Power storage module and power storage group

Abstract

The present application relates to a power storage module and a power storage group. A seamless annular metal member (300) includes a pair of first edge portions extending in a stacking direction, and a pair of second edge portions extending in a direction orthogonal to the stacking direction and connecting the pair of first edge portions to each other. Each of a plurality of power storage cells has a main surface of a rectangular shape composed of a pair of long sides and a pair of short sides as viewed in the stacking direction. Each of the pair of second edge portions is arranged in parallel with the pair of long sides as viewed in the stacking direction. A hole portion (321) that penetrates in the stacking direction is formed in at least one of the pair of second edge portions.

Description

Technical Field

[0001] This invention relates to energy storage modules and energy storage banks. Background Technology

[0002] Japanese Patent Application Publication No. 2011-134699 discloses the structure of a battery module. The battery module described in this publication includes battery cells, end plates, and a retaining strap. Multiple batteries are connected within the battery cells. End plates are provided at the ends of the battery cells. The retaining strap surrounds and secures the assembly of the battery cells and end plates. The retaining strap contracts upon thermal expansion, tightening the battery cells and end plates. A connecting portion is provided in the retaining strap to connect the two ends in a closed-loop manner.

[0003] When the constraint members of multiple energy storage cells have connecting parts, it is necessary to connect the constraint members. In the constraint members, the connecting parts become the weakest parts, and the constraint force of the multiple energy storage cells obtained by the constraint members is limited by the strength of the connecting parts. Summary of the Invention

[0004] The purpose of this invention is to provide a battery module and battery pack that can constrain multiple battery cells with a higher constraint force while improving the strength of the constraint members during connection operations without the need for constraint members.

[0005] A battery storage module according to a first aspect of the present invention comprises a plurality of stacked battery cells, a seamless annular metal member, and a first spacer. The seamless annular metal member holds the plurality of battery cells in a stacking direction. The first spacer is disposed between the seamless annular metal member and the plurality of battery cells in the stacking direction. The seamless annular metal member includes: a pair of first sides extending in the stacking direction; and a pair of second sides extending in a direction orthogonal to the stacking direction and connecting the pair of first sides to each other. Each of the plurality of battery cells has a main surface with a rectangular shape formed by a pair of long sides and a pair of short sides when viewed from the stacking direction. Each of the pair of second sides is disposed parallel to the pair of long sides when viewed from the stacking direction. A hole extending through in the stacking direction is formed in at least one of the pair of second sides.

[0006] A battery pack according to a second aspect of the present invention comprises a plurality of stacked battery cells, a housing, and a first spacer. The housing holds and houses the plurality of battery cells in a stacking direction. The first spacer is disposed between the housing and the plurality of battery cells in the stacking direction. The housing includes: a pair of first sides extending in the stacking direction; and a pair of second sides extending in a direction orthogonal to the stacking direction and connecting the pair of first sides to each other. Each of the plurality of battery cells has a main surface with a rectangular shape formed by a pair of long sides and a pair of short sides when viewed from the stacking direction. Each of the pair of second sides is disposed parallel to the pair of long sides when viewed from the stacking direction. A hole extending through in the stacking direction is formed in at least one of the pair of second sides.

[0007] The above and other objects, features, aspects and advantages of the invention will become apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings. Attached Figure Description

[0008] Figure 1 This is a perspective view showing the appearance of the energy storage module in Embodiment 1.

[0009] Figure 2 This is a perspective view showing the state of the energy storage module of Embodiment 1 with the top cover and seamless annular metal component removed.

[0010] Figure 3 It is a three-dimensional diagram showing the structure of a single battery cell.

[0011] Figure 4 It is a three-dimensional view showing the appearance of the side panel.

[0012] Figure 5 It is a three-dimensional view showing the appearance of a seamless ring-shaped metal component.

[0013] Figure 6 It is a top view showing the structure of a seamless ring-shaped metal component.

[0014] Figure 7 This is a perspective view showing the appearance of the first spacer.

[0015] Figure 8 It is a three-dimensional view showing the appearance of the top cover.

[0016] Figure 9 This is a front view showing a configuration where multiple battery cells are fitted with a pair of side plates.

[0017] Figure 10 It is a cross-sectional view showing the state in which multiple energy storage cells with a pair of side plates are inserted into a seamless annular metal component.

[0018] Figure 11 From Figure 10A cross-sectional view viewed from the XI-XI direction.

[0019] Figure 12 It is a cross-sectional view showing a state in which multiple energy storage cells are compressed in the stacking direction and a first spacer is inserted in the gap between the seamless annular metal member and the multiple energy storage cells.

[0020] Figure 13 This is a cross-sectional view showing the state where the cylinder has released its pressure on multiple battery cells.

[0021] Figure 14 From Figure 13 A cross-sectional view viewed in the direction of the arrow along line XIV-XIV.

[0022] Figure 15 It is a cross-sectional view showing a state in which busbars are mounted on multiple energy storage cells.

[0023] Figure 16 It is a cross-sectional view showing the state of the busbar plate with the top cover mounted on it.

[0024] Figure 17 This diagram shows the engagement relationship between the first spacer and the second spacer of the energy storage module in a modified embodiment of this invention.

[0025] Figure 18 This is a top view showing the structure of the energy storage unit in Embodiment 2.

[0026] Figure 19 It is a three-dimensional view showing the appearance of the casing.

[0027] Figure 20 It is a three-dimensional diagram showing the state in which multiple battery cells are housed inside the casing.

[0028] Figure 21 This is a cross-sectional view showing the state in which a first spacer is inserted in the gap between the casing and multiple battery cells.

[0029] Figure 22 It is a three-dimensional diagram showing the state in which busbars and top covers are mounted on multiple battery cells.

[0030] Figure 23 It is a three-dimensional view showing the state of the shell with the shell cover installed.

[0031] Figure 24 This is a perspective view showing the appearance of the first spacer of the energy storage group in the first modified example of this embodiment.

[0032] Figure 25 This is a perspective view showing the structure of the first protrusion of the first spacer of the energy storage group in the second variation of this embodiment.

[0033] Figure 26 This is a perspective view showing the structure of the first protrusion of the first spacer of the energy storage group in the third variation of this embodiment. Detailed Implementation

[0034] The embodiments of the present invention will be described below. Furthermore, sometimes the same or equivalent parts are labeled with the same reference numerals, and their description will not be repeated.

[0035] Furthermore, in the embodiments described below, when numbers, quantities, etc., are mentioned, the scope of the present invention is not necessarily limited to those numbers, quantities, etc., unless specifically stated otherwise. Additionally, in the embodiments described below, each constituent element is not necessarily essential to the present invention, unless specifically stated otherwise.

[0036] Furthermore, in this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a structure is included, it may or may not include other structures besides that structure. Additionally, the present invention is not necessarily limited to achieving all the effects mentioned in this embodiment.

[0037] In this specification, "battery" is not limited to lithium-ion batteries and may include other batteries such as nickel-metal hydride batteries. In this specification, "electrode" can be a general term for both positive and negative electrodes. Additionally, "electrode plate" can be a general term for both positive and negative electrode plates. "Current collector" can be a general term for both positive and negative current collector components.

[0038] In this specification, when the terms "energy storage cell", "energy storage module" and "energy storage group" are used, "energy storage cell", "energy storage module" and "energy storage group" are not limited to battery cells, battery modules and battery groups, and may include capacitor cells, etc.

[0039] (Implementation Method 1)

[0040] Figure 1 This is a perspective view showing the appearance of the energy storage module in Embodiment 1. Figure 2 This is a perspective view showing the state of the energy storage module of Embodiment 1 with the top cover and seamless annular metal component removed. Figure 3 It is a three-dimensional diagram showing the structure of a single battery cell.

[0041] like Figures 1-3 As shown, the energy storage module 10 of Embodiment 1 includes a plurality of stacked energy storage cells 100, a seamless annular metal member 300, and a first spacer 400. The energy storage module 10 also includes a pair of side plates 200, a busbar plate 500, a top cover 600, and a busbar 700. The energy storage module 10 is a so-called battery pack.

[0042] like Figure 2 and Figure 3 As shown, multiple battery cells 100 are stacked in a manner arranged along the Y-axis. This forms a stack of battery cells 100. Spacers (not shown) are sandwiched between the battery cells 100.

[0043] like Figure 3 As shown, the battery cell 100 includes electrode terminals 110, a frame, and a gas discharge valve 140. The frame consists of an outer body 120 with an opening 121 and a sealing plate 130 that seals the opening 121.

[0044] The frame is formed in a generally rectangular shape. Specifically, each of the multiple battery cells 100 has a main surface 122 that is rectangular in shape, formed by a pair of long sides 123 and a pair of short sides 124 when viewed from the Y-axis direction (stacked direction). Electrodes (not shown) and electrolyte are housed within the frame. The outer surface of the casing 120 may also be covered by an insulating film (not shown).

[0045] Electrode terminal 110 includes a positive terminal 111 and a negative terminal 112. Electrode terminal 110 is formed on sealing plate 130. Gas discharge valve 140 is formed on sealing plate 130 at a position between positive terminal 111 and negative terminal 112. Gas discharge valve 140 breaks when the pressure inside the frame reaches a threshold value. As a result, flammable gas inside the frame is discharged outside the frame.

[0046] like Figure 2 As shown, adjacent electrode terminals 110 in the Y-axis direction (stacked direction) are electrically connected to each other via busbar 700. Thus, multiple energy storage cells 100 are electrically connected in series or in parallel.

[0047] Figure 4 This is a three-dimensional view showing the appearance of the side panel. For example... Figure 2 and Figure 4 As shown, a pair of side plates 200 are configured to sandwich a plurality of energy storage cells 100 between each other in the width direction (X-axis direction) of the energy storage module 10.

[0048] Specifically, each pair of side panels 200 includes: a side wall portion 210 extending in the Y-axis direction (stack direction); a bottom plate portion 220 extending from the lower end of the side wall portion 210 to both sides in the width direction (X-axis direction); and a top plate portion 230 extending from the upper end of the side wall portion 210 to one side in the width direction (X-axis direction).

[0049] The sidewall portion 210 contacts the side of the outer casing 120 of each of the plurality of battery cells 100. The bottom plate portion 220 contacts the bottom surface of the outer casing 120 of each of the plurality of battery cells 100. The top plate portion 230 contacts the sealing plate 130 of each of the plurality of battery cells 100. The side plate 200 is formed of a resin with insulating and heat-resistant properties.

[0050] Figure 5 It is a three-dimensional view showing the appearance of a seamless ring-shaped metal component. Figure 6 This is a top view showing the structure of a seamless ring-shaped metal component. For example... Figure 5 and Figure 6 As shown, the seamless annular metal member 300 has a rectangular annular shape. Specifically, the seamless annular metal member 300 includes: a pair of first sides 310 extending in the Y-axis direction (stack direction); and a pair of second sides 320 extending in a width direction (X-axis direction) orthogonal to the Y-axis direction (stack direction) and connecting the pair of first sides 310 to each other. The thickness T2 of each pair of second sides 320 is thicker than the thickness T1 of each pair of first sides 310.

[0051] A hole 321 extending in the Y-axis direction (stack direction) is formed on at least one of a pair of second side portions 320. In this embodiment, three holes 321 are formed at intervals in the width direction (X-axis direction) of the second side portion 320 located on the side in the Y-axis direction (stack direction). That is, a plurality of holes 321 are formed at intervals in the extending direction of the second side portion 320. Furthermore, the number of holes 321 formed on one of the second side portions 320 is not limited to three, and may also be one.

[0052] The seamless annular metal component 300 is a jointless annular component. The seamless annular metal component 300 is formed of metals such as aluminum or steel.

[0053] Figure 7 This is a perspective view showing the appearance of the first spacer. For example... Figure 2 and Figure 7 As shown, the first spacer 400 includes: a first base 410 extending in the width direction (X-axis direction); and a plurality of first protrusions 420 extending in the upward and downward direction (Z-axis direction) from the first base 410. The plurality of first protrusions 420 are arranged with a gap 430 between them. In this embodiment, the first spacer 400 includes four first protrusions 420. Furthermore, the number of first protrusions 420 is not limited to four, and may be two or more.

[0054] A protrusion 440 is formed on the upper surface of the first base 410. In this embodiment, two protrusions 440 are disposed at both ends of the first base 410 in the width direction (X-axis direction). Furthermore, the number of protrusions 440 is not limited to two. Additionally, the protrusions 440 may not necessarily be provided.

[0055] The first spacer 400 is formed of a resin that has insulating and heat-resistant properties. Furthermore, the material of the first spacer 400 is not limited to resin; it can also be a metal such as aluminum or steel.

[0056] like Figure 2 As shown, the busbar plate 500 has a generally flat shape. In this embodiment, the busbar plate 500 is bent such that its two ends are positioned above the central portion in the width direction (X-axis direction). The busbar plate 500 is formed of a resin that has insulating and heat-resistant properties.

[0057] Figure 8 This is a three-dimensional drawing showing the appearance of the top cover. For example... Figure 1 and Figure 8 As shown, multiple functionally distinct spaces are formed between the top cover 600 and the busbar plate 500.

[0058] Specifically, a gas pipe region TG is formed in the center of the width direction (X-axis direction) to serve as a flow path for flammable gas discharged from the gas discharge valve 140. Wiring regions TL are formed on both sides of the gas pipe region TG in the width direction (X-axis direction) to accommodate wiring that is electrically connected to each of the plurality of battery cells 100. Busbar regions TB are formed on the outer side of each of the two wiring regions TL in the width direction (X-axis direction) to accommodate busbars 700.

[0059] In the top cover 600, the top surface 610 of the gas pipeline area TG and the wiring area TL is a flat surface, and the top surface 620 of the busbar area TB is a downwardly sloping surface. The top cover 600 is formed of a resin with insulating and heat-resistant properties.

[0060] Here, the manufacturing method of the energy storage module of this embodiment will be described. Figure 9 This is a front view showing a configuration where multiple battery cells are fitted together with a pair of side plates. For example... Figure 9 As shown, side plates 200 are fitted onto both sides of a plurality of stacked battery cells 100. In this state, the plurality of battery cells 100 are covered by a pair of side plates 200 on both sides, both ends of the top surface in the width direction (X-axis direction), and both ends of the bottom surface in the width direction (X-axis direction).

[0061] Figure 10 It is a cross-sectional view showing the state in which multiple energy storage cells with a pair of side plates are inserted into a seamless annular metal component. Figure 11 From Figure 10 A cross-sectional view viewed from the XI-XI direction.

[0062] like Figure 10 and Figure 11 As shown, a plurality of battery cells 100, each fitted with a pair of side plates 200, are inserted into a seamless annular metal member 300. In this state, as... Figures 9-11 As shown, each of the pair of second sides 320 of the seamless annular metal member 300, when viewed from the Y-axis direction (stacked direction), is arranged parallel to the pair of long sides 123 of the energy storage cell 100. Figure 10 As shown, a pair of first edges 310 of the seamless annular metal member 300 are mounted on the base plate portion 220 of a pair of side plates 200. Figure 11 As shown, a gap is formed between the seamless annular metal component 300 and the multiple energy storage cells 100 in the Y-axis direction (stacked direction).

[0063] Figure 12 This is a cross-sectional view showing a configuration in which multiple battery cells are compressed in a stacking direction, and a first spacer is inserted into the gap between the seamless annular metal member and the multiple battery cells. (Example) Figure 12 As shown, the multiple energy storage cells 100 are compressed by inserting a cylinder 1 from the outside into the central hole 321 of the three holes 321 in the width direction (X-axis direction), pressing the other of the two second side portions 320 between the cylinder 1 and the cylinder 1. Then, a first spacer 400 is inserted into the gap between the seamless annular metal member 300 in the Y-axis direction (stacked direction) and the multiple energy storage cells 100. Alternatively, the multiple energy storage cells 100 can be compressed by inserting the cylinder 1 from the outside into each of the three holes 321.

[0064] Figure 13 This is a cross-sectional view showing the state where the cylinder has released its pressure on multiple battery cells. Figure 14 From Figure 13 A cross-sectional view viewed in the direction of the arrow along line XIV-XIV. For example... Figure 13 and Figure 14 As shown, by pulling the cylinder 1 out of the hole 321, the compressed multiple energy storage cells 100 are stretched in the Y-axis direction (stacked direction) to restore their original shape, thereby pressing the first spacer 400 between the multiple energy storage cells 100 and the second side 320 of one of the pair of second side portions 320.

[0065] As a result, the seamless annular metal member 300 clamps multiple battery cells 100 in the Y-axis direction (stack direction). A first spacer 400 is disposed between the seamless annular metal member 300 and the multiple battery cells 100 in the Y-axis direction (stack direction). That is, the first spacer 400 is disposed on one side of the stacked multiple battery cells 100 in the Y-axis direction (stack direction). In this state, as... Figure 1 As shown, the three holes 321 of the seamless annular metal member 300 overlap with the three gaps 430 of the first spacer 400 when viewed from the Y-axis direction (stacked direction).

[0066] Figure 15 This is a cross-sectional view showing a configuration where busbars are mounted on multiple battery cells. For example... Figure 15 As shown, a busbar board 500 is mounted on a plurality of battery cells 100. Two through holes 510 are formed in the busbar board 500 for inserting protrusions 440 of the first spacer 400. The busbar board 500 is positioned by inserting the protrusions 440 into each of the two through holes 510. Wiring for detecting the voltage of the battery cells 100 is provided on the busbar board 500.

[0067] Figure 16 This is a cross-sectional view showing the state where a top cover is mounted on the busbar. For example... Figure 16 As shown, a top cover 600 is mounted on the busbar board 500. Through the above processes, the energy storage module 10 of this embodiment is manufactured.

[0068] In the energy storage module 10 of this embodiment, a seamless annular metal member 300 is fitted with a plurality of stacked energy storage cells 100, clamping the plurality of energy storage cells 100 in the Y-axis direction (stacked direction). At least one of a pair of second sides 320 of the seamless annular metal member 300 has a hole 321 that extends through in the Y-axis direction (stacked direction). As a result, the first spacer 400 can be inserted while pressing the plurality of energy storage cells 100 by means of a pressing clamp, i.e., a cylinder 1, inserted into the hole 321. In addition, since the constraint member of the plurality of energy storage cells 100, i.e., the seamless annular metal member 300, has no connecting portion, the shear strength of the constraint member can be improved without the need for connection work, and the plurality of energy storage cells 100 can be constrained with a high constraint force by inserting the first spacer 400.

[0069] In the energy storage module 10 of this embodiment, the hole 321 of the seamless annular metal member 300 overlaps with the gap 430 of the first spacer 400 when viewed from the Y-axis direction (stacked direction). Therefore, while pressing multiple energy storage cells 100 by the cylinder 1 inserted into the hole 321, the first spacer 400 can be inserted in the vertical direction (Z-axis direction) to avoid interference with the cylinder 1.

[0070] In the energy storage module 10 of this embodiment, a plurality of holes 321 are formed at intervals in the extending direction of the second side portion 320. As a result, a cylinder 1 can be inserted into each of the plurality of holes 321 to stably compress the plurality of energy storage cells 100.

[0071] In the energy storage module 10 of this embodiment, the thickness T2 of each pair of second sides 320 is thicker than the thickness T1 of each pair of first sides 310. As a result, the first sides 310 can be made thinner and lighter while ensuring the rigidity of the second sides 320 that exert the constraint force on the plurality of energy storage cells 100.

[0072] Here, a modified example of the energy storage module of this embodiment will be described. Figure 17 This diagram shows the engagement relationship between the first spacer and the second spacer of the energy storage module in a modified embodiment of this invention.

[0073] like Figure 17 As shown, the energy storage module in this modified embodiment further includes a second spacer 800 that engages with the first spacer 400. The second spacer 800 includes a second base 810 extending in the width direction (X-axis direction); and at least one second protrusion 820 extending from the second base 810 in the upward and downward direction (Z-axis direction). In this modified embodiment, the second spacer 800 includes three second protrusions 820. Furthermore, the number of second protrusions 820 is not limited to three; one or more is acceptable. The three second protrusions 820 are arranged with a gap 830 between them.

[0074] The second base 810 extends parallel to a pair of long sides 123 of the battery cell 100. A second protrusion 820 extends parallel to a pair of short sides 124 from the second base 810 and is located in the gap 430 of the first spacer 400. The first protrusion 420 of the first spacer 400 is located in the gap 830 of the second spacer 800. Figure 17 As shown, in the gap 430 of the first spacer 400, the cylinder 1 is inserted into the portion where the second protrusion 820 is not configured.

[0075] In the modified energy storage module of this embodiment, the gap in the Y-axis direction (stacked direction) between the plurality of energy storage cells 100 and the seamless annular metal member 300 is filled by the first spacer 400 and the second spacer 800, thereby stably constraining the plurality of energy storage cells 100.

[0076] (Implementation Method 2)

[0077] Hereinafter, the energy storage unit of Embodiment 2 will be described with reference to the accompanying drawings. In the energy storage unit of Embodiment 2, the constraint member is a shell, which is different from the energy storage module of Embodiment 1. Therefore, the structure that is the same as that of the energy storage module of Embodiment 1 will not be described again.

[0078] Figure 18 This is a top view showing the structure of the energy storage unit in Embodiment 2. Figure 18 The busbar plate, top cover, and housing cover are not shown in the diagram. Figure 18 As shown, the energy storage group 20 of Embodiment 2 includes a plurality of stacked energy storage cells 100, a housing 900, and a first spacer 400. The energy storage group 20 also includes a busbar plate 500, a top cover 600, and a busbar 700.

[0079] like Figure 18 As shown, multiple energy storage cells 100 are stacked in a manner arranged along the Y-axis. This forms a stack of energy storage cells 100. Isolators (not shown) are sandwiched between the energy storage cells 100. The multiple energy storage cells 100 are connected in series or parallel to ground via a busbar 700.

[0080] Figure 19 This is a three-dimensional view showing the appearance of the casing. For example... Figure 19 As shown, the housing 900 has four rectangular storage areas. Alternatively, the housing 900 may have only one storage area. Each storage area of ​​the housing 900 includes: a pair of first sides 910 extending in the Y-axis direction (stack direction); and a pair of second sides 920 extending in a width direction (X-axis direction) orthogonal to the Y-axis direction (stack direction) and connecting the pair of first sides 910 to each other. The thickness of each pair of second sides 920 is greater than the thickness of each pair of first sides 910.

[0081] A hole 921 extending in the Y-axis direction (stack direction) is formed on at least one of a pair of second side portions 920. In this embodiment, three holes 921 are formed at intervals in the width direction (X-axis direction) of the second side portion 920 located on the side in the Y-axis direction (stack direction). That is, a plurality of holes 921 are formed at intervals in the extending direction of the second side portion 920. Furthermore, the number of holes 921 formed on one of the second side portions 920 is not limited to three, and may also be one.

[0082] The housing 900 is made of a metal such as aluminum or steel. An adhesive for fixing the battery cells 100 is applied to the bottom surface 930 of the housing 900.

[0083] Here, the manufacturing method of the energy storage unit according to this embodiment will be described. Figure 20 This is a three-dimensional diagram showing a configuration where multiple battery cells are housed within a casing. For example... Figure 20 As shown, multiple stacked battery cells 100 are housed in various storage areas of the housing 900. In this state, each of the pair of second sides 920 of the housing 900 is arranged parallel to the pair of long sides 123 of the battery cells 100 when viewed from the Y-axis direction (stack direction). A gap is formed between the housing 900 and the multiple battery cells 100 in the Y-axis direction (stack direction).

[0084] Figure 21 This is a cross-sectional view showing the state in which the first spacer is inserted into the gap between the housing and the plurality of battery cells. Similar to Embodiment 1, the plurality of battery cells 100 are compressed by inserting the cylinder 1 from the outside into the central hole 921 of the three holes 921 located in the width direction (X-axis direction), pressing the other of the two second side portions 920 between the cylinder 1 and the cylinder 1. Then, the first spacer 400 is inserted into the gap between the housing 900 and the plurality of battery cells 100 in the Y-axis direction (stacked direction). Alternatively, the plurality of battery cells 100 can be compressed by inserting the cylinder 1 from the outside into each of the three holes 921.

[0085] By pulling the cylinder 1 out of the hole 921, the compressed multiple energy storage cells 100 are stretched in the Y-axis direction (stacked direction) to restore their original shape, thereby pressing the first spacer 400 between the multiple energy storage cells 100 and the second side 920 of one of the pair of second side portions 920.

[0086] As a result, Figure 21 As shown, the housing 900 holds a plurality of battery cells 100 in the Y-axis direction (stacked direction). A first spacer 400 is disposed between the housing 900 and the plurality of battery cells 100 in the Y-axis direction (stacked direction). That is, the first spacer 400 is disposed on one side of the stacked plurality of battery cells 100 in the Y-axis direction (stacked direction). The adhesive applied to the bottom surface 930 of the housing 900 cures after the first spacer 400 is disposed, thereby fixing the plurality of battery cells 100 and the first spacer 400 relative to the housing 900.

[0087] Figure 22 This is a three-dimensional diagram showing a configuration where multiple battery cells are equipped with busbars and top covers. For example... Figure 22 As shown, a busbar and a top cover 600 are mounted on multiple energy storage cells 100.

[0088] Figure 23 This is a three-dimensional view showing the casing with the casing cover installed. For example... Figure 23As shown, a housing cover 950 is mounted on the housing 900. In this state, the three holes 921 of the housing 900, when viewed from the Y-axis direction (stacked direction), overlap with the three gaps 430 of the first spacer 400, respectively. A connector 940 for electrical connection with a plurality of battery cells 100 is provided on the housing 900.

[0089] like Figure 18 As shown, each of the three holes 921 is blocked by the insert member 990. This seals the housing 900. The insert member 990 is attached to the holes 921 by welding or adhesive, etc. The insert member 990 is preferably made of the same material as the housing 900. In this case, it is possible to suppress the disruption of the sealing state of the housing 900 due to the difference in the coefficients of linear expansion between the housing 900 and the insert member 990.

[0090] In the energy storage assembly 20 of this embodiment, the housing 900 is fitted with a plurality of stacked energy storage cells 100, clamping the plurality of energy storage cells 100 in the Y-axis direction (stacked direction). At least one of a pair of second sides 920 of the housing 900 has a hole 921 that extends through in the Y-axis direction (stacked direction). As a result, the first spacer 400 can be inserted while pressing the plurality of energy storage cells 100 by means of a pressing clamp, i.e., a cylinder 1, inserted into the hole 921. In addition, since the constraint members of the plurality of energy storage cells 100, i.e., the first side 910 and the second side 920 of the housing 900, have no connecting portions, the shear strength of the constraint members can be improved without the need for connection work, and the plurality of energy storage cells 100 can be constrained with a high constraint force by inserting the first spacer 400.

[0091] In the energy storage unit 20 of this embodiment, the hole 921 of the housing 900 overlaps with the gap 430 of the first spacer 400 when viewed from the Y-axis direction (stacked direction). As a result, while pressing the multiple energy storage cells 100 by the cylinder 1 inserted into the hole 921, the first spacer 400 can be inserted in the vertical direction (Z-axis direction) to avoid interference with the cylinder 1.

[0092] In the energy storage module 10 of this embodiment, a plurality of holes 921 are formed at intervals in the extending direction of the second side portion 920. As a result, a cylinder 1 can be inserted into each of the plurality of holes 921 to stably compress the plurality of energy storage cells 100.

[0093] In the energy storage module 10 of this embodiment, the thickness of each pair of second sides 920 is greater than the thickness of each pair of first sides 910. As a result, the first sides 910 can be made thinner and lighter while ensuring the rigidity of the second sides 920 that exert the binding force on the plurality of energy storage cells 100.

[0094] Here, a modified version of the energy storage group of this embodiment will be described. Figure 24 This is a perspective view showing the appearance of the first spacer of the energy storage group in the first modified example of this embodiment.

[0095] like Figure 24 As shown, in the first modified embodiment of this invention, the first spacer 400a of the energy storage assembly has a protrusion 450 on one side of the surface in the Y-axis direction (stack direction) that abuts against the main surface 122. The protrusion 450 is smaller than the main surface 122. That is, when viewed from the Y-axis direction (stack direction), the protrusion 450 is located inside the edge of the main surface 122. By having the first spacer 400a have the protrusion 450, it is possible to stably constrain multiple energy storage cells 100 with a higher constraint force.

[0096] Figure 25 This is a perspective view showing the structure of the first protrusion of the first spacer of the energy storage group in the second modification of this embodiment. Figure 25 As shown, in the second variation of this embodiment, the first spacer 400b of the energy storage assembly has chamfered portions 422 formed at both ends of the front end face 421 of the first protrusion 420 in the Y-axis direction (stacked direction). This allows the first spacer 400b to be easily inserted between the housing 900 and the plurality of energy storage cells 100.

[0097] Figure 26 This is a perspective view showing the structure of the first protrusion of the first spacer of the energy storage group in the third modification of this embodiment. Figure 26 As shown, in the third variation of this embodiment, the first spacer 400c of the battery pack has a groove 423 extending in the width direction (X-axis direction) formed on the front end face 421 of the first protrusion 420. This allows the adhesive applied to the bottom surface 930 of the housing 900 to flow through the groove 423 to the outer side of the first spacer 400c in the width direction (X-axis direction), thus preventing the first spacer 400c from floating due to the adhesive.

[0098] Furthermore, the groove 423 can also extend in the Y-axis direction (stack direction). In this case, the resistance experienced by the first spacer 400c from the adhesive can be reduced when the multiple battery cells 100 are compressed and expanded.

[0099] The structures that can be combined with each other in the above embodiments can also be combined.

[0100] Embodiments of the present invention have been described, but should be considered as illustrative rather than restrictive in all respects. The scope of the invention is defined by the claims and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. An energy storage module, wherein, The energy storage module has the following features: Multiple stacked battery cells; A seamless annular metal component that holds the plurality of energy storage cells in the stacking direction; A pair of side plates, which are fitted onto both sides of the plurality of energy storage cells in a width direction orthogonal to the stacking direction; A first spacer is disposed in the stacking direction between the seamless annular metal member and the plurality of energy storage cells; The second spacer engages with the first spacer; Busbar plate, which is mounted on the plurality of energy storage cells; as well as Top cover, which is mounted on the busbar plate, The seamless annular metal member includes: a pair of first sides extending in the stacking direction; and a pair of second sides extending in a direction orthogonal to the stacking direction and connecting the pair of first sides to each other. Each of the plurality of battery cells has a main face that is rectangular in shape, consisting of a pair of long sides and a pair of short sides, when viewed from the stacking direction. Each of the pair of second sides is arranged parallel to the pair of long sides when viewed from the stacking direction. A hole extending through the lamination direction is formed in at least one of the pair of second edges. The first spacer includes: a first base extending parallel to the pair of long sides; and a plurality of first protrusions extending from the first base parallel to the pair of short sides. The plurality of first protrusions are arranged with gaps between them. The hole overlaps with the gap when viewed from the stacking direction. A protrusion for positioning the busbar plate is formed on the upper surface of the first base. The second spacer includes: a second base extending parallel to the pair of long sides; and at least one second protrusion extending from the second base parallel to the pair of short sides and located in the gap. The busbar plate is positioned by engaging with the protrusion of the first spacer. A plurality of spaces are formed between the top cover and the busbar, including a gas conduit area that serves as a flow path for flammable gases discharged from the plurality of battery cells and a wiring area that is configured with wiring electrically connected to each of the plurality of battery cells. The pair of side plates each includes: a sidewall portion extending in the stacking direction and contacting the side surfaces of each of the plurality of battery cells; a bottom plate portion extending from the lower end of the sidewall portion to both sides in the width direction and contacting the bottom surfaces of each of the plurality of battery cells and supporting the pair of first edges of the seamless annular metal member; and a top plate portion extending from the upper end of the sidewall portion to one side in the width direction and contacting the top surfaces of each of the plurality of battery cells. With the pair of side plates fitted onto both sides of the stacked plurality of battery cells in the width direction, and with a gap formed between the seamless annular metal member and the plurality of battery cells in the stacking direction, the plurality of battery cells are inserted into the seamless annular metal member. The second protrusion extends parallel to the pair of short sides from the second base and is located in the gap of the first spacer, and the first protrusion of the first spacer is located in the gap between the plurality of second protrusions of the second spacer.

2. The energy storage module according to claim 1, wherein, The holes are formed in a plurality of spaced-apart portions along the extension direction of the second side portion.

3. The energy storage module according to claim 1 or 2, wherein, The thickness of each of the pair of second sides is greater than the thickness of each of the pair of first sides.

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