 housing one valve body 30 and the partition wall 37 housing another valve body 30 located adjacent to that valve body 30 are formed integrally. Thus, partition walls 37 housing different valve bodies 30 may have a shared portion.

[0052] In this embodiment, with reference to the inner wall surface 32b of the bottom wall 32, the end face 36a of the outer peripheral wall 36 on the cover 31 side is higher in the Y-axis direction than the end face 37a of the partition wall 37 on the cover 31 side. Therefore, when the cover 31 is fixed to the case 29, the cover 31 is in contact with the end face 36a of the outer peripheral wall 36, while the cover 31 and the end face 37a of the partition wall 37 are spaced apart from each other. That is, a space S2 is formed between the cover 31 and the end face 37a of the partition wall 37. This space S2 functions as a flow path for gas and electrolyte that flows into the inside of the pressure regulating valve 22 from the internal space V.

[0053] The valve body 30 is housed in the housing space S1 within the housing 23 so as to close the through hole 33. Multiple valve bodies 30 are arranged in a line in the X-axis direction so as to close the corresponding through holes 33. The valve body 30 is a cylindrical member formed of an elastic material such as rubber. The valve body 30 has a first end face 30a that closes the through hole 33 on the inner wall surface 32b side of the bottom wall 32, a second end face 30b located on the opposite side of the first end face 30a, and a side surface 30c that connects the first end face 30a and the second end face 30b. The second end face 30b is the pressed surface that is pressed by the cover 31.

[0054] The valve body 30 is positioned so that its first end face 30a is pressed against the inner wall surface 32b of the bottom wall 32, thereby closing the through hole 33. The valve body 30 opens and closes the through hole 33 in accordance with the pressure in the internal space V. A gap G is provided between the side surface 30c of the valve body 30 and the inner wall surface 37b of the partition wall 37 or the inner wall surface 36b of the outer peripheral wall 36.

[0055] As shown in Figures 6 and 8, projections 38 for positioning the valve body 30 are formed on the inner wall surface 37b of the partition wall 37. The projections 38 protrude inward from the inner wall surface 37b of the partition wall 37. The projections 38 are provided along the entire inner wall surface 37b of the partition wall 37 in the direction (Y-axis direction) in which the central axis of the through hole 33 extends. The projections 38 are formed to contact the side surface 30c of the valve body 30. By contacting the valve body 30 with the projections 38, the center position of the valve body 30 and the central axis of the through hole 33 can coincide with each other. Such projections 38 can keep the displacement of the valve body 30 within a certain range. In this embodiment, a plurality of (in this case, six) projections 38 are formed at equal pitches around the central axis of the through hole 33.

[0056] As shown in Figure 8, in the containment space S1, a sealing portion 39, which is a projection that protrudes outward from the inner wall surface 32b of the bottom wall 32, is formed on the inner wall surface 32b of the bottom wall 32. That is, the sealing portion 39 is surrounded by a partition wall 37 when viewed from the Y-axis direction. Multiple sealing portions 39 are collectively surrounded by an outer peripheral wall 36. In one example, as described above, since one pressure regulating valve 22 is attached to two mounting areas 24, the multiple sealing portions 39 are arranged on one side and the other side from the center in the X-axis direction. The partition wall 37 surrounding the sealing portion 39 located on one side from the center in the X-axis direction and the partition wall 37 surrounding the sealing portion 39 located on the other side are spaced apart from each other at the center in the X-axis direction. In addition, the positions of adjacent sealing portions 39 in the Z-direction are offset from each other.

[0057] The sealing portion 39 closes the gap between the through hole 33 and the gap G by contacting the first end face 30a of the valve body 30, which is pressed against the sealing portion 39, thereby enabling it to be opened and closed. The sealing portion 39 is formed so as to surround the opening end of the through hole 33 on the inner wall surface 32b. The sealing portion 39 is formed in an annular shape along the edge of the through hole 33, with the central axis of the through hole 33 as the center. The sealing portion 39 is formed so as to surround the entire circumference of the through hole 33 without any gaps. As a result, the sealing portion 39 is in gap-free contact with the first end face 30a of the valve body 30, ensuring airtightness.

[0058] The cover 31 shown in Figures 5, 6, 9 to 12 is a member that closes the opening of the case 29. The cover 31 has a side wall 40 (second wall). The side wall 40 faces the bottom wall 32 of the case 29 in the Y-axis direction, with a plurality of valve bodies 30 in between. The side wall 40 and the bottom wall 32 constitute a pair of walls of the housing 23 that face each other in the Y-axis direction. The cover 31 is made of a resin such as PP, PPS, or modified PPE. In one example, the cover 31 may be manufactured by injection molding. When viewed from the Y-axis direction, the position of the outer peripheral edge of the cover 31 is approximately the same as the position of the outer peripheral edge of the case 29 (the outer edge of the outer peripheral wall 36).

[0059] The cover 31 is joined to the open end face of the case 29 by welding, for example, ultrasonic welding. Specifically, the outer peripheral edge of the side wall 40 is welded to the end face 36a of the outer peripheral wall 36 of the case 29. The side wall 40 is provided with a first hole 41 and a second hole 42 that penetrate the side wall 40 in the Y-axis direction. The first hole 41 and the second hole 42 open to the outer surface 40a of the side wall 40, communicating the inside and outside of the housing 23. The second hole 42 is located vertically above the first hole 41. The first hole 41 and the second hole 42 are arranged so as not to overlap with the valve body 30 when viewed from the Y-axis direction. The first hole 41 and the second hole 42 are arranged so as to be adjacent to the valve body 30 in the Z-axis direction when viewed from the Y-axis direction. The first hole 41 and the second hole 42 are arranged so as not to overlap with each other in the vertical direction (Z-axis direction). The first hole 41 and the second hole 42 are positioned spaced apart in the X-axis direction so that they do not overlap when viewed from the Z-axis direction.

[0060] 2nd hole 42 This is an exhaust port (discharge port) for exhausting (discharging) the gas inside the pressure regulating valve 22 to the outside of the pressure regulating valve 22. 1st hole 41 This is an outlet for discharging the electrolyte inside the pressure regulating valve 22 to the outside of the pressure regulating valve 22. 2nd hole 42 teeth, 1st hole 41 Because it is located more vertically upward, lighter gases such as hydrogen and oxygen generated in the module body 20 are more likely to be present than atmospheric gases. 2nd hole 42 It is exhausted from there. Meanwhile, the electrolyte 1st hole 41 It is discharged in a dripping manner. For example, the first hole 41 and the second hole 42 have an oval shape with the X-axis direction as the longitudinal direction in a cross section perpendicular to the Y-axis direction. The first hole 41 and the second hole 42 have the same shape as each other.

[0061] The side wall 40 is provided with a plurality (in this case, 6) of first holes 41 and a plurality (in this case, 6) of second holes 42. The plurality of first holes 41 are arranged in a row in the X-axis direction. The plurality of second holes 42 are arranged in a row in the X-axis direction. The plurality of first holes 41 and the plurality of second holes 42 are arranged alternately in the X-axis direction. Three first holes 41 and three second holes 42 are provided for each mounting area 24 (see Figure 4).

[0062] The outer surface 40a has a region in the center in the X-axis direction where the first hole 41 and the second hole 42 are not provided. This region corresponds to the region between the pair of mounting regions 24 on the outer peripheral surface 12r. In one example, identification information (not shown) is provided in this region. The identification information can be used for individual identification of the energy storage module 4. The identification information may be, for example, characters, symbols, barcodes, two-dimensional codes (QR code®), etc., that can be read by optical means. The identification information may be printed with ink or drawn with a laser or the like. The identification information may be printed on a sticker and affixed to the outer surface 40a.

[0063] The cover 31 has protrusions 43 (first protrusion), 44 (second protrusion), 45 (second protrusion), and 46 (second protrusion) provided on the outer surface 40a of the side wall 40. As an example, the cover 31 has a pair of protrusions 43, one protrusion 44, a pair of protrusions 45, and a plurality (in this case, 22) of protrusions 46. Each of the protrusions 43, 44, 45, and 46 is integrally formed with the side wall 40.

[0064] The projection 43 protrudes outward along the Y-axis from between the first hole 41 and the second hole 42 on the outer surface 40a. When viewed from the Y-axis direction, the projection 43 extends in the X-axis direction so as to partition the first hole 41 and the second hole 42 vertically (in the Z-axis direction). The projection 43 partitioning the first hole 41 and the second hole 42 vertically means that, as shown in Figure 10, the projection 43 extends in such a way that it intersects a virtual straight line m1 connecting the center of a certain first hole 41 and the center of the second hole 42 closest to that first hole 41. Here, the center of the first hole 41 is, for example, the centroid of the opening shape of the first hole 41 on the outer surface 40a. The center of the second hole 42 is, for example, the centroid of the opening shape of the second hole 42 on the outer surface 40a.

[0065] More preferably, the projection 43 extends in a direction intersecting the vertical direction (X-axis direction) as viewed from the Y-axis direction, blocking both a virtual straight line m2 connecting one end of the first hole 41 and one end of the second hole 42, and a virtual straight line m3 connecting the other end of the first hole 41 and the other end of the second hole 42. As viewed from the Y-axis direction, the first hole 41 is located vertically below the projection 43, and the second hole 42 is located vertically above the projection 43. One projection 43 is provided for each mounting area 24 (see Figure 4). The pair of projections 43 are spaced apart from each other in the X-axis direction.

[0066] The length L1 of the projection 43 in the X-axis direction is greater than or equal to the length L2 of the first hole 41 in the X-axis direction, and greater than or equal to the length L3 of the second hole 42 in the X-axis direction. The projection 43 extends so as to cover the entire upper side of the first hole 41 and the entire lower side of the second hole 42 when viewed from the Y-axis direction. In this embodiment, lengths L2 and L3 are equivalent to each other. The projection 43 is provided with a length corresponding to the entire X-axis direction of the mounting area 24. That is, length L1 is equivalent to the X-axis direction length of the mounting area 24. The projection 43 has a length L1 that can cover the entire upper side of the three first holes 41 and the entire lower side of the three second holes 42 provided in the mounting area 24.

[0067] The projection 44 is provided in a frame shape so as to surround all of the multiple first holes 41 and multiple second holes 42. The projection 44 is provided on the outer edge of the outer surface 40a of the side wall 40. The projection 44 includes a first side portion 44a, a second side portion 44b, and a pair of third side portions 44c.

[0068] The first side 44a and the second side 44b face each other in the Z-axis direction with the projection 43 in between. The first side 44a is positioned vertically below the projection 43 and extends in the X-axis direction. Viewed from the Y-axis direction, the first hole 41 is located closer to the first side 44a than to the projection 43. The second side 44b is positioned vertically above the projection 43 and extends in the X-axis direction. Viewed from the Y-axis direction, the second hole 42 is located closer to the second side 44b than to the projection 43.

[0069] The pair of third sides 44c face each other in the X-axis direction. The pair of third sides 44c extend in the Z-axis direction and connect the first side 44a and the second side 44b. The third sides 44c are connected to one end of the corresponding projection 43 in the X-axis direction.

[0070] The pair of projections 45 are positioned on both sides of the region in the central part of the outer surface 40a in the X-axis direction where the first hole 41 and the second hole 42 are not provided. The pair of projections 45 face each other in the X-axis direction. Each projection 45 extends vertically downward from the other end in the X-axis direction of the corresponding projection 43 and is connected to the first side portion 44a. Both projections 44 and 45 are formed to the same height as projection 43. Here, height refers to the height in the Y-axis direction when the outer surface 40a is the reference plane. The projections 43, 44, and 45 are formed so that the positions of their tips are aligned with each other in the Y-axis direction.

[0071] The projection 46 extends in the Z-axis direction and connects projections 43 and 44. Vertically below each projection 43, four projections 46 are arranged in the X-axis direction together with projection 45, connecting each projection 43 to the first side portion 44a. Vertically above each projection 43, five projections 46 are arranged in the X-axis direction, connecting each projection 43 to the second side portion 44b. The projections 46 are provided between adjacent first holes 41 and second holes 42 in the X-axis direction.

[0072] As shown in Figure 11, projections 45 and 46 are positioned offset from the multiple sealing portions 39 when viewed from the compression direction (Y-axis direction) of the valve body 30. That is, when viewed from the Y-axis direction, projections 45 and 46 extend in the Z-axis direction, passing between adjacent sealing portions 39 in the X-axis direction. In one example, it is not necessary for the entire sealing portion 39 protruding from the inner wall surface 32b to be offset from projections 45 and 46. At a minimum, it is sufficient that the portion of the sealing portion 39 that can contact the first end face 30a of the valve body 30 is offset from projections 45 and 46.

[0073] The height of projection 46 is lower than the heights of projections 43, 44, and 45. Here, height refers to the height in the Y-axis direction when the outer surface 40a is the reference plane. The tip of projection 46 is located closer to the outer surface 40a than the tips of projections 43, 44, and 45. Projection 46 is provided, for example, to reinforce the side wall 40. The height of projection 46 is set to the height required to reinforce the side wall 40.

[0074] The protrusions 43, 44, 45, and 46 are provided so as to divide the outer surface 40a into a grid pattern. The multiple regions of the outer surface 40a thus divided consist of a region with one first hole 41, a region with one second hole 42, and a region without the first hole 41 and the second hole 42. When viewed from the Y-axis direction, it can be said that the protrusions 43, 44, 45, and 46 are provided so as to surround the first hole 41 and the second hole 42, respectively.

[0075] As explained above, in the pressure regulating valve 22, when the pressure in the internal space V is lower than the set pressure, the through hole 33 is closed by the valve body 30 and the valve is maintained in a closed state. When the pressure in the internal space V rises to or above the set pressure, the valve body 30 elastically deforms so as to move away from the bottom wall 32, and the through hole 33 is released, resulting in an open state. As a result, gas from the internal space V flows through the gap G (containment space S1) to the space S2 formed between the partition wall 37 and the cover 31. At this time, electrolyte may also flow from the internal space V to space S2 along with the gas.

[0076] In the pressure regulating valve 22, a first hole 41 and a second hole 42 located vertically above the first hole 41 are provided on the outer surface 40a of the side wall 40 of the cover 31 of the housing 23. Therefore, the electrolyte is discharged by dripping from the first hole 41 located vertically below. On the other hand, gases such as hydrogen and oxygen generated in the module body 20 are lighter than air, so they are discharged from the second hole 42 located vertically above. In this way, the electrolyte is not discharged together with the gas from the same hole, so the electrolyte is less likely to splash. Furthermore, a projection 43 is provided on the outer surface 40a of the side wall 40, which protrudes outward from between the first hole 41 and the second hole 42 and extends to separate the first hole 41 and the second hole 42. In other words, the projection 43 is provided so as to be interposed between the discharge path of the electrolyte discharged from the first hole 41 and the discharge path of the gas discharged from the second hole 42. Therefore, even if gas is forcefully ejected from the second hole 42, it is blocked by the projection 43 and is unlikely to come into contact with the electrolyte discharged from the first hole 41. As a result, the scattering of the electrolyte by gas can be suppressed.

[0077] The length L1 of the projection 43 is greater than or equal to the length L2 of the first hole 41 and greater than or equal to the length L3 of the second hole 42. When viewed from the Y-axis direction, the projection 43 extends so as to completely cover the upper side of the first hole 41 and the lower side of the second hole 42. As a result, the gas discharged from the second hole 42 is less likely to come into contact with the electrolyte discharged from the first hole 41. Therefore, splashing of the electrolyte can be further suppressed.

[0078] The first hole 41 and the second hole 42 are positioned so as not to overlap each other in the vertical direction. As the distance between the first hole 41 and the second hole 42 increases, the gas discharged from the second hole 42 is further suppressed from coming into contact with the electrolyte discharged from the first hole 41.

[0079] The cover 31 of the housing 23 further has projections 44, 45, and 46, which are provided on the outer surface 40a of the side wall 40 so as to surround the first hole 41 and the second hole 42, respectively, together with projection 43. Projections 44, 45, and 46 are arranged to cooperate with projection 43 to surround the first hole 41 and the second hole 42, respectively. As a result, the gas discharged from the second hole 42 is less likely to spread to the surroundings. Therefore, the gas is further suppressed from coming into contact with the electrolyte discharged from the first hole 41.

[0080] Multiple through-holes 33 are arranged side by side in the X-axis direction. In contrast, if the second hole 42 were provided at only one location in the X-axis direction, the path to the second hole 42 would be longer depending on the through-hole 33. As a result, there is a risk that gas may be exhausted from the first hole 41 located along the way to the second hole 42. In the pressure regulating valve 22, not only are multiple through-holes 33 arranged side by side in the X-axis direction, but multiple second holes 42 are also arranged side by side in the X-axis direction. Therefore, the path from each through-hole 33 to the second hole 42 can be shortened. This suppresses the discharge of gas flowing in from each through-hole 33 through the first hole 41.

[0081] Multiple first holes 41 may be arranged side by side in the X-axis direction. As a result, the amount of electrolyte discharged from each first hole 41 is reduced compared to the case where only one first hole 41 is provided. Therefore, in an energy storage device 1 in which energy storage modules 4 are stacked vertically, short circuits between adjacent energy storage modules 4 through the electrolyte discharged from the pressure regulating valve 22 are suppressed.

[0082] The present invention is not limited to the embodiments described above.

[0083] For example, the height of projection 43 may be lower or higher than the height of projection 44. The projection 43 may not extend over the entire length corresponding to the X-axis direction of the mounting area 24, but may be provided one per first hole 41.

[0084] The length L1 of the projection 43 may be less than the length L2 of the first hole 41, and may also be less than the length L3 of the second hole 42. Even in this case, as long as the projection 43 is interposed between the first hole 41 and the second hole 42 when viewed from the Y-axis direction, at least a portion of the gas discharged from the second hole 42 can be blocked. This further suppresses the scattering of the electrolyte.

[0085] The first hole 41 and the second hole 42 may be arranged so as to overlap each other when viewed from the vertical direction. The outer surface 40a of the side wall 40 does not need to have projections 44, 45, and 46. The number of first holes 41 and second holes 42 may be one or more each.

[0086] The gist of this disclosure is as follows: [1] to [6]. [1] An energy storage module comprising a module body having an electrode stack including a plurality of stacked electrodes, and a pressure regulating valve attached to the module body, wherein the pressure regulating valve comprises a housing having a first wall with a communication hole that communicates with an internal space formed between the plurality of electrodes and containing an electrolyte, a second wall facing the first wall in a first direction intersecting the vertical direction, and a first projection provided on the second wall, and a valve body housed in the housing so as to close the communication hole, wherein the second wall is provided with a first hole that communicates the inside and outside of the housing and opens to the outer surface of the second wall, and a second hole that communicates the inside and outside of the housing and opens to the outer surface and is located vertically above the first hole, and the first projection protrudes outward along the first direction on the outer surface and extends so as to separate the first hole and the second hole when viewed from the first direction. [2] The energy storage module according to [1], wherein, as viewed from the first direction, the length of the first projection in a second direction intersecting the vertical direction is greater than or equal to the length of the first hole and the second hole in the second direction, and the first projection extends so as to cover the entire upper side of the first hole and the entire lower side of the second hole as viewed from the first direction. [3] The energy storage module according to [1] or [2], wherein the first hole and the second hole are arranged so as not to overlap each other in the vertical direction. [4] The energy storage module according to any one of [1] to [3], wherein the housing further has a plurality of second protrusions provided so as to surround the first hole and the second hole, respectively, together with the first protrusion. [5] The energy storage module according to any one of [1] to [4], wherein the internal spaces are formed in a plurality, the communication holes are arranged in a plurality in a third direction that intersects the vertical direction when viewed from the first direction and communicate with each of the plurality of internal spaces, and the second holes are arranged in a plurality in the third direction. [6] The energy storage module according to any one of [1] to [5], wherein the first holes are arranged in a row in a third direction that intersects the vertical direction when viewed from the first direction. [Explanation of Symbols]

[0087] 4... Energy storage module, 20... Module body, 22... Pressure regulating valve, 23... Housing, 30... Valve body, 32... Bottom wall (first wall), 33... Through hole (communication hole), 40... Side wall (second wall), 41... First hole, 42... Second hole, 43... Protrusion (first protrusion), 44, 45, 46... Protrusion (second protrusion), V... Internal space.

Claims

1. A power storage module comprising a module body having an electrode stack including a plurality of stacked electrodes, and a pressure regulating valve attached to the module body, The aforementioned pressure regulating valve is A housing having a first wall with a communication hole formed between the plurality of electrodes and communicating with an internal space containing an electrolyte, a second wall facing the first wall in a first direction intersecting the vertical direction, and a first projection provided on the second wall, The housing comprises a valve body housed within the housing so as to close the communication hole, The second wall is provided with a first hole that connects the inside and outside of the housing and opens to the outer surface of the second wall, and a second hole that connects the inside and outside of the housing and opens to the outer surface, and is located vertically above the first hole. The first projection protrudes outward along the first direction on the outer surface and extends so as to separate the first hole and the second hole when viewed from the first direction. Multiple internal spaces are formed, The aforementioned communication holes are arranged in a row in a third direction that intersects the vertical direction when viewed from the first direction, and communicate with each of the multiple internal spaces. The second holes are arranged in a row in the third direction. Energy storage module.

2. Viewed from the first direction, the length of the first projection in the second direction intersecting the vertical direction is greater than or equal to the length of the first hole and the second hole in the second direction. The first projection extends so as to completely cover the upper side of the first hole and the lower side of the second hole when viewed from a first direction. The energy storage module according to claim 1.

3. The first hole and the second hole are arranged so as not to overlap each other in the vertical direction. The energy storage module according to claim 1 or 2.

4. The housing further has a plurality of second protrusions provided on its outer surface so as to surround the first hole and the second hole, respectively, together with the first protrusion. The energy storage module according to claim 1 or 2.

5. The first holes are arranged in a row in a third direction that intersects the vertical direction when viewed from the first direction. The energy storage module according to claim 1 or 2.

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