Energy storage module

Abstract

This electric power storage module comprises an electric power storage device, a holder for holding the electric power storage device, and a reinforcement member for the holder. The electric power storage device has: a plurality of cylindrical electrode bodies; and a film outer casing that has a plurality of housing parts which envelop the plurality of electrode bodies individually and a sealing part which seals the housing parts and connects the plurality of housing parts to each other. The holder has a side plate that extends in the direction of alignment of the plurality of electrode bodies and that has a plurality of depressions into which the housing parts fit along the direction of alignment. The reinforcement member extends in the alignment direction, lines up with the holder in the axial center direction of the electrode bodies, and has on the surface facing the holder direction a first groove part into which the side plate fits.

Description

Technical Field

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

Background Art

[0002] Conventionally, a power storage module in which a plurality of cylindrical power storage devices (for example, batteries) are mounted is 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 a wound electrode body is accommodated in each outer can.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The power storage module may be used as a power source for in-vehicle use or for a portable terminal. Therefore, weight reduction of the power storage module is desired. As a method for reducing the weight of the power storage module, it is conceivable to wrap a plurality of electrode bodies with a common film exterior while maintaining the individual sealing properties. Thereby, since the outer cans for accommodating the respective electrode bodies can be eliminated, the weight of the power storage module can be reduced. On the other hand, a power storage device having a structure in which a plurality of electrode bodies are sealed with a film exterior is likely to be greatly deformed by an impact or the like due to the high flexibility of the film exterior. Therefore, it is desired to increase the holding strength of the power storage device.

[0005] The present disclosure has been made in view of such circumstances, and one of its objects is to provide a technique for increasing the holding strength of a power storage device having a structure in which a plurality of electrode bodies are sealed with a film exterior.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a power storage module. This power storage module includes a power storage device, a holder for holding the power storage device, and a reinforcing member for the holder. The power storage device has a plurality of cylindrical electrode bodies, a plurality of accommodating portions that individually wrap the plurality of electrode bodies, and a film exterior body that seals each accommodating portion and connects the plurality of accommodating portions to each other. The holder has a side plate that extends in the arrangement direction of the plurality of electrode bodies and has a plurality of recesses in which the accommodating portions are fitted side by side in the arrangement direction. The reinforcing member extends in the arrangement direction and is arranged side by side with the holder in the axial direction of the electrode body, and has a first groove portion on the surface facing the holder side into which the side plate is fitted.

[0007] Any combination of the above components, as well as those obtained by converting the expressions of the present disclosure among methods, devices, systems, etc., are also valid as aspects of the present disclosure.

Advantages of the Invention

[0008] According to the present disclosure, the holding strength of a power storage device having a structure in which a plurality of electrode bodies are sealed with a film exterior body can be increased.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present disclosure will be described with reference to the drawings based on preferred embodiments. The embodiments are illustrative rather than limiting 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, members, and processes shown in each drawing are denoted by the same reference numerals, and repeated explanations are appropriately omitted. Also, the scales and shapes of the respective parts shown in each figure are set for convenience in order to facilitate the explanation, and are not to be construed in a limited manner unless otherwise specified. Further, when terms such as "first", "second", etc. are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are for distinguishing one configuration from another. Also, in each drawing, some of the members that are not important in explaining the embodiments are shown with omission.

[0011] FIG. 1 is a perspective view of the power storage device 1 included in the power storage module 100 according to the embodiment. FIG. 2(A) is a schematic view of the power storage device 1 viewed from the axial direction A. FIG. 2(B) is a schematic view of the power storage device 1 viewed from the second direction C. In FIG. 2(B), for convenience of explanation, the inside of the film exterior body 4 is also shown. Also, the state before folding the film exterior body 4 is shown by a broken line. In the present embodiment, the direction in which the axis of the spiral of the electrode body 2 extends is defined as the axial direction A, the arrangement direction of the plurality of electrode bodies 2 is defined as the first direction B, and the direction orthogonal to the axial direction A and the first direction B is defined as the second direction C.

[0012] The power storage device 1 of the present embodiment is, for example, a rechargeable secondary battery such as a lithium ion battery, a nickel-hydrogen battery, 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 the present embodiment includes 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 a strip-shaped first electrode plate and a strip-shaped second electrode plate are laminated with an electrode separator sandwiched therebetween, having a wound structure wound in a spiral shape. 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, and one end of each is welded to each electrode plate. The plurality of electrode bodies 2 are arranged in the first direction B at a predetermined interval with their postures determined such that the axial direction A of each electrode body 2 is parallel to each other. The plurality of electrode bodies 2 are wrapped by a common film exterior body 4.

[0014] The film exterior body 4 has a structure in which, for example, two laminated films are laminated. Each laminated film has a structure in which a thermoplastic resin sheet is laminated on both sides of a metal sheet such as aluminum. Further, the film exterior body 4 has a plurality of accommodating portions 12 and a sealing portion 14. The plurality of accommodating portions 12 are arranged in the first direction B at a predetermined interval. Each accommodating portion 12 is cylindrical and individually wraps and accommodates each electrode body 2. Each accommodating portion 12 is constituted by a bag portion provided in the film exterior body 4. The bag portion is a portion separated from each other in the two laminated films. Therefore, each accommodating portion 12 protrudes from the sealing portion 14 along the shape of the side surface of the electrode body 2. An electrolytic solution 16 is accommodated in each accommodating portion 12 together with the electrode body 2.

[0015] The sealing portion 14 surrounds the outer periphery of each accommodating portion 12 and seals each accommodating portion 12. The sealing portion 14 is constituted by, for example, 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 bonding treatment, and the thermoplastic resin sheets of the two laminated films are welded to each other. The sealing portion 14 seals each accommodating portion 12 and connects the plurality of accommodating portions 12 to each other.

[0016] The end portions of the first electrode lead 8 and the second electrode lead 10 on the side opposite to the side 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 the present embodiment, the first electrode lead 8 and the second electrode lead 10 connected to each electrode body 2 protrude in opposite directions to each other in the axial direction A. Also, each first electrode lead 8 protrudes on the same side. Note that the first electrode lead 8 and the second electrode lead 10 may protrude on the same side in the axial direction A.

[0017] The film exterior body 4 is refracted or curved between adjacent accommodating portions 12 and extends in a zigzag manner. By folding the film exterior body 4 in a zigzag manner, the interval between the accommodating portions 12 in the first direction B can be made narrower than in the state before folding, and thus the length of the power storage device 1 in the first direction B can be shortened. Also, in the present embodiment, the plurality of accommodating portions 12 are arranged such that their respective centers are aligned on the same straight line when viewed from the axial direction A with the film exterior body 4 extending in a zigzag manner. Thereby, it is possible to suppress an increase in the dimension of the power storage device 1 in the second direction C as compared with the case where the plurality of accommodating portions 12 are arranged such that their centers are displaced in the second direction C. Also, the sealed portion 14 bent in a zigzag shape is accommodated inside the accommodating portion 12 in the second direction C. Thereby, it is possible to suppress an increase in the dimension of the power storage device 1 in the second direction C due to the folding of the film exterior body 4. Note that in the present disclosure, the centers of the plurality of accommodating portions 12 do not necessarily have to be located on the same straight line.

[0018] The sealed portion 14 has a pair of first side portions 14a and a pair of second side portions 14b that surround the periphery of each accommodating portion 12. The pair of first side portions 14a are arranged in the axial direction A with each accommodating portion 12 therebetween, and seal the end portions of each accommodating portion 12 in the axial direction A. The first side portion 14a of the present embodiment extends linearly passing through the center of the accommodating portion 12 when viewed from the axial direction A. The pair of second side portions 14b are arranged in a direction orthogonal to the axial direction A with each accommodating portion 12 therebetween, extend in the axial direction A, and connect the pair of first side portions 14a.

[0019] The two second side portions 14b located between two adjacent accommodating portions 12 are connected to each other at a predetermined angle θ, that is, non-linearly. Further, the directions in which the connecting portions of the two second side portions 14b are refracted or curved are staggered in the plurality of connecting portions arranged in the first direction B. As a result, the film exterior body 4 extends in a zigzag manner in the first direction B.

[0020] An example of a method for manufacturing the power storage device 1 is shown below. FIGS. 3(A) to 3(C) and FIGS. 4(A) to 4(C) are process diagrams of the method for manufacturing the power 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 plurality of depressions 18 are formed, for example, by subjecting the first laminate film 20a to a known process such as pressing. The 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 on the first electrode lead 8 and the second electrode lead 10.

[0021] Subsequently, as shown in FIG. 3(B), a second laminate film 20b is superposed on the first laminate film 20a to form the film exterior body 4. In the second laminate film 20b, semi-cylindrical depressions 18 are provided at positions facing the respective depressions 18 of the first laminate film 20a. Therefore, when the first laminate film 20a and the second laminate film 20b are superposed, a pair of depressions 18 form a bag portion, in other words, an accommodating portion 12. 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 accommodated in the accommodating portion 12, the tips of the first electrode lead 8 and the second electrode lead 10 protrude outside the film exterior body 4.

[0022] Subsequently, as shown in FIG. 3(C), a thermocompression bonding process is performed on a part of the film exterior body 4 to form a welded part 22. The portion of the film exterior body 4 where the thermocompression bonding process is not performed becomes a non-welded part 24. The non-welded part 24 is arranged so as to connect each accommodating part 12 and the outside of the film exterior body 4. In the present embodiment, the non-welded part 24 is provided so as to connect the side where the first electrode lead 8 protrudes among the four sides of each accommodating part 12 and the outside of the film exterior body 4. The remaining three sides of each accommodating part 12 are surrounded by the welded part 22. The interface between the film exterior body 4 and the second electrode lead 10 is sealed with a sealant.

[0023] Subsequently, as shown in FIG. 4(A), the electrolytic solution 16 is injected into each accommodating part 12 through the non-welded part 24. After the injection of the electrolytic solution 16, as shown in FIG. 4(B), a thermocompression bonding process is also performed on the non-welded part 24. As a result, a sealing part 14 surrounding the entire circumference of each accommodating part 12 is formed. The interface between the film exterior body 4 and the first electrode lead 8 is sealed with a sealant. Subsequently, as shown in FIG. 4(C), the film exterior body 4 is folded in a zigzag shape. Through the above steps, the power storage device 1 is obtained.

[0024] Note that the manufacturing method of the power storage device 1 is not limited to the above-described one. For example, one laminate film having a length twice that of the power storage device 1 may be used, and each electrode body 2 may be wrapped by folding this laminate film in half. Also, when the required amount of the electrolytic solution 16 is small, the injection step of the electrolytic solution 16 shown in FIG. 4(A) can be omitted by previously infiltrating the electrolytic solution 16 into the electrode separator. In this case, in the thermocompression bonding step shown in FIG. 3(C), a thermocompression bonding process is performed on the entire circumference of each accommodating part 12 to form the sealing part 14.

[0025] The power storage device 1 is incorporated into a power storage module 100 according to the present embodiment described below. FIG. 5 is a perspective view of the power storage module 100 according to the embodiment. FIG. 6 is an exploded perspective view of the power storage module 100. FIG. 7(A) is a plan view of the reinforcing member 128, and FIG. 7(B) is a perspective view of the holder 104.

[0026] The power storage module 100 includes a power storage device 1, a holder 104, a reinforcing member 128, and a bus bar 108 (current collector plate). Further, the power storage module 100 of the present embodiment includes a plurality of power storage devices 1. As an example, one power storage device 1, one holder 104, and two reinforcing members 128 are combined to form one device unit 130, and the power storage module 100 includes two device units 130. Note that the number of device units 130 included in the power storage module 100 is not particularly limited, and may be one, or three or more. Also, in the device unit 130, a plurality of power storage devices 1 may be assembled to one holder 104. Further, one or three or more reinforcing members 128 may be assembled to one holder 104.

[0027] Each device unit 130 is arranged in the second direction C. Also, the posture of each device unit 130 is determined such that the accommodating portions 12 of the power storage devices 1 are aligned in the same direction. Two adjacent power storage devices 1 in the second direction C are displaced from each other in the first arrangement direction B such that the axis of the electrode body 2 of the other power storage device 1 is located between the axes of two adjacent electrode bodies 2 in one power storage device 1. That is, the accommodating portion 12 of the other power storage device 1 fits into the valley between the two accommodating portions 12 of one power storage device 1. Thereby, the dimension of the power storage module 100 in the second direction C can be reduced.

[0028] In each device unit 130, the power storage device 1 is held by the holder 104. The holder 104 has a side plate 112 and a pair of protruding portions 114. The side plate 112 is a rectangular plate extending in the first direction B. The pair of protruding portions 114 are rectangular plates protruding from both ends of the side plate 112 in the first direction B in a direction intersecting the first direction B and the axial direction A. The protruding portion 114 of the present embodiment protrudes in the second direction C. The pair of protruding portions 114 face each other in the first direction B. Therefore, the holder 104 has a substantially U-shaped configuration that is long in the first direction B. The posture of the holder 104 is determined such that the main surface of the side plate 112 faces the second direction C and the main surface of each protruding portion 114 faces the first direction B.

[0029] The holder 104 is composed of, for example, a single plate material. The side plates 112 and the pair of protrusions 114 can be formed by bending both ends of a metal plate. Note that if rigidity equal to or higher than a predetermined level can be obtained, the holder 104 may be made of resin. Further, the side plates 112 and the protrusions 114, which are separate from each other, may be joined to form the holder 104. Examples of the metal used for the holder 104 include aluminum, aluminum alloy, steel, and the like. Examples of the resin used for the holder 104 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 and glass fiber-reinforced plastics.

[0030] The power storage device 1 is surrounded by the holder 104 in three directions in the first direction B and the second direction C. The side plate 112 covers one surface of the power storage device 1 in the second direction C. The pair of protrusions 114 covers both surfaces of the power storage device 1 in the first direction B. As an example, the side plate 112 is fixed to the opposing power storage device 1 with an adhesive. The adhesive is preferably an insulating adhesive. Note that an insulating sheet may be interposed between the power storage device 1 and the holder 104.

[0031] Each power storage device 1 is arranged in the second direction C in a state where the holder 104 is assembled. At this time, each power storage device 1 is arranged such that the exposed surfaces not covered by the holder 104 face the same direction. In a state where each power storage device 1 is arranged, the exposed surface of each power storage device 1 is covered with the side plate 112 of the adjacent device unit 130 and fixed with an adhesive. Thereby, at least a part of the power storage devices 1 is sandwiched between two side plates 112. Further, at least a part of the side plates 112 is sandwiched between two power storage devices 1.

[0032] Further, each protruding portion 114 has a tip portion 114a and a base end portion 114b. The base end portion 114b is interposed between the side plate 112 and the tip portion 114a. The tip portion 114a is displaced in a direction away from the power storage device 1 with respect to the base end portion 114b. Therefore, the interval between the pair of protruding portions 114 is wider on the tip portion 114a side than on the base end portion 114b side. And each tip portion 114a protrudes to a position overlapping the base end portion 114b of the adjacent holder 104 when viewed from the first direction B.

[0033] That is, when a plurality of device units 130 are arranged in the second direction C, in two adjacent holders 104, the side plate 112 and the pair of base end portions 114b in the other holder 104 enter between the pair of tip portions 114a in one holder 104. And a known joining process such as laser welding is performed on the overlapping portion of the tip portion 114a of one holder 104 and the base end portion 114b of the other holder 104. As a result, each holder 104 is connected and the plurality of device units 130 are integrated.

[0034] The side plate 112 has a plurality of recesses 112a arranged in the first direction B. Each recess 112a is in a groove shape extending in the axial direction A. And in a state where the holder 104 is assembled to the power storage device 1, each housing portion 12 of the power storage device 1 facing the side plate 112 fits into each recess 112a. As a result, the side plate 112 extends along the curved surface of each housing portion 12. Thereby, the power storage device 1 can be held more stably. In particular, the displacement of the power storage device 1 in the first direction B can be restricted.

[0035] In addition, the side plate 112 of the present embodiment is in a corrugated plate shape with unevenness repeating in the first direction B. That is, when viewed from one main surface side, a plurality of concave portions 112a and a plurality of convex portions 112b are arranged alternately in the first direction B. For this reason, each housing portion 12 of the power storage devices 1 arranged with the side plate 112 interposed therebetween can be fitted into the side plate 112. Specifically, regarding the concave portions 112a and the convex portions 112b when the side plate 112 is viewed from one main surface side, each housing portion 12 of one power storage device 1 fits into each concave portion 112a. Further, each housing portion 12 of the other power storage device 1 fits into each convex portion 112b (which becomes a concave portion when viewed from the opposite side) from the back surface side. Thereby, the stability of each power storage device 1 in the power storage module 100 can be further enhanced. Note that the side plate 112 may be a plate material having a thickness greater than that of a corrugated plate and provided with a plurality of concave portions arranged in the first direction B on both surfaces.

[0036] The device unit 130 located at one end in the second direction C has no other device unit 130 on the exposed surface side. For this reason, an end holder (not shown) is assembled to the exposed surface of the power storage device 1 in the device unit 130. As an example, the end holder has a shape similar to that of the holder 104 except that the protruding direction of the protruding portion 114 is opposite to that of the holder 104 and the protruding portion 114 does not have a tip portion 114a.

[0037] In addition, a plurality of through holes 132 are provided in the side plate 112 and the pair of protruding portions 114 of the present embodiment. The plurality of through holes 132 provided in the side plate 112 penetrate the side plate 112 in the plate thickness direction of the side plate 112. Further, the plurality of through holes 132 are arranged in a matrix. Similarly, the plurality of through holes 132 provided in each protruding portion 114 penetrate the protruding portion 114 in the plate thickness direction of the protruding portion 114. Further, the plurality of through holes 132 are arranged in a matrix. By providing the through holes 132, the weight reduction of the power storage module 100 can be achieved.

[0038] The reinforcing member 128 is a member that fits into the holder 104 to enhance the rigidity of the holder 104. The reinforcing member 128 is aligned with the holder 104 in the axial direction A. In the present embodiment, the reinforcing members 128 are arranged on both sides of the holder 104 in the axial direction A. Therefore, the holder 104 is sandwiched in the axial direction A by a pair of reinforcing members 128.

[0039] Each reinforcing member 128 is in the shape of a flat bar that is long in the first direction B, and is arranged such that two main surfaces face the axial direction A. Therefore, one of the main surfaces faces the holder 104 side. The reinforcing member 128 has a first groove portion 134 on the main surface facing the holder 104 side, into which the side plate 112 fits. The edge portion of the side plate 112 in the axial direction A fits into the first groove portion 134. Since the side plate 112 in the present embodiment is a corrugated plate, the first groove portion 134 is corrugated.

[0040] Furthermore, the reinforcing member 128 in the present embodiment has a second groove portion 136 on the main surface facing the holder 104 side, into which a pair of protruding portions 114 fit. Note that the reinforcing member 128 may not have the second groove portion 136. The edge portion of the protruding portion 114 in the axial direction A fits into the second groove portion 136. The second groove portion 136 extends in the second direction C from both end portions of the first groove portion 134 in the first direction B. A part of the second groove portion 136 has two protruding portions 114 fitted therein. Specifically, the tip end portion 114a of one holder 104 and the base end portion 114b of the other holder 104 in two adjacent holders 104 in the second direction C are fitted.

[0041] Also, the first groove portion 134 and the second groove portion 136 in the present embodiment are connected to each other. As an example, the second groove portion 136 is connected to the end portion of the first groove portion 134 in the first direction B. With this configuration, the corner portion, which is the connection portion between the side plate 112 and the protruding portion 114 in the holder 104, can be accommodated in the groove portion. As a result, the holder 104 can be held more firmly. Note that the second groove portion 136 may not be connected to the first groove portion 134.

[0042] Also, although each protruding portion 114 of the present embodiment has a uniform dimension in the axial direction A, it is not limited to this configuration. For example, the tip portion 114a of each protruding portion 114 may have one or both ends in the axial direction A notched. With this configuration, the protruding portion 114 that fits into the second groove portion 136 can be limited to only those of the holder 104 in which the side plate 112 is fitted into the first groove portion 134 of the reinforcing member 128 provided with the second groove portion 136. That is, one protruding portion 114 can fit into any second groove portion 136. Thereby, regardless of the position of the holder 104 with respect to the power storage module 100, that is, whether it is a holder 104 arranged at the end in the second direction C or a holder 104 arranged on the center side in the second direction C, the shape of the groove provided in the holder 104 can be unified. Note that, as an example, the dimension of the tip portion 114a with the end in the axial direction A notched in the axial direction A is equal to the distance between two reinforcing members 128 sandwiching the holder 104 in the axial direction A.

[0043] Further, the reinforcing member 128 has insulation properties and has a mounting portion 138 for the bus bar 108. That is, the reinforcing member 128 also serves as an insulating plate that supports the bus bar 108. The mounting portion 138 is provided on the main surface facing the opposite side of the holder 104 of the reinforcing member 128. The mounting portion 138 is, for example, a recess formed on the main surface and adapted to the shape of the bus bar 108. As an example, the depth of the mounting portion 138 is greater than the thickness of the bus bar 108. With this configuration, when the power storage module 100 abuts against surrounding members, it is possible to prevent the bus bar 108 from abutting against surrounding members. Note that the thickness of the bus bar 108 may be greater than the depth of the mounting portion 138. In this case, the portion of the bus bar 108 protruding from the mounting portion 138 may be covered with an insulating cap (not shown). The reinforcing member 128 is, for example, made of an insulating resin. Examples of the resin constituting the reinforcing member 128 include thermoplastic resins such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and Noryl (registered trademark) resin (modified PPE); and carbon fiber reinforced plastic (CFRP).

[0044] The power storage device 1 held by the holder 104 is arranged in the second direction C, and the reinforcing members 128 are fitted on both sides of each holder 104 in the axial direction A in a state where adjacent holders 104 are connected. And the bus bar 108 is mounted on at least a part of the mounting portion 138. The bus bar 108 is a strip-shaped conductive member extending in the first direction B, and the first electrode lead 8 and the second electrode lead 10 of each power storage device 1 are electrically connected to the bus bar 108. Thereby, a plurality of electrode bodies 2 are electrically connected. For example, each electrode lead is joined to the bus bar 108 by a known joining process such as laser welding. By interposing the reinforcing member 128 between the power storage device 1 and the bus bar 108, it is possible to suppress the electrical connection between the power storage device 1 and the bus bar 108 at portions other than the electrode leads.

[0045] In the present embodiment, a plurality of first electrode leads 8 project to the same side in each power storage device 1. Also, the postures of two adjacent power storage devices 1 are determined such that the first electrode leads 8 project to the same side. For this reason, when each electrode lead is joined to the bus bar 108, all the electrode bodies 2 are connected in parallel to each other. Note that the mode 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 the adjacent first electrode leads 8 and second electrode leads 10 may be electrically connected. That is, in each power storage device 1, a plurality of electrode bodies 2 may be connected in series. Also, two adjacent power storage devices 1 may be connected in series. Further, all the electrode bodies 2 mounted on the power storage module 100 may be connected in series.

[0046] Also, the first electrode lead 8 and the second electrode lead 10 may project to the same side of each other in the axial direction A. Thereby, it is possible to electrically connect each electrode body 2 only by arranging the bus bar 108 on only one side of the power storage module 100. Therefore, the number of man-hours for assembling the power storage module 100 can be reduced.

[0047] As described above, the power storage module 100 according to the present embodiment includes a power storage device 1, a holder 104 that holds the power storage device 1, and a reinforcing member 128 of the holder 104. The power storage device 1 includes a plurality of cylindrical electrode bodies 2, a plurality of accommodating portions 12 that individually wrap the plurality of electrode bodies 2, and a film exterior body 4 that seals each accommodating portion 12 and connects the plurality of accommodating portions 12 to each other. The holder 104 has a side plate 112 that extends in the arrangement direction (first direction B) of the plurality of electrode bodies 2, and the side plate 112 has a plurality of recesses 112a into which the accommodating portions 12 are fitted side by side in the first direction B. The reinforcing member 128 extends in the first direction B and is arranged beside the holder 104 in the axial direction A of the electrode body 2, and has a first groove portion 134 into which the side plate 112 is fitted on the surface facing the holder 104 side.

[0048] The power storage device 1 is long in the first direction B, and the film exterior body 4 has high flexibility. For this reason, when the power storage device 1 receives an impact or the like from the outside, the central portion in the first direction B is likely to bend so as to protrude in the second direction C with respect to both end portions. Further, since the power storage device 1 is long in the first direction B, the side plate 112 is also long in the first direction B. Further, from the viewpoint of weight reduction of the power storage module 100 and the like, it is required to make the thickness of the holder 104 as thin as possible. Therefore, it is difficult to give the holder 104 rigidity sufficient to sufficiently suppress the bending of the power storage device 1 described above.

[0049] On the other hand, by fitting the reinforcing member 128 into the end portion of the side plate 112, the rigidity of the holder 104 against the above-described bending can be increased. Therefore, the holding strength of the power storage device 1 can be increased. Further, the stress generated in the holder 104 can be effectively reduced, and the rigidity of the power storage module 100 can be increased.

[0050] In addition, the present inventor has confirmed that increasing the holding strength of the power storage device 1 by increasing the thickness of the holder 104 can suppress the weight increase of the power storage module 100 more effectively than increasing the holding strength by the reinforcing member 128. That is, by increasing the rigidity of the holder 104 with the reinforcing member 128, it is possible to suppress the weight increase of the power storage module 100 compared to the case where the same rigidity is obtained by increasing the thickness of the holder 104.

[0051] In addition, the side plate 112 of the present embodiment has a plurality of recesses 112a, and each accommodating portion 12 fits into each recess 112a. Thereby, the power storage device 1 can be held more stably. Therefore, the electrical connection state between each power storage device 1 and the bus bar 108 can be held more stably, and damage or the like of each power storage device 1 can be further suppressed. Thus, the power generation performance and safety performance of the power storage module 100 can be improved. Further, since the film exterior body 4 has a pouch structure in which a plurality of electrode bodies 2 are sealed, the power storage module 100 can be reduced in weight compared to the case where each electrode body 2 is individually sealed with an exterior can.

[0052] In addition, the holder 104 of the present embodiment has a pair of protruding portions 114 that protrude from both ends of the side plate 112 in the first direction B in a direction intersecting the arrangement direction and the axial direction A. And the reinforcing member 128 has a second groove portion 136 into which the pair of protruding portions 114 fit on the surface facing the holder 104 side. Thereby, three sides on the same surface of the holder 104 can be fixed by the reinforcing member 128. Therefore, the rigidity of the holder 104 can be further increased, and the holding strength of the power storage device 1 can be further increased. In addition, the reinforcing member 128 of the present embodiment is disposed on both sides of the holder 104 in the axial direction A. Thereby, the holding strength of the power storage device 1 can be further increased.

[0053] In addition, the first groove portion 134 and the second groove portion 136 of the present embodiment are connected to each other. With this configuration, the corner portion, which is the connection portion between the side plate 112 and the protruding portion 114 in the holder 104, can be accommodated in the groove portion. Therefore, the holder 104 can be held more firmly.

[0054] Further, the reinforcing member 128 of the present embodiment has insulation properties and has a mounting portion 138 for the bus bar 108 that electrically connects the plurality of electrode bodies 2. Thereby, reinforcement of the holder 104 and insulation of the bus bar 108 can be realized with one member. Therefore, an increase in the number of parts of the power storage module 100 due to the provision of the reinforcing member 128 can be suppressed.

[0055] Also, the power storage module 100 of the present embodiment includes a plurality of power storage devices 1. The side plate 112 has a corrugated shape with concavities and convexities repeating in the first direction B, is sandwiched between two power storage devices 1, and each housing portion 12 of one power storage device 1 fits into each concave portion 112a when viewed from one main surface side, and each housing portion 12 of the other power storage device 1 fits into each convex portion 112b when viewed from the main surface side from the back surface side. Thereby, the stability of each power storage device 1 in the power storage module 100 can be further enhanced.

[0056] Also, the film exterior body 4 of the present embodiment refracts or bends between adjacent housing portions 12 and extends in a zigzag manner. Thereby, the length of the power storage device 1 can be made shorter compared to the case where the film exterior body 4 is not folded without reducing the sealing portion 14. As a result, the number of electrode bodies 2 mounted on the power storage module 100 can be increased, or the power storage module 100 can be miniaturized without reducing the number of electrode bodies 2 mounted. That is, according to the present embodiment, it is possible to improve the energy density of the power storage module 100 while suppressing a decrease in the sealing performance of the electrode body 2.

[0057] The embodiments of the present disclosure have been described in detail above. The above-described embodiments are merely specific examples for implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design changes such as component changes, additions, deletions, etc. are possible without departing from the inventive concept defined in the claims. The new embodiments with design changes have the effects of the combined embodiments and deformations respectively. In the above embodiments, regarding the content where such design changes are possible, notations such as "in the present embodiment" and "in the present embodiment" are added for emphasis, but design changes are also allowed for the content without such notations. Also, any combination of the components included in each embodiment is effective as an aspect of the present disclosure. The hatching attached to the cross-section of the drawing does not limit the material of the hatched object.

[0058] (Modification example) This modification example has a configuration common to the embodiment except for the shape of the reinforcing member 128. Hereinafter, the modification example will be described centering on the configuration different from the embodiment, and the description of the common configuration will be omitted. FIG. 8 is a perspective view of a part of the power storage module 100 according to the modification example. In FIG. 8, the illustration of the power storage device 1 is simplified. Also, the illustration of the bus bar 108 is omitted.

[0059] As shown in FIG. 8, the reinforcing member 128 included in the power storage module 100 according to the modification example has a main body portion 140 and a pair of arm portions 142. The main body portion 140 corresponds to the reinforcing member 128 in the embodiment, is in the shape of a flat bar, and extends in the first direction B at a position overlapping the side plate 112 in the axial direction A. A first groove portion 134 and a second groove portion 136 are provided on the surface facing the holder 104 side.

[0060] A pair of arm portions 142 protrude from both ends of the main body portion 140 in the first direction B toward the second direction C and overlap the protruding portion 114 in the axial direction A. Therefore, when viewed from the axial direction A, the reinforcing member 128 has a substantially U-shaped form that is long in the first direction B. Each second groove portion 136 extends from the main body portion 140 to the tip of each arm portion 142. Thereby, the contact area between the second groove portion 136 and the protruding portion 114 can be increased. As a result, the rigidity of the holder 104 can be further enhanced, so that the holding strength of the power storage device 1 can be further enhanced.

Explanation of Signs

[0061] 1 Power storage device, 2 Electrode body, 4 Film exterior body, 12 Accommodating portion, 14 Sealing portion, 100 Power storage module, 104 Holder, 108 Bus bar, 112 Side plate, 112a Recess, 112b Projection, 114 Protruding portion, 128 Reinforcing member, 134 First groove portion, 136 Second groove portion, 138 Mounting portion.

Claims

1. A power storage device, a holder for holding the power storage device, and a reinforcing member of the holder, wherein the power storage device includes a plurality of cylindrical electrode bodies, a plurality of accommodating portions individually wrapping the plurality of electrode bodies, and a film exterior body having a sealing portion for sealing each accommodating portion and connecting the plurality of accommodating portions to each other, the holder has a side plate extending in the arrangement direction of the plurality of electrode bodies, and the side plate has a plurality of concave portions in which the accommodating portions are fitted side by side in the arrangement direction, the reinforcing member extends in the arrangement direction and is arranged side by side with the holder in the axial direction of the electrode body, and has a first groove portion on a surface facing the holder side into which the side plate is fitted, a power storage module.

2. The holder has a pair of protruding portions protruding from both ends of the side plate in the arrangement direction in a direction intersecting the arrangement direction and the axial direction, and the reinforcing member has a second groove portion on a surface facing the holder side into which the pair of protruding portions are fitted, The power storage module according to claim 1.

3. The first groove portion and the second groove portion are connected to each other, The power storage module according to claim 2.

4. The reinforcing member is arranged on both sides of the holder in the axial direction, The power storage module according to any one of claims 1 to 3.

5. The reinforcing member has insulation properties and has a mounting portion for a bus bar for electrically connecting the plurality of electrode bodies, The power storage module according to any one of claims 1 to 4.

6. The power storage module includes a plurality of the power storage devices, the side plate is in a corrugated shape repeating unevenness in the arrangement direction and is sandwiched between two of the power storage devices, each accommodating portion of one of the power storage devices is fitted into each concave portion when viewed from one main surface side, and each accommodating portion of the other power storage device is fitted from the back surface side into each convex portion when viewed from the main surface side, The power storage module according to any one of claims 1 to 5.

7. The film exterior body is refracted or curved between adjacent accommodating portions and extends in a zigzag pattern, The power storage module according to any one of claims 1 to 6.

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