Energy storage module

Abstract

This electricity storage module is provided with a first electricity storage device, a second electricity storage device, a first holder, a second holder and a reinforcement member. The first electricity storage device and the second electricity storage device are arranged in an orthogonal direction. The first holder has a first lateral plate. The second holder has a second lateral plate. The reinforcement member comprises a first reinforcement part, a second reinforcement part, and a first connection part. The first reinforcement part has a lateral plate groove into which the first lateral plate is fitted. The second reinforcement part has a lateral plate groove into which the second lateral plate is fitted. The first connection part connects the first reinforcement part and the second reinforcement part to each other, while being at least temporarily slidable with respect to at least one of the first reinforcement part and the second reinforcement part.

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage module. [Background technology]

[0002] Conventionally, a power storage module equipped with a plurality of cylindrical power storage devices (e.g., batteries) has been known (see, for example, Patent Document 1). In the power storage module disclosed in Patent Document 1, each power storage device has a cylindrical outer can, and each outer can houses a wound electrode body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-170613 Summary of the Invention [Problem to be solved by the invention]

[0004] Energy storage modules are sometimes used as power sources for vehicles and mobile devices. Therefore, it is desirable to reduce the weight of energy storage modules. One possible method for reducing the weight of an energy storage module is to encase multiple electrode assemblies in a common film exterior while maintaining individual sealing. This allows for an energy storage device having multiple electrode assemblies. In this case, the exterior cans that house each electrode assembly can be eliminated, thereby reducing the weight of the energy storage module. On the other hand, energy storage devices with a structure in which multiple electrode assemblies are sealed in a film exterior assembly are prone to significant deformation due to impacts, etc., due to the high flexibility of the film exterior assembly. Therefore, it is desirable to increase the holding strength of the energy storage device.

[0005] The present disclosure has been made in consideration of these circumstances, and one of its purposes is to provide a technology for increasing the holding strength of an energy storage device having a structure in which multiple electrode bodies are sealed in a film exterior body. [Means for solving the problem]

[0006] One aspect of the present disclosure is an energy storage module. The energy storage module includes a plurality of energy storage devices, a plurality of holders that hold the plurality of energy storage devices, and reinforcing members for the plurality of holders. The plurality of energy storage devices include a first energy storage device and a second energy storage device. The first energy storage device and the second energy storage device each include a plurality of cylindrical electrode assemblies, a plurality of housing sections that individually encase the plurality of electrode assemblies, and a film exterior body having sealing sections that seal each housing section and connect the plurality of housing sections to one another, and are aligned in an orthogonal direction that is perpendicular to the arrangement direction of the electrode assemblies and the axial direction of the electrode assemblies. The plurality of holders include a first holder and a second holder. The first holder has a first side plate extending in the arrangement direction and having a plurality of recesses into which the housing sections of the first energy storage devices fit. The second holder has a second side plate extending in the arrangement direction and having a plurality of recesses into which the housing sections of the second energy storage devices fit. The reinforcing member has a first reinforcing portion, a second reinforcing portion, and a first connecting portion. The first reinforcing portion extends in the arrangement direction and is aligned with the first side plate in the axial direction, and has a side plate groove into which the first side plate fits on its surface facing the first side plate. The second reinforcing portion extends in the arrangement direction and is aligned with the second side plate in the axial direction, and has a side plate groove into which the second side plate fits on its surface facing the second side plate. The first connecting portion connects the first reinforcing portion and the second reinforcing portion, and is at least temporarily slidable relative to at least one of the first reinforcing portion and the second reinforcing portion.

[0007] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to increase the holding strength of an electricity storage device having a structure in which a plurality of electrode bodies are sealed in a film exterior body. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of an electricity storage device included in an electricity storage module according to an embodiment. [Figure 2]Fig. 2(A) is a schematic diagram of the electricity storage device as viewed from the axial direction, and Fig. 2(B) is a schematic diagram of the electricity storage device as viewed from the perpendicular direction. [Figure 3] 3(A) to 3(C) are process diagrams of a method for manufacturing an electricity storage device. [Figure 4] 4(A) to 4(C) are process diagrams of a method for manufacturing an electricity storage device. [Figure 5] FIG. 1 is a perspective view of an electricity storage module according to an embodiment. [Figure 6] FIG. 2 is an exploded perspective view of the electricity storage module. [Figure 7] FIG. 3 is an enlarged perspective view showing first to third reinforcing parts. [Figure 8] Fig. 8(A) is a perspective view of the first to third reinforcing parts in an assembled state, and Fig. 8(B) is a perspective view of the first to third reinforcing parts in a state before they are assembled. [Figure 9] Fig. 9(A) is a perspective view of the power storage module group, and Fig. 9(B) is a side view of a portion of the power storage module group. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure will be described below with reference to preferred embodiments and drawings. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0011] FIG. 1 is a perspective view of an energy storage device 1 included in an energy storage module 100 according to an embodiment. FIG. 2(A) is a schematic diagram of the energy storage device 1 as viewed from an axial direction A. FIG. 2(B) is a schematic diagram of the energy storage device 1 as viewed from an orthogonal direction C. For ease of explanation, FIG. 2(B) also illustrates the inside of a film exterior body 4. The state before the film exterior body 4 is folded is illustrated by a dashed line. In this embodiment, the direction in which the spiral axis (the central axis of the cylinder) of the electrode body 2 extends is referred to as the axial direction A, the direction in which the multiple electrode bodies 2 are arranged is referred to as the arrangement direction B, and the direction orthogonal to the axial direction A and the arrangement direction B is referred to as the orthogonal direction C.

[0012] The power storage device 1 of this embodiment is, for example, a rechargeable secondary battery such as a lithium ion battery, a nickel-metal hydride battery, or a nickel-cadmium battery, or a capacitor such as an electric double layer capacitor. The power storage device 1 has a plurality of electrode bodies 2 and a film exterior body 4. The power storage device 1 of this embodiment has eight electrode bodies 2, but the number is not particularly limited as long as it is two or more.

[0013] Each electrode body 2 is cylindrical, and has a spirally wound structure in which a strip-shaped first electrode plate and a strip-shaped second electrode plate are stacked with an inter-electrode separator sandwiched between them. As an example, the first electrode plate is a negative electrode plate, and the second electrode plate is a positive electrode plate. A first electrode lead 8 is electrically connected to the first electrode plate. A second electrode lead 10 is electrically connected to the second electrode plate. For example, the first electrode lead 8 and the second electrode lead 10 are strip-shaped (rectangular and elongated in one direction), and one end of each is welded to the corresponding electrode plate. The multiple electrode bodies 2 are oriented so that the axial directions A of the electrode bodies 2 are parallel to each other, and are arranged at predetermined intervals in an arrangement direction B. The multiple electrode bodies 2 are wrapped in a common film exterior body 4.

[0014] The film exterior body 4 has a structure in which, for example, two laminate films are stacked. Each laminate film has a structure in which a thermoplastic resin sheet is laminated on both sides of a metal sheet, such as aluminum. The film exterior body 4 also has multiple storage sections 12 and a sealing section 14. The multiple storage sections 12 are arranged at predetermined intervals in the arrangement direction B. Each storage section 12 is cylindrical and individually encloses and stores each electrode body 2. Each storage section 12 is formed by a bag section provided in the film exterior body 4. The bag sections are portions of the two laminate films that are spaced apart from each other. Therefore, each storage section 12 protrudes from the sealing section 14 in accordance with the shape of the side surface of the electrode body 2. Each storage section 12 stores an electrolyte 16 together with the electrode body 2.

[0015] The sealing portion 14 surrounds the outer periphery of each storage portion 12 to seal it. The sealing portion 14 is formed, for example, by a welded portion of a thermoplastic resin sheet. The welded portion is obtained by subjecting the outer periphery of the bag portion of the film exterior body 4 to a thermocompression treatment, thereby welding the thermoplastic resin sheets of the two laminate films together. The sealing portion 14 seals each storage portion 12 and also connects the multiple storage portions 12 to one another.

[0016] The ends of the first electrode lead 8 and the second electrode lead 10 opposite to the end connected to the electrode body 2 protrude outside the film exterior body 4. The interface between each electrode lead and the film exterior body 4 is sealed with a known sealant. In this embodiment, the first electrode lead 8 and the second electrode lead 10 connected to each electrode body 2 protrude on opposite sides to each other in the axial direction A. Furthermore, each first electrode lead 8 protrudes on the same side.

[0017] The film exterior body 4 bends or curves between adjacent storage sections 12 and snakes in the arrangement direction B. That is, the film exterior body 4, and more specifically the sealing section 14, extends in a roughly zigzag pattern when viewed from the axial direction A. By folding the film exterior body 4 in a zigzag pattern, the spacing between the storage sections 12 in the arrangement direction B can be made narrower than in the state before folding, and therefore the length of the energy storage device 1 in the arrangement direction B can be shortened.

[0018] Furthermore, in this embodiment, the multiple storage sections 12 are arranged so that their centers are aligned on the same straight line when viewed from the axial direction A while the film exterior body 4 is in a serpentine state. This makes it possible to prevent the size of the energy storage device 1 in the orthogonal direction C from increasing, compared to when the multiple storage sections 12 are arranged so that their centers are offset in the orthogonal direction C. Furthermore, the zigzag-folded sealing section 14 is located inside the storage sections 12 in the orthogonal direction C. This makes it possible to prevent the size of the energy storage device 1 in the orthogonal direction C from increasing when the film exterior body 4 is folded. Note that, in the present disclosure, the centers of the multiple storage sections 12 do not necessarily have to be aligned on the same straight line.

[0019] The sealing portion 14 has a pair of first sides 14a and a pair of second sides 14b that surround the periphery of each storage portion 12. The pair of first sides 14a are aligned in the axial direction A, sandwiching each storage portion 12 therebetween, and seal the ends of each storage portion 12 in the axial direction A. In this embodiment, the first sides 14a extend linearly through the center of the storage portion 12 when viewed from the axial direction A. The pair of second sides 14b are aligned in a direction perpendicular to the axial direction A, sandwiching each storage portion 12 therebetween, and extend in the axial direction A to connect the pair of first sides 14a.

[0020] The two second sides 14b located between two adjacent storage sections 12 are connected to each other at a predetermined angle θ, i.e., non-linearly. The bending directions of the connection portions of the two second sides 14b are staggered at the multiple connection portions aligned in the arrangement direction B. As a result, the film exterior body 4 extends in a zigzag pattern in the arrangement direction B.

[0021] An example of a method for manufacturing the energy storage device 1 is shown below. FIGS. 3(A) to 3(C) and 4(A) to 4(C) are process diagrams of the method for manufacturing the energy storage device 1. First, as shown in FIG. 3(A), a first laminate film 20a is prepared. A plurality of semi-cylindrical depressions 18 are formed in advance in the first laminate film 20a. The depressions 18 are formed, for example, by subjecting the first laminate film 20a to a known process such as press working. An electrode body 2 is placed in each depression 18. A first electrode lead 8 and a second electrode lead 10 are connected to the electrode body 2 in advance. A sealant (not shown) is provided in the first electrode lead 8 and the second electrode lead 10.

[0022] 3(B), the second laminate film 20b is then superimposed on the first laminate film 20a to form the film exterior housing 4. The second laminate film 20b has semi-cylindrical depressions 18 formed in positions facing the depressions 18 in the first laminate film 20a. Therefore, by superimposing the first laminate film 20a and the second laminate film 20b, a bag portion, in other words, a storage portion 12, is formed by the pair of depressions 18. The method for forming the depressions 18 in the second laminate film 20b is the same as the method for forming the depressions 18 in the first laminate film 20a. With the electrode body 2 housed in the storage portion 12, the tip of the first electrode lead 8 and the tip of the second electrode lead 10 protrude outside the film exterior housing 4.

[0023] Next, as shown in FIG. 3(C), a thermocompression process is performed on a portion of the film exterior body 4 to form a welded portion 22. The portion of the film exterior body 4 that is not subjected to the thermocompression process becomes a non-welded portion 24. The non-welded portion 24 is arranged so as to connect each housing section 12 to the outside of the film exterior body 4. In the present embodiment, the non-welded portion 24 is provided so as to connect one of the four sides of each housing section 12 from which the first electrode lead 8 protrudes to the outside of the film exterior body 4. The remaining three sides of each housing section 12 are surrounded by the welded portion 22. The interface between the film exterior body 4 and the second electrode lead 10 is sealed with a sealant.

[0024] Next, as shown in FIG. 4(A), electrolyte 16 is poured into each housing section 12 through the non-welded sections 24. After the electrolyte 16 is poured, thermocompression bonding is also performed on the non-welded sections 24, as shown in FIG. 4(B). As a result, a sealing section 14 is formed that surrounds the entire periphery of each housing section 12. The interface between the film exterior body 4 and the first electrode lead 8 is sealed with a sealant. Next, as shown in FIG. 4(C), the film exterior body 4 is folded in a zigzag shape. Through the above steps, the electricity storage device 1 is obtained.

[0025] The manufacturing method of the energy storage device 1 is not limited to the above. For example, each electrode body 2 may be wrapped in a single laminate film having twice the length of the energy storage device 1, which is folded in half. Furthermore, when the required amount of electrolyte solution 16 is small, the step of injecting the electrolyte solution 16 shown in FIG. 4(A) can be omitted by pre-impregnating the inter-electrode separator with the electrolyte solution 16. In this case, in the thermocompression bonding step shown in FIG. 3(C), the entire periphery of each housing portion 12 is subjected to thermocompression bonding to form the sealing portion 14.

[0026] The energy storage device 1 is incorporated into an energy storage module 100 according to the present embodiment, which will be described below. FIG. 5 is a perspective view of the energy storage module 100 according to the embodiment. FIG. 6 is an exploded perspective view of the energy storage module 100. The energy storage module 100 includes a plurality of energy storage devices 1 and a plurality of holders 102. As an example, one energy storage device 1 and one holder 102 are combined to form one equipment unit 104, and the energy storage module 100 is made up of four equipment units 104. The number of equipment units 104 that make up the energy storage module 100 may be two or more. Furthermore, in the equipment unit 104, a plurality of energy storage devices 1 may be assembled to one holder 102.

[0027] The device units 104 are arranged in the orthogonal direction C. The orientation of each device unit 104 is determined so that the housing sections 12 of the energy storage devices 1 are aligned in the same direction. Two energy storage devices 1 adjacent to each other in the orthogonal direction C are arranged offset from each other in the arrangement direction B so that the axis of the electrode body 2 of one energy storage device 1 is positioned between the axes of two adjacent electrode bodies 2 of the other energy storage device 1. In other words, the housing section 12 of one energy storage device 1 fits into the gap between the two housing sections 12 of the other energy storage device 1. This makes it possible to reduce the dimension of the energy storage module 100 in the orthogonal direction C.

[0028] In each device unit 104, the energy storage device 1 is held by a holder 102. The holder 102 in this embodiment has a side plate 106 and a pair of protrusions 108. The side plate 106 is a rectangular plate extending in the arrangement direction B. The pair of protrusions 108 are rectangular plates protruding or extending in the orthogonal direction C from both ends of the side plate 106 in the arrangement direction B. In this disclosure, "protruding or extending in the orthogonal direction C" means that one end of a target member or part and the opposite end are offset in the orthogonal direction C. The pair of protrusions 108 face each other in the arrangement direction B. Therefore, the holder 102 has a generally U-shape that is long in the arrangement direction B. The holder 102 is oriented so that the main surface of the side plate 106 faces the orthogonal direction C and the main surfaces of the protrusions 108 face the arrangement direction B.

[0029] As an example, the holder 102 is made of a single plate material. The side plate 106 and the pair of protrusions 108 can be formed, for example, by bending both ends of a metal plate. Note that the holder 102 may be made of resin as long as a predetermined level of rigidity is obtained. Alternatively, the holder 102 may be formed by joining the side plate 106 and the protrusions 108, which are separate from each other. Examples of metals used for the holder 102 include aluminum, aluminum alloys, and steel. Examples of resins used for the holder 102 include thermoplastic resins such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and Noryl (registered trademark) resin (modified PPE); and fiber-reinforced plastics (FRP) including carbon fiber-reinforced plastics (CFRP) and glass fiber-reinforced plastics (GFRP).

[0030] The energy storage device 1 is surrounded on three sides in the arrangement direction B and the orthogonal direction C by the holder 102. The side plate 106 covers one surface of the energy storage device 1 in the orthogonal direction C. The pair of protrusions 108 cover both surfaces of the energy storage device 1 in the arrangement direction B. As an example, the side plate 106 is fixed to the opposing energy storage device 1 with an adhesive. The adhesive is preferably an insulating adhesive. An insulating sheet may be interposed between the energy storage device 1 and the holder 102.

[0031] The energy storage devices 1 are arranged in the orthogonal direction C with the holders 102 assembled thereto. That is, a plurality of equipment units 104 are arranged in the orthogonal direction C. At this time, the energy storage devices 1 are arranged so that the exposed surfaces not covered by the holders 102 face the same direction. With the energy storage devices 1 arranged, the exposed surface of each energy storage device 1 is covered by the side plate 106 of the adjacent equipment unit 104 and fixed with an adhesive. As a result, at least some of the energy storage devices 1 are sandwiched between the two side plates 106. Furthermore, at least some of the side plates 106 are sandwiched between the two energy storage devices 1.

[0032] Each protrusion 108 has a tip end 108a and a base end 108b. The base end 108b is interposed between the side plate 106 and the tip end 108a. The tip end 108a is offset from the base end 108b in a direction away from the power storage device 1. Therefore, the distance between the pair of protrusions 108 is wider on the tip end 108a side than on the base end 108b side. Each tip end 108a protrudes to a position where it overlaps with the base end 108b of the adjacent holder 102 when viewed from the arrangement direction B.

[0033] That is, when the multiple equipment units 104 are arranged in the orthogonal direction C, the side plates 106 and the pair of base ends 108b of one holder 102 enter between the pair of tip ends 108a of the other holder 102 in two adjacent holders 102. Then, a known joining process such as laser welding is performed on the overlapping portion between the tip ends 108a of one holder 102 and the base ends 108b of the other holder 102. As a result, the holders 102 are connected, and the multiple equipment units 104 are integrated.

[0034] The side plate 106 has a plurality of recesses 106a aligned in the arrangement direction B. Each recess 106a is groove-shaped and extends in the axial direction A. When the holder 102 is assembled to the energy storage device 1, each of the storage sections 12 of the energy storage device 1 facing the side plate 106 fits into each recess 106a. As a result, the side plate 106 extends along the curved surface of each storage section 12. This makes it possible to hold the energy storage device 1 more stably. In particular, it is possible to restrict displacement of the energy storage device 1 in the arrangement direction B.

[0035] Moreover, the side plate 106 of this embodiment is a corrugated plate with repeated concave and convex portions in the arrangement direction B. That is, when viewed from one main surface side, a plurality of concave portions 106a and a plurality of convex portions 106b are alternately arranged in the arrangement direction B. In this embodiment, when viewed from the main surface side facing the energy storage device 1 in each device unit 104, the portions curved in a direction away from the energy storage device 1 are called the concave portions 106a, and the portions curved in a direction toward the energy storage device 1 are called the convex portions 106b.

[0036] Therefore, the accommodation sections 12 of the energy storage devices 1 arranged on both sides of the side plate 106 can be fitted into the side plate 106. Specifically, when the side plate 106 is viewed from one main surface, the accommodation sections 12 of one energy storage device 1 are fitted into the recesses 106a and the protrusions 106b, respectively. Furthermore, the accommodation sections 12 of the other energy storage device 1 are fitted into the protrusions 106b (which appear as recesses when viewed from the opposite side) from the back surface side. This can further improve the stability of each energy storage device 1 in the energy storage module 100. The side plate 106 may be made of a plate material that is thicker than a corrugated plate and has a plurality of recesses arranged in the arrangement direction B on both sides.

[0037] The equipment unit 104 located at one end in the orthogonal direction C has no other equipment units 104 on the exposed surface side. Therefore, an end holder 110 is attached to the exposed surface of the energy storage device 1 in the equipment unit 104. The end holder 110, as an example, has the same shape as the holder 102, except that the protrusion 108 does not have the tip portion 108a.

[0038] Furthermore, a plurality of through holes 112 are provided in the side plate 106 and the pair of protrusions 108 of the present embodiment. The plurality of through holes 112 provided in the side plate 106 penetrate the side plate 106 in the plate thickness direction of the side plate 106. The plurality of through holes 112 are arranged in a matrix. Similarly, the plurality of through holes 112 provided in each protrusion 108 penetrate the protrusion 108 in the plate thickness direction of the protrusion 108. The plurality of through holes 112 are arranged in a matrix. By providing the through holes 112, it is possible to reduce the weight of the energy storage module 100.

[0039] The energy storage module 100 also includes a reinforcing member 114. The reinforcing member 114 is a member that fits into the multiple holders 102 to increase the rigidity of the multiple holders 102. The reinforcing member 114 has multiple reinforcing portions that extend in the arrangement direction B and are aligned with the side plates 106 in the axial direction A. Each reinforcing portion has a side plate groove 120 on the surface facing the side plate 106, into which the side plate 106 fits. The reinforcing member 114 also has a connecting portion that connects any two adjacent reinforcing portions. The connecting portion is connected to at least one of the two reinforcing portions so as to be slidable at least temporarily. The reinforcing member 114 is fitted into each holder 102 when the energy storage devices 1 held by the holders 102 are arranged in the orthogonal direction C and adjacent holders 102 are connected. Note that the holders 102 may be attached to the energy storage devices 1 after the reinforcing portions are fitted into the holders 102. The reinforcing member 114 will be described in detail below.

[0040] The multiple power storage devices 1 include a first power storage device 1-1 and a second power storage device 1-2. The first power storage device 1-1 and the second power storage device 1-2 are aligned in the orthogonal direction C. The multiple holders 102 include a first holder 102-1 and a second holder 102-2. The first holder 102-1 has a first side plate 106-1 and a first protrusion 108-1, and together with the first power storage device 1-1, forms an equipment unit 104. The second holder 102-2 has a second side plate 106-2 and a second protrusion 108-2, and together with the second power storage device 1-2, forms an equipment unit 104.

[0041] In this embodiment, the multiple power storage devices 1 further include a third power storage device 1-3 and a fourth power storage device 1-4. The first power storage device 1-1, the second power storage device 1-2, the third power storage device 1-3, and the fourth power storage device 1-4 are arranged in this order in the orthogonal direction C. The multiple holders 102 also include a third holder 102-3 and a fourth holder 102-4. The third holder 102-3 has a third side plate 106-3 and a third protrusion 108-3, and together with the third power storage device 1-3, forms an equipment unit 104. The fourth holder 102-4 has a fourth side plate 106-4 and a fourth protrusion 108-4, and together with the fourth power storage device 1-4, forms an equipment unit 104.

[0042] In the energy storage module 100 of the present embodiment, the first energy storage device 1-1 is in contact with the end holder 110, but there are no particular limitations on the arrangement of the first energy storage device 1-1 within the energy storage module 100. For ease of explanation, the side plate and protruding portion of the end holder 110 will be referred to as a fifth side plate 106-5 and a fifth protruding portion 108-5 below.

[0043] The reinforcing member 114 has a first reinforcing portion 116-1 to a tenth reinforcing portion 116-10. The first reinforcing portion 116-1 to the tenth reinforcing portion 116-10 are each a substantially flat rod-shaped member extending in the arrangement direction B. The first reinforcing portion 116-1 and the sixth reinforcing portion 116-6 are arranged side by side in the axial direction A, sandwiching the first side plate 106-1 therebetween. The second reinforcing portion 116-2 and the seventh reinforcing portion 116-7 are arranged side by side in the axial direction A, sandwiching the second side plate 106-2 therebetween. The third reinforcing portion 116-3 and the eighth reinforcing portion 116-8 are arranged side by side in the axial direction A, sandwiching the third side plate 106-3 therebetween. The fourth reinforcing portion 116-4 and the ninth reinforcing portion 116-9 are arranged side by side in the axial direction A, sandwiching the fourth side plate 106-4 therebetween. The fifth reinforcing portion 116-5 and the tenth reinforcing portion 116-10 are arranged side by side in the axial direction A with the fifth side plate 106-5 sandwiched therebetween.

[0044] Fig. 7 is an enlarged perspective view of the first reinforcing portion 116-1 to the third reinforcing portion 116-3. As shown in Fig. 7, the first reinforcing portion 116-1 has a side plate groove 120 on the surface facing the first side plate 106-1, into which the first side plate 106-1 fits. The edge of the first side plate 106-1 in the axial direction A fits into the side plate groove 120. Since the first side plate 106-1 of this embodiment is a corrugated plate, the side plate groove 120 is wavy.

[0045] The first reinforcing portion 116-1 has, on its surface facing the first side plate 106-1, protrusion grooves 122 into which the first protrusion 108-1 and the second protrusion 108-2 fit. The protrusion grooves 122 extend in the perpendicular direction C from both ends of the side plate groove 120 in the arrangement direction B. The edges of the first protrusion 108-1 and the second protrusion 108-2 in the axial direction A fit into the protrusion grooves 122. Similarly, the second reinforcing portion 116-2 has, on its surface facing the second side plate 106-2, the side plate groove 120 into which the second side plate 106-2 fits, and protrusion grooves 122 into which the second protrusion 108-2 and the third protrusion 108-3 fit, The third reinforcing portion 116-3 has, on its surface facing the third side plate 106-3, a side plate groove 120 into which the third side plate 106-3 fits, and protrusion grooves 122 into which the third protrusion 108-3 and the fourth protrusion 108-4 fit.

[0046] Although not shown, the fourth reinforcing portion 116-4 has, on its surface facing the fourth side plate 106-4, a side plate groove 120 into which the fourth side plate 106-4 fits and a protrusion groove 122 into which the fourth protrusion 108-4 fits. The fifth reinforcing portion 116-5 has, on its surface facing the fifth side plate 106-5, a side plate groove 120 into which the fifth side plate 106-5 fits and a protrusion groove 122 into which the fifth protrusion 108-5 and the first protrusion 108-1 fit. Furthermore, as shown in FIG. 6, the sixth reinforcing portion 116-6 to the tenth reinforcing portion 116-10 each have a side plate groove 120 and a protrusion groove 122 on their surfaces facing the respective side plates 106.

[0047] The rigidity of each holder (first holder 102-1 to fourth holder 102-4 and end holder 110) can be increased by fitting the edge of the side plate 106 into the side plate groove 120 of each reinforcing part. Furthermore, the rigidity of each holder can be further increased by fitting the edge of the protrusion 108 into the protrusion groove 122. Furthermore, in this embodiment, the side plate groove 120 and the protrusion groove 122 are connected to each other. This configuration allows the corners, which are the connection portions between the side plate 106 and the protrusion 108 of each holder, to be housed in the grooves. As a result, each holder can be held more firmly.

[0048] The protrusion grooves 122 do not have to be connected to the side plate grooves 120, and do not have to be provided in each reinforcing portion. Furthermore, the dimensions of each protrusion 108 in the axial direction A of the present embodiment are uniform. Therefore, two protrusions 108 fit into at least a portion of the protrusion grooves 122. Specifically, of two holders 102 adjacent to each other in the orthogonal direction C, a tip end 108a of one holder 102 fits into a base end 108b of the other holder 102.

[0049] However, the protrusions 108 and the protrusion grooves 122 are not limited to this configuration. For example, the tip 108a of each protrusion 108 may have both ends or one end in the axial direction A notched. With this configuration, it is possible to have a single protrusion 108 that fits into the protrusion groove 122. This allows the shape of the groove provided in the reinforcing portion to be consistent regardless of the position of the holder 102 relative to the energy storage module 100, that is, whether the holder 102 is positioned at an end in the orthogonal direction C or the center of the holder 102 in the orthogonal direction C. The dimension in the axial direction A of the tip 108a with the end in the axial direction A notched is, for example, equal to the distance between the two reinforcing portions that sandwich the holder 102 in the axial direction A.

[0050] The reinforcing member 114 also has a first connecting portion 124 and a second connecting portion 126. The first connecting portion 124 and the second connecting portion 126 are both generally flat rod-shaped and extend in the orthogonal direction C. Fig. 8(A) is a perspective view of the first reinforcing portion 116-1 to the third reinforcing portion 116-3 in an assembled state. Fig. 8(B) is a perspective view of the first reinforcing portion 116-1 to the third reinforcing portion 116-3 in a state before they are assembled.

[0051] The first connecting portion 124 is a portion that connects the first reinforcing portion 116-1 and the second reinforcing portion 116-2. The reinforcing member 114 of this embodiment has a plurality of first connecting portions 124 that are aligned in the arrangement direction B between the first reinforcing portion 116-1 and the second reinforcing portion 116-2. Each first connecting portion 124 extends in the orthogonal direction C, with one end connected to the first reinforcing portion 116-1 and the other end connected to the second reinforcing portion 116-2. Furthermore, each first connecting portion 124 is connected to at least one of the first reinforcing portion 116-1 and the second reinforcing portion 116-2 in a manner that allows it to slide at least temporarily.

[0052] The first connecting portions 124 in this embodiment are formed from part of the member that constitutes the second reinforcing portion 116-2. Each first connecting portion 124 extends from the second reinforcing portion 116-2 toward the first reinforcing portion 116-1. The first reinforcing portion 116-1 has a recess 128 on its surface facing away from the first side plate 106-1, into which a portion of the first connecting portion 124 slidably fits. The recess 128 constitutes a sliding mechanism for the first connecting portion 124. The width of the inner circumferential surface of the recess 128 (the dimension in the arrangement direction B) is set larger than the width of a cross section of the first connecting portion 124 perpendicular to the protruding direction. The tip of the first connecting portion 124 extending from the second reinforcing portion 116-2 rests on the first reinforcing portion 116-1 and fits into the recess 128. As a result, a gap is formed between the recess 128 and the portion of the first connecting portion 124 that is accommodated in the recess 128 in the arrangement direction B, and the first connecting portion 124 is slidably connected to the first reinforcing portion 116-1. The first connecting portion 124 is slidable relative to the first reinforcing portion 116-1 in the protruding direction of the first connecting portion 124. As will be described later, the bottom surface of the recess 128 may be located closer to the power storage device 1 in the axial direction A than the bottom surface of the mounting portion 134 that is provided on the first reinforcing portion 116-1. The step between these two bottom surfaces forms a side wall of the recess 128 in the orthogonal direction C. In this case, a gap may be formed between the recess 128 and the portion (tip) of the first connecting portion 124 that is accommodated in the recess 128 in the orthogonal direction C. This configuration also allows the first connecting portion 124 to be slidably connected to the first reinforcing portion 116-1. The side wall may be a surface perpendicular to the bottom surface of the recess 128, or may be an inclined or curved surface.

[0053] Connecting the first reinforcing portion 116-1 and the second reinforcing portion 116-2 by the first connecting portion 124 makes it possible to restrict relative displacement between the first reinforcing portion 116-1 and the second reinforcing portion 116-2. In particular, displacement in the arrangement direction B can be restricted. This increases the rigidity of the energy storage module 100. Furthermore, the first connecting portion 124 is slidably connected to the first reinforcing portion 116-1. Therefore, the distance between the side plate groove 120 of the first reinforcing portion 116-1 and the side plate groove 120 of the second reinforcing portion 116-2 can be flexibly changed depending on the distance between the first side plate 106-1 and the second side plate 106-2.

[0054] It is sufficient that the first connecting portion 124 is slidable relative to the first reinforcing portion 116-1 at least until the fitting of each reinforcing portion into each side plate 106 is completed (i.e., at least temporarily). Therefore, the first connecting portion 124 and the first reinforcing portion 116-1 may be fixed by adhesive or the like after each reinforcing portion is fitted into each side plate 106. This makes it possible to more firmly restrict relative displacement between the first reinforcing portion 116-1 and the second reinforcing portion 116-2, thereby further increasing the rigidity of the energy storage module 100. Note that even if the first connecting portion 124 and the first reinforcing portion 116-1 are not fixed, it is possible to restrict relative displacement between the first reinforcing portion 116-1 and the second reinforcing portion 116-2 to some extent.

[0055] Furthermore, the first connecting portion 124 may be configured as part of the member that constitutes the first reinforcing portion 116-1, and may be slidably connected to the second reinforcing portion 116-2. Alternatively, the first connecting portion 124 may be slidably connected to both the first reinforcing portion 116-1 and the second reinforcing portion 116-2. When the first connecting portion 124 is slidably connected to both the first reinforcing portion 116-1 and the second reinforcing portion 116-2, it is preferable to fix the first connecting portion 124 to at least one of the first reinforcing portion 116-1 and the second reinforcing portion 116-2 after fitting each reinforcing portion into each side plate 106.

[0056] The second connection portion 126 is a portion that connects the second reinforcement portion 116-2 and the third reinforcement portion 116-3. The reinforcement member 114 of this embodiment has a plurality of second connection portions 126 that are aligned in the arrangement direction B between the second reinforcement portion 116-2 and the third reinforcement portion 116-3. Each second connection portion 126 extends in the orthogonal direction C, with one end connected to the second reinforcement portion 116-2 and the other end connected to the third reinforcement portion 116-3. Furthermore, each second connection portion 126 is connected to at least one of the second reinforcement portion 116-2 and the third reinforcement portion 116-3 in a manner that allows it to slide at least temporarily.

[0057] The second connection portion 126 in this embodiment is formed from a part of the member that constitutes the second reinforcing portion 116-2. Each second connection portion 126 extends from the second reinforcing portion 116-2 toward the third reinforcing portion 116-3. The third reinforcing portion 116-3 has a recess 130, into which a portion of the second connection portion 126 slidably fits, on a surface facing away from the third side plate 106-3. The recess 130 constitutes a sliding mechanism for the second connection portion 126. The width of the inner circumferential surface of the recess 130 (the dimension in the arrangement direction B) is set larger than the width of a cross section of the second connection portion 126 perpendicular to the protruding direction. The tip of the second connection portion 126 extending from the second reinforcing portion 116-2 rests on the third reinforcing portion 116-3 and fits into the recess 130. As a result, a gap is formed between the recess 130 and the portion of the second connection portion 126 that is accommodated in the recess 130 in the arrangement direction B, and the second connection portion 126 is slidably connected to the third reinforcement portion 116-3. The second connection portion 126 is slidable relative to the third reinforcement portion 116-3 in the protruding direction of the second connection portion 126. As will be described later, the bottom surface of the recess 130 may be located closer to the energy storage device 1 in the axial direction A than the bottom surface of a mounting portion 134 provided on the third reinforcement portion 116-3. The step between these two bottom surfaces forms a side wall of the recess 130 in the orthogonal direction C. In this case, a gap may be formed between the recess 130 and the portion of the second connection portion 126 that is accommodated in the recess 130 (the tip surface) in the orthogonal direction C. This configuration also allows the second connection portion 126 to be slidably connected to the third reinforcement portion 116-3. The side wall may be a surface perpendicular to the bottom surface of the recess 130, or may be an inclined or curved surface.

[0058] Connecting the second reinforcing portion 116-2 and the third reinforcing portion 116-3 by the second connecting portion 126 makes it possible to restrict relative displacement between the second reinforcing portion 116-2 and the third reinforcing portion 116-3. In particular, displacement in the arrangement direction B can be restricted. This increases the rigidity of the energy storage module 100. Furthermore, the second connecting portion 126 is slidably connected to the third reinforcing portion 116-3. Therefore, the distance between the side plate groove 120 of the second reinforcing portion 116-2 and the side plate groove 120 of the third reinforcing portion 116-3 can be flexibly changed depending on the distance between the second side plate 106-2 and the third side plate 106-3.

[0059] It is sufficient that the second connection portion 126 is slidable relative to the third reinforcing portion 116-3 at least until the fitting of each reinforcing portion into each side plate 106 is completed. Therefore, the second connection portion 126 and the third reinforcing portion 116-3 may be fixed by adhesive or the like after each reinforcing portion is fitted into each side plate 106. This makes it possible to more firmly restrict the relative displacement between the second reinforcing portion 116-2 and the third reinforcing portion 116-3, thereby further increasing the rigidity of the energy storage module 100. Note that even if the second connection portion 126 and the third reinforcing portion 116-3 are not fixed, it is possible to restrict the relative displacement between the second reinforcing portion 116-2 and the third reinforcing portion 116-3 to some extent.

[0060] Furthermore, the second connecting portion 126 may be configured as part of a member constituting the third reinforcing portion 116-3 and may be slidably connected to the second reinforcing portion 116-2. Alternatively, the second connecting portion 126 may be slidably connected to both the second reinforcing portion 116-2 and the third reinforcing portion 116-3. When the second connecting portion 126 is slidably connected to both the second reinforcing portion 116-2 and the third reinforcing portion 116-3, it is preferable to fix the second connecting portion 126 to at least one of the second reinforcing portion 116-2 and the third reinforcing portion 116-3 after fitting each reinforcing portion into each side plate 106.

[0061] In the present disclosure, "composed of a part of the member constituting the second reinforcing portion 116-2" does not mean that the second reinforcing portion 116-2 and each connecting portion, which are originally separate bodies, are fixed to each other by a known fixing method such as welding or adhesive, but rather that the second reinforcing portion 116-2 and each connecting portion are fabricated into a single member by a known molding process such as press working or injection molding. In other words, a part of the member constituting the second reinforcing portion 116-2 extends toward the first reinforcing portion 116-1 to form the first connecting portion 124, and a part of the member extends toward the third reinforcing portion 116-3 to form the second connecting portion 126.

[0062] 5 to 8(B), the energy storage module 100 of this embodiment includes a bus bar 132 that electrically connects the plurality of electrode assemblies 2. The reinforcing member 114 is insulating and has a mounting portion 134 for the bus bar 132. That is, the reinforcing member 114 also serves as an insulating plate that supports the bus bar 132. The bus bar 132 is made of a conductive material such as copper or aluminum. The reinforcing member 114 is made of, for example, an insulating resin. Examples of resins that can be used to form the reinforcing member 114 include thermoplastic resins such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and Noryl (registered trademark) resin (modified PPE); and fiber-reinforced plastics (FRP) including carbon fiber-reinforced plastics (CFRP) and glass fiber-reinforced plastics (GFRP).

[0063] The mounting portion 134 is provided on a surface of a predetermined reinforcing portion facing away from the holder 102. In the present embodiment, the mounting portion 134 is provided on the first reinforcing portion 116-1, the second reinforcing portion 116-2, the third reinforcing portion 116-3, the sixth reinforcing portion 116-6, and the eighth reinforcing portion 116-8. Each mounting portion 134 is configured, for example, as a groove-like recess that matches the shape of the bus bar 132. As an example, the depth of the mounting portion 134 is greater than the thickness of the bus bar 132. With this configuration, when the energy storage module 100 abuts against surrounding components, the bus bar 132 can be prevented from abutting against surrounding components. Note that the thickness of the bus bar 132 may be greater than the depth of the mounting portion 134. In this case, the portion of the bus bar 132 that protrudes from the mounting portion 134 may be covered with an insulating cap (not shown). Furthermore, the bottom surface of recess 128 into which first connecting portion 124 fits and recess 130 into which second connecting portion 126 fits may be farther from bus bar 132 in axial direction A than the bottom surface of the recess constituting mounting portion 134. In other words, recesses 128, 130 may be deeper than the recess constituting mounting portion 134. With this configuration, the height of the bottom surface of mounting portion 134 provided on second reinforcing portion 116-2 can be easily aligned with the bottom surfaces of mounting portions 134 provided on first reinforcing portion 116-1 and third reinforcing portion 116-3.

[0064] Some of the bus bars 132 are strip-shaped and extend in the arrangement direction B, and are mounted on the mounting portions 134 of the sixth reinforcement portion 116-6 and the eighth reinforcement portion 116-8. Other bus bars 132 are generally ladder-shaped and extend in the arrangement direction B, and are mounted across the mounting portions 134 of the first reinforcement portion 116-1, the second reinforcement portion 116-2, and the third reinforcement portion 116-3.

[0065] The ladder-shaped busbar 132 is composed of a first busbar portion 132a, a second busbar portion 132b, and a third busbar portion 132c. The first busbar portion 132a is a strip-shaped body extending in the arrangement direction B and is mounted on the mounting portion 134 of the first reinforcement portion 116-1. The second busbar portion 132b is a strip-shaped body extending in the arrangement direction B and is mounted on the mounting portion 134 of the third reinforcement portion 116-3. The third busbar portion 132c is a strip-shaped body extending in the orthogonal direction C and is mounted on the mounting portions 134 of the first connecting portion 124, the second reinforcement portion 116-2, and the second connecting portion 126. One end of the third busbar portion 132c is connected to the first busbar portion 132a, and the other end is connected to the second busbar portion 132b. In this embodiment, the multiple third busbar portions 132c are aligned in the arrangement direction B. The dimension of each busbar portion in the orthogonal direction C may be smaller than the inner dimension of the corresponding mounting portion 134 in the orthogonal direction C. With this configuration, a gap is generated between each busbar portion and the mounting portion 134. This gap can absorb the variation in the position of each reinforcing portion and each busbar portion when the distance in the orthogonal direction C varies between each reinforcing portion.

[0066] An electrode lead of the first power storage device 1-1 and an electrode lead of the second power storage device 1-2 are connected to the first busbar portion 132a. An electrode lead of the third power storage device 1-3 and an electrode lead of the fourth power storage device 1-4 are connected to the second busbar portion 132b. For example, each electrode lead is joined to each busbar portion by a known joining process such as laser welding. By interposing a reinforcing member 114 between each power storage device 1 and the busbar 132, electrical connection between each power storage device 1 and the busbar 132 in areas other than the electrode leads can be suppressed.

[0067] In this embodiment, each mounting portion 134 has a portion of the side wall extending in the arrangement direction B cut out. Each electrode lead passes through this cut out portion and is connected to the first busbar portion 132a or the second busbar portion 132b. This allows each electrode lead to be easily connected to each busbar portion. Furthermore, because the position of each electrode lead is restricted by the cut out, it is possible to prevent the electrode leads from overlapping each other.

[0068] For example, two adjacent housing sections 12 in the energy storage device 1 are defined as a pair of housing sections 12 (housing section units). Preferably, two housing sections are defined as a housing section unit, with the sealing section 14 located between the two housing sections 12 being bent upward with respect to the busbar section to which the electrode leads extending from the housing sections 12 are connected (i.e., protruding in a direction away from the busbar section). The notches in the side walls of the mounting section 134 are obliquely provided so that the two electrode leads in each housing section unit extend in a direction toward each other. This allows the electrode leads extending from each housing section unit to be spaced apart from each other between two adjacent housing sections. In this configuration, the first connecting section 124 and the second connecting section 126 are connected to the first reinforcing section 116-1 and the third reinforcing section 116-3 in the region between the two adjacent housing sections. This makes it easy to prevent the first connecting section 124 and the second connecting section 126 from interfering with the electrode leads.

[0069] In the present embodiment, the first power storage device 1-1 and the second power storage device 1-2 are oriented such that their first electrode leads 8 face the first busbar portion 132a. The third power storage device 1-3 and the fourth power storage device 1-4 are oriented such that their second electrode leads 10 face the third busbar portion 132c. The first electrode leads 8 of the first power storage device 1-1 and the second power storage device 1-2 are connected to the first busbar portion 132a. The second electrode leads 10 of the third power storage device 1-3 and the fourth power storage device 1-4 are connected to the second busbar portion 132b. The third busbar portion 132c electrically connects the first power storage device 1-1 and the second power storage device 1-2 to the third power storage device 1-3 and the fourth power storage device 1-4.

[0070] Further, the second electrode leads 10 of the first power storage device 1-1 and the second power storage device 1-2 are connected to a bus bar 132 mounted on the sixth reinforcing portion 116-6. The first electrode leads 8 of the third power storage device 1-3 and the fourth power storage device 1-4 are connected to a bus bar 132 mounted on the eighth reinforcing portion 116-8. As a result, the first power storage device 1-1 and the second power storage device 1-2 are connected in parallel with each other. Furthermore, the third power storage device 1-3 and the fourth power storage device 1-4 are connected in parallel with each other. Furthermore, the first power storage device 1-1 and the second power storage device 1-2 and the third power storage device 1-3 and the fourth power storage device 1-4 are connected in series with each other.

[0071] The manner of electrical connection of each power storage device 1 is not limited to the above. For example, the first power storage device 1-1 to the fourth power storage device 1-4 may all be connected in series, or may all be connected in parallel. Furthermore, in the present embodiment, in each power storage device 1, the multiple first electrode leads 8 protrude to the same side and are connected to the same bus bar 132, but the manner of electrical connection of each electrode body 2 is not particularly limited. For example, in each power storage device 1, the first electrode leads 8 and the second electrode leads 10 may be arranged alternately, and adjacent first electrode leads 8 and second electrode leads 10 may be electrically connected. In other words, in each power storage device 1, the multiple electrode bodies 2 may be connected in series.

[0072] Furthermore, the first electrode lead 8 and the second electrode lead 10 may protrude to the same side in the axial direction A. This allows the electrode bodies 2 to be electrically connected simply by arranging the bus bar 132 on only one side of the energy storage module 100. This allows the number of steps required to assemble the energy storage module 100 to be reduced.

[0073] FIG. 9(A) is a perspective view of the power storage module group 200. FIG. 9(B) is a side view of a portion of the power storage module group 200. A plurality of power storage modules 100 of the present embodiment are arranged, for example, in the orthogonal direction C to form the power storage module group 200. In the power storage module group 200, two adjacent power storage modules 100 are connected in series by, for example, the ladder-shaped bus bar 132 described above. That is, two adjacent power storage modules 100 are arranged such that the first power storage device 1-1 of one power storage module 100 and the fourth power storage device 1-4 of the other power storage module 100 are adjacent to each other. The first power storage device 1-1 and the second power storage device 1-2 of one power storage module 100 and the third power storage device 1-3 and the fourth power storage device 1-4 of the other power storage module 100 are connected in series by the ladder-shaped bus bar 132.

[0074] In two adjacent energy storage modules 100, the end holder 110 of one energy storage module 100 is replaced with the fourth holder 102-4 of the other energy storage module 100. The fifth reinforcing portion 116-5 of one energy storage module 100 and the fourth reinforcing portion 116-4 of the other energy storage module 100 are common to one another. The tenth reinforcing portion 116-10 of one energy storage module 100 and the ninth reinforcing portion 116-9 of the other energy storage module 100 are common to one another. In addition, when two energy storage modules 100 are connected in series by a ladder-shaped bus bar 132 as described above, the sixth reinforcing portion 116-6 of one energy storage module 100 is replaced with the first reinforcing portion 116-1. Furthermore, the tenth reinforcing portion 116-10 of one power storage module 100 (the ninth reinforcing portion 116-9 of the other power storage module) is replaced with the second reinforcing portion 116-2. Furthermore, the ninth reinforcing portion 116-9 of the other power storage module 100 is replaced with the third reinforcing portion 116-3.

[0075] As an example, the energy storage module group 200 has fixing devices 202 provided on both sides in the arrangement direction B. The position of the energy storage module group 200 is restricted by a pair of positioning members 204 extending in the perpendicular direction C on both sides of the arrangement direction B. In this state, the energy storage module group 200 is placed on a fixing base 206 provided on a mounting target such as a vehicle body. With the energy storage module group 200 placed on the fixing base 206, the fixing devices 202 and the fixing base 206 overlap. The fixing devices 202 and the fixing base 206 are then connected to each other with fastening members such as screws.

[0076] Each energy storage module 100 also includes a cover plate 136. The cover plate 136 is aligned with the multiple energy storage devices 1 in the axial direction A and covers the multiple energy storage devices 1. In this embodiment, a cover plate 136 is arranged on both sides of each energy storage module 100 in the axial direction A. The reinforcing member 114 also has a plate support groove 138 into which the cover plate 136 fits (see also FIG. 7 ). In other words, the reinforcing member 114 also serves as a support mechanism for the cover plate 136.

[0077] For example, the fourth reinforcing portion 116-4, the fifth reinforcing portion 116-5, and the seventh reinforcing portion 116-7 have plate support grooves 138. The cover plate 136 arranged on the same side in the axial direction A as the first to fifth reinforcing portions 116-1 to 116-5 is supported by the fourth reinforcing portion 116-4 and the fifth reinforcing portion 116-5 of one energy storage module 100. The cover plate 136 arranged on the same side in the axial direction A as the sixth to tenth reinforcing portions 116-6 to 116-10 is supported by the seventh reinforcing portion 116-7 of two adjacent energy storage modules 100. Note that some of the reinforcing portions facing the fixing base 206 (the seventh reinforcing portion 116-7 in this embodiment) also function as legs that abut against the fixing base 206 and support each energy storage module 100.

[0078] Specifically, the fourth reinforcing portion 116-4 and the fifth reinforcing portion 116-5 protrude further outward from the energy storage module 100 in the axial direction A than the first reinforcing portion 116-1 to the third reinforcing portion 116-3. Plate support grooves 138 extending in the arrangement direction B are provided on side surfaces of the fourth reinforcing portion 116-4 and the fifth reinforcing portion 116-5 facing the orthogonal direction C. The plate support groove 138 provided in the fourth reinforcing portion 116-4 and the plate support groove 138 provided in the fifth reinforcing portion 116-5 face each other in the orthogonal direction C. The cover plate 136 is inserted between the fourth reinforcing portion 116-4 and the fifth reinforcing portion 116-5, and both ends are supported by the plate support grooves 138 facing each other.

[0079] The seventh reinforcing portion 116-7 protrudes further in the axial direction A than the sixth reinforcing portion 116-6 and the eighth to tenth reinforcing portions 116-8 to 116-10. A plate support groove 138 extending in the arrangement direction B is provided on a side surface of the seventh reinforcing portion 116-7 facing the orthogonal direction C. The plate support grooves 138 provided on the seventh reinforcing portions 116-7 of two adjacent energy storage modules 100 face each other in the orthogonal direction C. The cover plate 136 is inserted between the two seventh reinforcing portions 116-7, and both ends are supported by the plate support grooves 138 facing each other. Note that when the energy storage module 100 is used alone, for example, the plate support grooves 138 may be provided in the ninth reinforcing portion 116-9 and the tenth reinforcing portion 116-10, and the cover plate 136 may be supported by the ninth reinforcing portion 116-9 and the tenth reinforcing portion 116-10.

[0080] As described above, the energy storage module 100 according to this embodiment includes a plurality of energy storage devices 1, a plurality of holders 102 that hold the plurality of energy storage devices 1, and reinforcing members 114 for the plurality of holders 102. The plurality of energy storage devices 1 include a first energy storage device 1-1 and a second energy storage device 1-2. Each of the first energy storage device 1-1 and the second energy storage device 1-2 includes a plurality of cylindrical electrode bodies 2, a plurality of housing sections 12 that individually encase the plurality of electrode bodies 2, and a film exterior body 4 that has sealing sections 14 that seal each housing section 12 and connect the plurality of housing sections 12 to one another, and is aligned in an arrangement direction B of the electrode bodies 2 and an orthogonal direction C that is orthogonal to an axial direction A of the electrode bodies 2.

[0081] The multiple holders 102 include a first holder 102-1 and a second holder 102-2. The first holder 102-1 has a first side plate 106-1 extending in the arrangement direction B. The first side plate 106-1 has multiple recesses 106a into which the respective accommodating sections 12 of the first power storage device 1-2 fit. The second holder 102-2 has a second side plate 106-2 extending in the arrangement direction B. The second side plate 106-2 has multiple recesses 106a into which the respective accommodating sections 12 of the second power storage device 1-2 fit.

[0082] The reinforcing member 114 has a first reinforcing portion 116-1, a second reinforcing portion 116-2, and a first connecting portion 124. The first reinforcing portion 116-1 extends in the arrangement direction B and is aligned with the first side plate 106-1 in the axial direction A, and has a side plate groove 120 into which the first side plate 106-1 fits on its surface facing the first side plate 106-1. The second reinforcing portion 116-2 extends in the arrangement direction B and is aligned with the second side plate 106-2 in the axial direction A, and has a side plate groove 120 into which the second side plate 106-2 fits on its surface facing the second side plate 106-2. The first connecting portion 124 connects the first reinforcing portion 116-1 and the second reinforcing portion 116-2, and is at least temporarily slidable relative to at least one of the first reinforcing portion 116-1 and the second reinforcing portion 116-2.

[0083] The energy storage device 1 is long in the arrangement direction B, and the film exterior body 4 is highly flexible. For this reason, when the energy storage device 1 receives an external impact or the like, the center portion in the arrangement direction B is likely to bend so as to protrude in the orthogonal direction C relative to both end portions. Furthermore, since the energy storage device 1 is long in the arrangement direction B, the side plates 106 are also long in the arrangement direction B. Furthermore, from the perspective of reducing the weight of the energy storage module 100, it is required that the thickness of the side plates 106 be made as thin as possible. Therefore, like the energy storage device 1, the side plates 106 are also likely to bend so that the center portion in the arrangement direction B protrudes in the orthogonal direction C. In particular, the side plates 106 have a plurality of recesses 106a aligned in the arrangement direction B, which makes them more likely to bend.

[0084] In contrast, by fitting the first reinforcing portion 116-1 into the end of the first side plate 106-1, the rigidity of the first holder 102-1 against the above-mentioned bending can be increased. Furthermore, by fitting the second reinforcing portion 116-2 into the end of the second side plate 106-2, the rigidity of the second holder 102-2 against the above-mentioned bending can be increased. Therefore, the holding strength of the first power storage device 1-1 and the second power storage device 1-2 can be increased. Furthermore, stress generated in the first holder 102-1 and the second holder 102-2 can be effectively reduced, thereby increasing the rigidity of the power storage module 100. Furthermore, compared to achieving the same rigidity by increasing the thickness of the side plate 106, an increase in the weight of the power storage module 100 can be suppressed. Therefore, it is easy to achieve both improved rigidity and a lighter weight for the power storage module 100.

[0085] Furthermore, the first reinforcing portion 116-1 and the second reinforcing portion 116-2 are connected to each other by the first connecting portion 124. This makes it possible to restrict relative displacement between the first reinforcing portion 116-1 and the second reinforcing portion 116-2. As a result, the holding strength of the first power storage device 1-1 and the second power storage device 1-2 can be further increased. Furthermore, the rigidity of the power storage module 100 can be further increased.

[0086] However, there is variation in the dimensions and shapes of the electrode bodies 2. Therefore, when connecting multiple device units 104, if the device units 104 are packed together so that the spacing between adjacent side plates 106 is uniform, there is a risk that some of the electrode bodies 2 will be excessively compressed. If excessive load is placed on the electrode bodies 2, this may lead to a decrease in the power generation performance of the energy storage device 1. For this reason, it is desirable to pack the device units 104 together so that, for example, the maximum value of pressure applied to the electrode bodies 2 between each energy storage device 1 is constant, so as to prevent excessive load from being placed on each electrode body 2. However, in this case, the spacing between adjacent side plates 106 will no longer be uniform.

[0087] In contrast, the first connection portion 124 of the present embodiment is at least temporarily slidable relative to at least one of the first reinforcing portion 116-1 and the second reinforcing portion 116-2. This allows the spacing between the first reinforcing portion 116-1 and the second reinforcing portion 116-2 to be flexibly changed depending on the spacing between the first side plate 106-1 and the second side plate 106-2. In other words, the sliding of the first connection portion 124 can absorb variations (tolerances) in the spacing between adjacent side plates 106. This makes it possible to increase the holding strength of each power storage device 1 while preventing excessive load from being applied to the electrode assembly 2.

[0088] Furthermore, the side plate 106 has a plurality of recesses 112a, and each of the accommodation sections 12 of the energy storage device 1 fits into each of the recesses 112a. This allows the energy storage device 1 to be held more stably. Therefore, the electrical connection between each of the energy storage devices 1 and the bus bar 132 can be more stably maintained, and damage to each of the energy storage devices 1 can be further suppressed. This improves the power generation performance and safety performance of the energy storage module 100. Furthermore, because the energy storage device 1 has a pouch structure in which the plurality of electrode bodies 2 are sealed in the film exterior body 4, the weight of the energy storage module 100 can be reduced compared to when each electrode body 2 is individually sealed in an exterior can.

[0089] Furthermore, the reinforcing member 114 of this embodiment has a plurality of first connection portions 124 aligned in the arrangement direction B. This makes it possible to further restrict relative displacement between the first reinforcing portion 116-1 and the second reinforcing portion 116-2. This further increases the holding strength of the first power storage device 1-1 and the second power storage device 1-2. Furthermore, the rigidity of the power storage module 100 can be further increased.

[0090] Furthermore, the first connecting portion 124 of the present embodiment is formed from a part of the member that constitutes the second reinforcing portion 116-2. The first connecting portion 124 extends from the second reinforcing portion 116-2 toward the first reinforcing portion 116-1 and is connected to the first reinforcing portion 116-1 so as to be slidable at least temporarily. In this manner, by integrally molding the first connecting portion 124 with the second reinforcing portion 116-2, the rigidity of the assembly of the first reinforcing portion 116-1, the second reinforcing portion 116-2, and the first connecting portion 124 can be increased. This can further increase the holding strength of the first power storage device 1-1 and the second power storage device 1-2, and further increase the rigidity of the power storage module 100. Furthermore, an increase in the number of parts due to the provision of the first connecting portion 124 can be suppressed.

[0091] The energy storage device 1 of this embodiment also includes a third energy storage device 1-3. The first energy storage device 1-1, the second energy storage device 1-2, and the third energy storage device 1-3 are arranged in this order in the orthogonal direction C. The holder 102 also includes a third holder 102-3. The third holder 102-3 has a third side plate 106-3 extending in the arrangement direction B. The third side plate 106-3 has a plurality of recesses 106a into which the housing portions 12 of the third energy storage devices 1-3 fit. The reinforcing member 114 has a third reinforcing portion 116-3 and a second connecting portion 126. The third reinforcing portion 116-3 extends in the arrangement direction B and is aligned with the third side plate 106-3 in the axial direction A. The third reinforcing portion 116-3 has a side plate groove 120 into which the third side plate 106-3 fits on the surface facing the third side plate 106-3. The second connecting portion 126 connects the second reinforcing portion 116-2 and the third reinforcing portion 116-3, and is at least temporarily slidable relative to at least one of the second reinforcing portion 116-2 and the third reinforcing portion 116-3.

[0092] By fitting the third reinforcing portion 116-3 into the end portion of the third side plate 106-3, the rigidity of the third holder 102-3 against the above-mentioned bending can be increased. Therefore, the holding strength of the third power storage device 1-3 can be increased. Furthermore, the rigidity of the power storage module 100 can be further increased. Furthermore, by connecting the second reinforcing portion 116-2 and the third reinforcing portion 116-3 with the second connecting portion 126, the holding strength of the second power storage device 1-2 and the third power storage device 1-3 can be further increased. Furthermore, the rigidity of the power storage module 100 can be further increased. Furthermore, by making the second connecting portion 126 at least temporarily slidable relative to at least one of the second reinforcing portion 116-2 and the third reinforcing portion 116-3, the holding strength of each power storage device 1 can be increased while preventing excessive load from being applied to the electrode assembly 2.

[0093] Furthermore, the reinforcing member 114 of this embodiment has a plurality of second connection portions 126 aligned in the arrangement direction B. This makes it possible to further restrict relative displacement between the second reinforcing portion 116-2 and the third reinforcing portion 116-3. This further increases the holding strength of the second power storage device 1-2 and the third power storage device 1-3. Furthermore, the rigidity of the power storage module 100 can be further increased.

[0094] Furthermore, the second connection portion 126 in this embodiment is formed from a part of the member that constitutes the second reinforcing portion 116-2. The second connection portion 126 extends from the second reinforcing portion 116-2 toward the third reinforcing portion 116-3 and is connected to the third reinforcing portion 116-3 so as to be slidable at least temporarily. In this manner, by integrally molding the second connection portion 126 with the second reinforcing portion 116-2, the rigidity of the assembly of the second reinforcing portion 116-2, the third reinforcing portion 116-3, and the second connection portion 126 can be increased. This can further increase the holding strength of the second power storage device 1-2 and the third power storage device 1-3, and further increase the rigidity of the power storage module 100. Furthermore, an increase in the number of parts due to the provision of the second connection portion 126 can be suppressed.

[0095] The energy storage module 100 of the present embodiment also includes bus bars 132 that electrically connect the plurality of electrode bodies 2. The reinforcing members 114 are insulating and have mounting portions 134 for the bus bars 132. This allows the reinforcing members 114 to reinforce the holder 102 and insulate the bus bars 132. Therefore, an increase in the number of parts in the energy storage module 100 due to the provision of the reinforcing members 114 can be suppressed.

[0096] Furthermore, some of the busbars 132 in this embodiment have a first busbar portion 132a, a second busbar portion 132b, and a third busbar portion 132c. The first busbar portion 132a extends in the arrangement direction B and is connected to an electrode lead of the first power storage device 1-1 and an electrode lead of the second power storage device 1-2. The second busbar portion 132b extends in the arrangement direction B and is connected to an electrode lead of the third power storage device 1-3. The third busbar portion 132c is connected to the first busbar portion 132a and the second busbar portion 132b. The first reinforcement portion 116-1 has a mounting portion 134 for the first busbar portion 132a, the third reinforcement portion 116-3 has a mounting portion 134 for the second busbar portion 132b, and the first connecting portion 124, the second reinforcement portion 116-2 and the second connecting portion 126 have a mounting portion 134 for the third busbar portion 132c.

[0097] In this way, by using the assembly of the first reinforcing portion 116-1 to the third reinforcing portion 116-3, the first connecting portion 124, and the second connecting portion 126 as an insulating plate supporting the approximately ladder-shaped bus bar 132 having the first bus bar portion 132a to the third bus bar portion 132c, it is possible to efficiently insulate the bus bar 132.

[0098] Moreover, first reinforcing portion 116-1 of the present embodiment has recess 128 that accommodates a portion of first connecting portion 124, and mounting portion 134 of first reinforcing portion 116-1 is configured as a recess. In axial direction A, the bottom surface of recess 128 is farther away from bus bar 132 than the bottom surface of mounting portion 134. In addition, third reinforcing portion 116-3 of the present embodiment has recess 130 that accommodates a portion of second connecting portion 126, and mounting portion 134 of third reinforcing portion 116-3 is configured as a recess. In axial direction A, the bottom surface of recess 130 is farther away from bus bar 132 than the bottom surface of mounting portion 134. With these configurations, the heights of the bottom surfaces of mounting portions 134 provided on first reinforcing portion 116-1 to third reinforcing portion 116-3 can be easily aligned.

[0099] The energy storage module 100 of this embodiment also includes a cover plate 136 that is aligned with the plurality of energy storage devices 1 in the axial direction A and covers the plurality of energy storage devices 1. The reinforcing member 114 has a plate support groove 138 into which the cover plate 136 fits. This allows the reinforcing member 114 to reinforce the holder 102 and support the cover plate 136. Therefore, an increase in the number of parts of the energy storage module 100 due to the provision of the reinforcing member 114 can be suppressed.

[0100] Furthermore, the side plates 106 of the present embodiment are corrugated with repeated recesses and protrusions in the arrangement direction B, and are sandwiched between two energy storage devices 1, with each of the accommodation sections 12 of one energy storage device 1 fitting into each of the recesses 106a when viewed from one main surface, and each of the accommodation sections 12 of the other energy storage device 1 fitting from the back surface into each of the protrusions 106b when viewed from the main surface. This can further improve the stability of each energy storage device 1 in the energy storage module 100. Note that if at least one of the side plates 106 included in the energy storage module 100 is corrugated, the stability of the energy storage device 1 can be improved at least slightly. Furthermore, by making the side plates 106 corrugated, the weight of the holder 102 can be reduced.

[0101] Furthermore, the film exterior body 4 of the present embodiment bends or curves between adjacent housing sections 12 and meanders in the arrangement direction B. This allows the length of the energy storage device 1 to be shorter than when the film exterior body 4 is not folded, without making the sealing section 14 smaller. As a result, it is possible to increase the number of electrode assemblies 2 mounted in the energy storage module 100, or to reduce the size of the energy storage module 100 without reducing the number of electrode assemblies 2 mounted. In other words, according to the present embodiment, it is possible to improve the energy density of the energy storage module 100 while suppressing a deterioration in the sealing performance of the electrode assemblies 2.

[0102] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the invention defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Furthermore, any combination of components included in each embodiment is also valid as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched object. [Explanation of symbols]

[0103] REFERENCE SIGNS LIST 1 Energy storage device, 1-1 First energy storage device, 1-2 Second energy storage device, 1-3 Third energy storage device, 2 Electrode body, 4 Film exterior body, 12 Housing section, 14 Sealing section, 100 Energy storage module, 102 Holder, 102-1 First holder, 102-2 Second holder, 102-3 Third holder, 106 Side plate, 106a Recessed section, 106b Convex section, 106-1 First side plate, 106-2 Second side plate, 106-3 Third side plate, 114 Reinforcing member, 116-1 First reinforcing section, 116-2 Second reinforcing section, 116-3 Third reinforcing section, 120 Side plate groove, 124 First connecting section, 126 Second connecting section, 132 Busbar, 132a first busbar portion, 132b second busbar portion, 132c third busbar portion, 134 mounting portion, 136 cover plate, 138 plate support groove.

Claims

1. A plurality of power storage devices; a plurality of holders for holding the plurality of power storage devices; a reinforcing member for the plurality of holders; the plurality of power storage devices include a first power storage device and a second power storage device, the first storage battery device and the second storage battery device each have a plurality of cylindrical electrode bodies, a plurality of housing sections that individually encase the plurality of electrode bodies, and a film exterior body having sealing sections that seal each housing section and connect the plurality of housing sections to one another, the electrode bodies being arranged in an orthogonal direction that is orthogonal to the arrangement direction of the electrode bodies and the axial direction of the electrode bodies; the plurality of holders include a first holder and a second holder; the first holder includes a first side plate extending in the arrangement direction, the first side plate having a plurality of recesses into which the housing portions of the first power storage device fit; the second holder includes a second side plate extending in the arrangement direction and having a plurality of recesses into which the housing portions of the second power storage device fit, the reinforcing member has a first reinforcing portion, a second reinforcing portion, and a first connecting portion, the first reinforcing portion extends in the arrangement direction and is aligned with the first side plate in the axial direction, and has a side plate groove portion in which the first side plate fits on a surface facing the first side plate; the second reinforcing portion extends in the arrangement direction and is aligned with the second side plate in the axial direction, and has a side plate groove portion in which the second side plate fits on a surface facing the second side plate, the first connection portion connects the first reinforcing portion and the second reinforcing portion and is at least temporarily slidable relative to at least one of the first reinforcing portion and the second reinforcing portion; Energy storage module.

2. the first connection portion is configured as a part of a member constituting the second reinforcement portion, extends from the second reinforcement portion toward the first reinforcement portion, and is connected to the first reinforcement portion in a slidable manner at least temporarily; The energy storage module according to claim 1 .

3. the first reinforcing portion has a recess in which a portion of the first connecting portion is accommodated, a gap is provided between the recess and the portion of the first connection portion in at least one direction of the orthogonal direction and the arrangement direction; The energy storage module according to claim 2 .

4. the plurality of power storage devices includes a third power storage device, the first power storage device, the second power storage device, and the third power storage device are arranged in this order in the orthogonal direction, the plurality of holders includes a third holder, the third holder includes a third side plate extending in the arrangement direction, the third side plate having a plurality of recesses into which the housing portions of the third power storage device fit, the reinforcing member has a third reinforcing portion and a second connecting portion, the third reinforcing portion extends in the arrangement direction and is aligned with the third side plate in the axial direction, and has a side plate groove portion in which the third side plate fits on a surface facing the third side plate, the second connection portion connects the second reinforcing portion and the third reinforcing portion, and is at least temporarily slidable relative to at least one of the second reinforcing portion and the third reinforcing portion; The energy storage module according to claim 1 .

5. the second connection portion is configured as a part of a member constituting the second reinforcing portion, extends from the second reinforcing portion toward the third reinforcing portion, and is connected to the third reinforcing portion in a slidable manner at least temporarily; The electricity storage module according to claim 4 .

6. the third reinforcing portion has a recess in which a portion of the second connecting portion is accommodated, a gap is provided between the recess and the portion of the second connection portion in at least one direction of the orthogonal direction and the arrangement direction; The electricity storage module according to claim 5 .

7. the energy storage module includes a bus bar that electrically connects the plurality of electrode assemblies, the reinforcing member has insulating properties and has a mounting portion for the bus bar on a surface facing away from the holder. The energy storage module according to claim 1 .

8. the energy storage module includes a bus bar that electrically connects the plurality of electrode assemblies, the first power storage device, the second power storage device, and the third power storage device each have an electrode lead electrically connected to the electrode body; The bus bar is a first busbar portion extending in the arrangement direction and to which the electrode lead of the first power storage device and the electrode lead of the second power storage device are connected; a second busbar portion extending in the arrangement direction and connected to the electrode lead of the third power storage device; a third bus bar portion connected to the first bus bar portion and the second bus bar portion, the first reinforcing portion has insulating properties and includes a mounting portion for the first busbar portion, the third reinforcing portion has insulating properties and includes a mounting portion for the second bus bar portion, the first connecting portion, the second reinforcing portion, and the second connecting portion are insulating and have a mounting portion for the third busbar portion. The energy storage module according to claim 4 .

9. the first reinforcing portion has a recess in which a portion of the first connecting portion is accommodated, the mounting portion of the first reinforcing portion is configured as a recess, a bottom surface of the recess in which a portion of the first connection portion is accommodated is spaced from the bus bar in the axial direction relative to a bottom surface of the mounting portion of the first reinforcing portion. The power storage module according to claim 8 .

10. the third reinforcing portion has a recess that accommodates a portion of the second connecting portion, the mounting portion of the third reinforcing portion is configured as a recess, a bottom surface of the recess in which a portion of the second connection portion is accommodated is spaced apart from the bus bar in the axial direction from a bottom surface of the mounting portion of the third reinforcing portion; The electricity storage module according to claim 8 or 9.

11. the power storage module includes a cover plate aligned with the plurality of power storage devices in the axial direction and covering the plurality of power storage devices; The reinforcing member has a plate support groove into which the cover plate fits. The energy storage module according to claim 1 .

12. At least one of the first side plate and the second side plate has repeated concave and convex portions in the arrangement direction. a corrugated plate-like structure sandwiched between the two power storage devices; Each of the storage portions of one of the power storage devices is fitted into each of the recesses when viewed from one main surface side, and each of the storage portions of the other of the power storage devices is fitted from the back surface side into each of the protrusions when viewed from the main surface side. The energy storage module according to any one of claims 1 to 11.

13. The film exterior body bends or curves between adjacent storage sections and meanders in the arrangement direction. The energy storage module according to any one of claims 1 to 12.

Images