JP6874646B2 - Batteries - Google Patents

Description

The present disclosure relates to an assembled battery.

In a conventional assembled battery, a technique for cooling the battery with a refrigerant passing through a refrigerant pipe is disclosed in, for example, Japanese Patent Application Laid-Open No. 2009-134938 (Patent Document 1).

JP-A-2009-134938

In the case of the assembled battery disclosed in Patent Document 1, a pipe for flowing the refrigerant is required, and the weight of the assembled battery becomes large.

In addition, large-sized assembled batteries aimed at increasing the capacity for plug-in hybrid vehicles or electric vehicles are often mounted under the floor of the vehicle, so that the lower part of the assembled batteries may be loaded from the road surface. Therefore, it is necessary to improve the rigidity of the lower part of the assembled battery.

The present disclosure provides an assembled battery capable of simplifying the cooling structure while improving the rigidity.

The assembled battery according to the present disclosure includes a plurality of secondary batteries, a bottom plate, a side wall, and reinforce. A plurality of secondary batteries are stacked with a gap. A plurality of secondary batteries are mounted on the bottom plate. The bottom plate includes a flat plate-shaped upper plate, a flat plate-shaped lower plate, and an intermediate material made of foamed resin. The intermediate material is filled between the upper plate and the lower plate. The side wall is arranged so as to surround the plurality of secondary batteries. Reinforce extends in the stacking direction of multiple secondary batteries. Both ends of the reinforce are connected to the inner peripheral surface of the side wall. The intermediate material is formed with recesses in which the surface in contact with the upper plate is recessed in a groove shape. The recess extends in the depth direction orthogonal to the stacking direction and the thickness direction of the intermediate material. The upper plate is formed with a through hole that penetrates the upper plate in the thickness direction and communicates the recess and the gap. A first hollow space is formed inside the reinforce. The reinforce has a communication hole that opens on the surface facing the secondary battery and communicates the gap and the first hollow space. Inside the side wall, a second hollow space that communicates with the first hollow space is formed. The refrigerant that cools the plurality of secondary batteries flows through the recess, the through hole, the gap, the communication hole, the first hollow space, and the second hollow space in this order.

According to the above-mentioned assembled battery, the rigidity of the lower part of the assembled battery is improved by mounting a plurality of secondary batteries on the bottom plate. Since the recess formed in the intermediate material of the bottom plate functions as a cold air passage, it is not necessary to separately use piping to form the cold air passage. Therefore, the cooling structure of the assembled battery can be simplified while improving the rigidity of the lower part of the assembled battery.

According to the present disclosure, it is possible to realize an assembled battery capable of simplifying the cooling structure while improving the rigidity.

It is a top view of the assembled battery according to Embodiment 1. FIG. It is sectional drawing of the assembled battery along the line II-II shown in FIG. It is sectional drawing of the assembled battery along the line III-III shown in FIG. It is a perspective view of the intermediate material according to Embodiment 1. FIG. It is an enlarged view of a part of the cross section of the intermediate material along the VV line shown in FIG. It is a top view explaining the flow path of a cold air inside a bottom plate. It is a top view explaining the flow path of the cold air from a bottom plate to a discharge port. It is sectional drawing of the assembled battery along the line VIII-VIII shown in FIG. It is a top view of the intermediate material according to Embodiment 2. It is an enlarged view of the region X shown in FIG. It is sectional drawing of the assembled battery according to Embodiment 3. FIG. It is sectional drawing of the assembled battery according to Embodiment 4. FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are given the same reference numbers, and the description thereof will not be repeated.

[Embodiment 1]
(Assembled battery 1)
FIG. 1 is a plan view of the assembled battery 1 according to the first embodiment. The assembled battery 1 is mounted on a hybrid vehicle. The assembled battery 1 is used as a power source for a hybrid vehicle together with an internal combustion engine such as a gasoline engine or a diesel engine. The assembled battery 1 is arranged under the floor of the vehicle. As another example, the assembled battery 1 is mounted on an electric vehicle or a fuel cell vehicle.

As shown in FIG. 1, the assembled battery 1 includes a plurality of battery modules 20, a side wall 7, and a plurality of reinforces 8. The battery module 20 includes a laminated body 20a (a dotted line in FIG. 1) composed of the laminated secondary batteries 2. The battery module 20 is composed of laminated bodies 20a arranged in two rows. The assembled battery 1 includes eight battery modules 20.

The side wall 7 is arranged so as to surround the plurality of battery modules 20. The side wall 7 has a substantially rectangular shape with chamfered corners in a plan view. The side wall 7 has a front edge portion 7e, a side edge portion 7f, and a trailing edge portion 7g. The side edge portion 7f has a shape extending in the depth direction DR3 described later.

A front edge portion 7e is provided at one end of the side edge portion 7f. The side of the side wall 7 where the front edge portion 7e is provided is the front side of the vehicle on which the assembled battery 1 is mounted. A trailing edge 7g is provided at the other end of the side edge 7f. The side of the side wall 7 where the trailing edge portion 7g is provided is the rear side of the vehicle on which the assembled battery 1 is mounted. A discharge port 7h through which a refrigerant described later is discharged is formed in the trailing edge portion 7g.

The stacking direction DR1 indicated by the double-headed arrow in the figure is the direction in which the plurality of secondary batteries 2 are stacked, and is the left-right direction in FIG. The depth direction DR3 is the direction in which the laminated bodies 20a are arranged in two rows, and is the vertical direction in FIG. The depth direction DR3 is orthogonal to the stacking direction DR1. The assembled battery 1 is arranged so that the depth direction DR3 is along the front-rear direction of the vehicle.

The reinforce 8 is arranged so as to sandwich the battery module 20. The plurality of reinforcements 8 are arranged side by side in the depth direction DR3. The reinforce 8 extends in the stacking direction DR1. Both ends of the reinforce 8 in the stacking direction DR1 are connected to the inner peripheral surface of the side wall 7. The reinforce 8 reinforces the side wall 7.

FIG. 2 is a cross-sectional view of the assembled battery 1 along the line II-II shown in FIG. FIG. 3 is a cross-sectional view of the assembled battery 1 along the line III-III shown in FIG.

As shown in FIGS. 2 and 3, a gap 2a is formed between the adjacent secondary batteries 2. The plurality of secondary batteries 2 are stacked with a gap 2a. The secondary battery 2 has a substantially rectangular box-shaped outer shape. The secondary battery 2 has a pair of side surfaces 2b and a pair of narrow surfaces 2c.

The side surface 2b is a side surface of the secondary battery 2 having a large area. The side surface 2b faces the side surface 2b of the adjacent secondary battery 2. The side surface 2b of the secondary battery 2 at the end of the laminate 20a (FIG. 1) faces the side wall 7. The narrow surface 2c is a surface having a small area among the side surfaces of the secondary battery 2. One of the pair of narrow surfaces 2c faces the reinforce 8. The other of the pair of narrow surfaces 2c faces the other of the pair of narrow surfaces 2c in the secondary battery 2 included in the adjacent laminate 20a.

The assembled battery 1 includes a bottom plate 3. The plurality of secondary batteries 2 are mounted on the bottom plate 3. The plurality of secondary batteries 2 are placed on the bottom plate 3. The bottom plate 3 includes a flat plate-shaped upper plate 4, a flat plate-shaped lower plate 6, and an intermediate material 5 made of foamed resin. The intermediate material 5 is filled between the upper plate 4 and the lower plate 6. The bottom plate 3 is a so-called sandwich panel in which an intermediate material 5 which is a foaming material is sandwiched between an upper plate 4 and a lower plate 6 which are metal plates.

The thickness direction DR2 indicated by the double-headed arrow extending in the vertical direction in FIGS. 2 and 3 is the thickness direction of the bottom plate 3, that is, the thickness direction of each of the upper plate 4, the lower plate 6, and the intermediate member 5. The thickness direction DR2 is a direction orthogonal to the stacking direction DR1 and orthogonal to the depth direction DR3. The assembled battery 1 is arranged so that the thickness direction DR2 is along the vertical direction (vertical direction).

FIG. 4 is a perspective view of the intermediate member 5 according to the first embodiment. FIG. 5 is an enlarged view of a part of the cross section of the intermediate member 5 along the VV line shown in FIG. The intermediate material 5 has a front surface 5b and a back surface 5c. The surface 5b is in contact with the upper plate 4. The intermediate material 5 is formed with a plurality of recesses 5a in which the surface 5b is recessed in a groove shape. The plurality of recesses 5a are formed side by side in the stacking direction DR1. The recess 5a extends in the depth direction DR3.

As shown in FIG. 2, the upper plate 4 is provided so as to cover the recess 5a. The upper plate 4 is installed on the surface 5b of the intermediate material 5. A plurality of through holes 4a are formed in the upper plate 4. The through hole 4a penetrates the upper plate 4 in the thickness direction DR2. The through hole 4a communicates the recess 5a with the gap 2a. The plurality of through holes 4a are formed side by side in the stacking direction DR1.

The lower plate 6 is provided on the back surface 5c of the intermediate material 5. The lower plate 6 is in contact with the intermediate material 5. The lower plate 6 is provided below the assembled battery 1. The lower plate 6 is provided in the lowermost direction of the assembled battery 1. The lower plate 6 is arranged at a position closest to the road surface among the assembled batteries 1 arranged under the floor of the vehicle.

The cross-sectional view of the side edge portion 7f has an upper portion 7b, a lower portion 7c, and a partition portion 7d. The upper portion 7b and the lower portion 7c are integrally provided. The lower portion 7c is sandwiched between the upper plate 4 and the lower plate 6. The upper portion 7b projects upward from the lower portion 7c. A second hollow space 7a is formed inside the upper portion 7b. Inside the upper portion 7b, a partition portion 7d is provided so as to partition the second hollow space 7a up and down.

The assembled battery 1 further includes a spacer 9. The spacer 9 is an insulating material. As shown in FIG. 2, the spacer 9 has an upper end portion 9a and a protruding portion 9g. The upper end portion 9a is provided on the upper side of the secondary battery 2. The protruding portion 9g projects downward from the upper end portion 9a. A gap 2a is formed by providing the protruding portion 9g between the adjacent secondary batteries 2.

As shown in FIG. 3, the spacer 9 further includes a side wall portion 9e, a lower end portion 9b, a first partition portion 9c, and a second partition portion 9d. The side wall portion 9e covers the other of the pair of narrow surfaces 2c. The side wall portion 9e is interposed between the two laminated bodies 20a (FIG. 1) included in the battery module 20 to insulate the two laminated bodies 20a from each other. The side wall portion 9e is connected to the upper end portion 9a. The side wall portion 9e extends in the thickness direction DR2.

The lower end portion 9b is provided on the lower side of the secondary battery 2. The first partition portion 9c projects upward from the lower end portion 9b toward the upper end portion 9a. The second partition portion 9d projects downward from the upper end portion 9a toward the lower end portion 9b. The first partition 9c is provided closer to the other of the pair of narrow surfaces 2c than the second partition 9d, and thus closer to the side wall 9e.

The second partition portion 9d is provided closer to one of the pair of narrow surfaces 2c than the first partition portion 9c, and therefore closer to the reinforce 8. The first partition 9c and the second partition 9d extend in the thickness direction DR2 along the side surface 2b. An outlet 9f is formed between the second partition 9d and the lower end 9b. The spacer 9 is provided so as not to block the through hole 4a. As a result, the through hole 4a ensures communication between the recess 5a and the gap 2a.

The reinforce 8 is installed on the upper plate 4. The cross-sectional view of the reinforcement 8 has a substantially rectangular shape. A first hollow space 8a is formed inside the reinforce 8. The first hollow space 8a is open at both ends of the reinforce 8. An opening is formed in a portion of the side wall 7 where the side wall 7 and the reinforce 8 are connected. As a result, the first hollow space 8a communicates with the second hollow space 7a formed inside the side wall 7. The reinforce 8 has a facing surface 8c. The facing surface 8c is a surface facing the plurality of secondary batteries 2. The facing surface 8c faces one of the pair of narrow surfaces 2c of the secondary battery 2.

A plurality of communication holes 8b are formed in the reinforce 8. The plurality of communication holes 8b are formed side by side in the thickness direction DR2. The communication hole 8b penetrates the wall surface of the reinforce 8 provided with the facing surface 8c in the depth direction DR3. The communication hole 8b is open to the facing surface 8c. The communication hole 8b communicates the gap 2a with the first hollow space 8a.

As shown in FIG. 1, a chamber portion 10 is provided inside the bottom plate 3. The chamber portion 10 is provided on the front side of the vehicle. The chamber portion 10 communicates with the recess 5a inside the bottom plate 3. The chamber portion 10 is provided with a refrigerant introduction port 11. A refrigerant is introduced into the chamber portion 10 from a refrigerant supply device (not shown) via the refrigerant introduction port 11. In the first embodiment, the refrigerant is air (cold air). The cold air introduced from the refrigerant supply device cools the plurality of secondary batteries 2.

(Cold air flow path)
FIG. 6 is a plan view illustrating a flow path of cold air inside the bottom plate 3. FIG. 7 is a plan view illustrating a flow path of cold air from the bottom plate 3 to the discharge port 7h. FIG. 8 is a cross-sectional view of the assembled battery 1 along the line VIII-VIII shown in FIG. The flow path of the cold air flowing from the chamber portion 10 will be described with reference to FIGS. 6 to 8.

The cold air introduced into the chamber portion 10 flows into the recess 5a. The cold air flowing into the recess 5a flows toward the trailing edge portion 7g in the depth direction DR3 (the direction of the dotted arrow in FIG. 6 and the direction of the white arrow in FIG. 8). On the way to the trailing edge portion 7g, the cold air flows into the gap 2a of each secondary battery 2 through the through holes 4a formed side by side in the depth direction DR3.

The cold air that has flowed into the gap 2a from the through hole 4a passes between the side wall portion 9e and the first partition portion 9c toward the upper end portion 9a. After that, the cold air passes between the upper end portion 9a and the first partition portion 9c, and passes between the first partition portion 9c and the second partition portion 9d toward the lower end portion 9b. After that, the cold air passes through the plurality of communication holes 8b from the outlet 9f. In this way, the cold air flows through the flow path formed by the spacer 9. The cold air flows along the side surface 2b of the secondary battery 2, so that the secondary battery 2 that has generated heat due to charging or the like is cooled.

The cold air that has passed through each gap 2a and has absorbed the heat generated from each secondary battery 2 flows into the first hollow space 8a through the plurality of communication holes 8b and merges. The cold air merged in the first hollow space 8a flows in the first hollow space 8a toward the side edge portion 7f. The cold air merged at the side edge portion 7f flows in the second hollow space 7a toward the trailing edge portion 7g. After that, the cold air is discharged from the discharge port 7h. Cold air is discharged to the outside through a filter (not shown).

In this way, the cold air flows through the chamber portion 10, the recess 5a, the through hole 4a, the gap 2a, the communication hole 8b, the first hollow space 8a, and the second hollow space 7a in this order.

(Action effect)
Since the assembled battery 1 according to the first embodiment is mounted under the floor of the vehicle, the lower portion of the assembled battery 1 may receive a load from the road surface. In order to improve the durability of the assembled battery 1, as shown in FIG. 2, a plurality of secondary batteries 2 are mounted on the bottom plate 3 to improve the rigidity of the lower portion of the assembled battery 1. Further, a recess 5a is formed in the intermediate material 5, and cold air is blown from the recess 5a into the gap 2a through the through hole 4a to cool the secondary battery 2. By forming a cold air passage (passage for cold air in the assembled battery 1) composed of recesses 5a inside the bottom plate 3, it is not necessary to separately use piping to form the cold air passage. Thereby, the cooling structure of the assembled battery 1 can be simplified.

In a large assembled battery, a lot of heat is generated during quick charging. In the case of air cooling (cold air) cooling, the ability to cool the secondary battery (cooling capacity) is insufficient, the temperature rise of the secondary battery cannot be suppressed, and the life of the secondary battery may be shortened. In order to secure the cooling capacity, it is preferable to provide a heat insulating material in the portion of the cold air passage that is in contact with the outside air, or to blow a certain amount of cold air on the secondary battery to uniformly cool the secondary battery.

As shown in FIG. 2, the cold air passage formed of the recesses 5a is not in contact with the lower plate 6 because the surface 5b of the foamed resin intermediate material 5 is formed by being recessed in a groove shape. As a result, the heat transferred from the outside air to the lower plate 6 is transferred to the cold air passage, and the temperature of the cold air passage can be suppressed from rising. Therefore, the heat insulating property of the cold air passage can be ensured.

The recess 5a extends in the depth direction DR3. A plurality of recesses 5a are arranged in the stacking direction DR1. The chamber portion 10 and the recess 5a communicate with each other inside the bottom plate 3. Cold air is supplied to the plurality of recesses 5a through the chamber portion 10. The cold air supplied to the plurality of recesses 5a passes through the through holes 4a corresponding to each of the plurality of recesses 5a, flows into each gap 2a, and flows along the side surface 2b of each secondary battery 2. As a result, the plurality of secondary batteries 2 can be uniformly cooled.

[Embodiment 2]
FIG. 9 is a plan view of the intermediate member 5 according to the second embodiment. FIG. 10 is an enlarged view of the region X shown in FIG. The intermediate member 5 according to the second embodiment has a plurality of columns 5d. The support column 5d has a columnar shape. The plurality of columns 5d are arranged side by side at intervals in the stacking direction DR1. The plurality of columns 5d are arranged side by side at intervals in the depth direction DR3. The plurality of columns 5d are arranged side by side at intervals in the direction of inclination with respect to the stacking direction DR1 and the depth direction DR3.

A recess 5a is formed between the plurality of columns 5d. The recess 5a according to the second embodiment is formed in a mesh shape. In the second embodiment, the recesses 5a formed in a mesh shape form a cold air passage.

Since the plurality of columns 5d are arranged side by side at intervals in three directions, the effective cross-sectional area of the cold air passage (the area where cold air can actually flow in the cold air passage) becomes large. As a result, the pressure loss in the cold air passage can be reduced.

By reducing the pressure loss in the recess 5a (cold air passage), the flow rate of the cold air flowing from the recess 5a into the through hole 4a is made uniform. As a result, the cold air can be efficiently distributed to the gap 2a of the secondary battery 2. Therefore, the plurality of secondary batteries 2 can be efficiently cooled.

The recess 5a according to the first embodiment extends in the depth direction DR3. When the recess 5a extends in one direction, the difference in rigidity of the bottom plate 3 depending on the direction of the load is large. For example, in the first embodiment, the rigidity of the bottom plate 3 when a force is applied to the stacking direction DR1 is relatively small, and the rigidity of the bottom plate 3 when a force is applied to the depth direction DR3 is relatively large. On the other hand, in the second embodiment, since the columns 5d are arranged two-dimensionally and the recesses 5a are formed in a mesh shape, the difference in rigidity depending on the direction of the load is small. As a result, the rigidity of the bottom plate 3 is improved.

As described above, by providing the intermediate member 5 with the plurality of columns 5d, the rigidity of the lower portion of the assembled battery 1 can be improved while maintaining a simple cooling structure.

In addition, a plurality of columns 5d as shown in FIG. 10 may be provided in the chamber portion 10. In the embodiment, a plurality of columns 5d may be provided on at least one of the intermediate member 5 and the chamber portion 10.

[Embodiment 3]
FIG. 11 is a cross-sectional view of the assembled battery 1 according to the third embodiment. Compared to the assembled battery 1 according to the first embodiment, the assembled battery 1 according to the third embodiment further includes an insulating material 12 having high thermal conductivity. The insulating material 12 is arranged between the upper plate 4 and the secondary battery 2. The insulating material 12 insulates the secondary battery 2 and the upper plate 4. The secondary battery 2 has a bottom surface 2d. The bottom surface 2d is in surface contact with the insulating material 12.

A metal having good thermal conductivity is used for the upper plate 4. The upper plate 4 is in surface contact with the insulating material 12. The upper plate 4 faces the cold air passage (recess 5a). The upper plate 4 cooled by the cold air passing through the recess 5a cools the insulating material 12. The insulating material 12 cooled by the upper plate 4 cools the bottom surface 2d.

In addition to cooling the side surface 2b of the secondary battery 2 by passing cold air through the gap 2a, the cooling capacity can be improved by cooling the bottom surface 2d with the cooled insulating material 12.

Fins 13 are provided on the upper plate 4. The fins 13 project downward from the upper plate 4 toward the lower plate 6 in the thickness direction DR2. The fin 13 is provided in the recess 5a. Since the fin 13 has a large contact area with the cold air flowing through the recess 5a, it is easily cooled. The fin 13 is cooled by the cold air flowing through the recess 5a, so that the upper plate 4 is easily cooled. Thereby, the cooling capacity can be further improved.

[Embodiment 4]
FIG. 12 is a cross-sectional view of the assembled battery 1 according to the fourth embodiment. The communication hole 8b1, the communication hole 8b2, and the communication hole 8b3 are formed in the reinforce 8 according to the fourth embodiment. The communication hole 8b1 is formed at the lowermost part closest to the outlet 9f. The communication hole 8b3 is formed at the uppermost portion farthest from the outlet 9f. The communication hole 8b2 is formed between the communication hole 8b1 and the communication hole 8b3 in the thickness direction DR2.

The communication hole 8b1 has a smaller diameter than the communication hole 8b2. The communication hole 8b2 has a smaller diameter than the communication hole 8b3. Further, the exhaust path connecting from the exhaust port 7h to the outside is depressurized, so that cold air can easily flow through the cold air passage from the chamber portion 10 to the discharge port 7h.

If the shapes of the plurality of communication holes 8b are the same, the cold air flowing into the first hollow space 8a from the outlet 9f easily passes through the lowermost communication hole 8b closest to the outlet 9f. By making the diameter of the communication hole 8b1 smaller than the diameter of the communication hole 8b2 and the communication hole 8b3, the amount of cold air passing through the communication hole 8b1 (the amount of cold air passing through a cross section per unit time, the same applies hereinafter) becomes smaller. .. Therefore, the amount of cold air passing through the communication holes 8b2 and the communication holes 8b3 formed at a distance from the outlet 9f is larger than that of the communication holes 8b1. By making the diameter of the communication hole 8b2 smaller than the diameter of the communication hole 8b3, the amount of cold air passing through the communication hole 8b2 becomes smaller. Therefore, the amount of cold air passing through the communication hole 8b3 formed at a distance from the outlet 9f is larger than that of the communication hole 8b2.

Further, the cold air flows along the side surface 2b through the cold air passage formed by the spacer 9.

In the flow of cold air from the second partition portion 9d to the first hollow space 8a, the cold air easily flows through the communication holes 8b2 and the communication holes 8b3 formed above from the outlet 9f below. As a result, cold air can uniformly flow into the first hollow space 8a in the thickness direction DR2. Therefore, since the cold air passes through the entire side surface 2b, the cooling capacity can be improved.

The facing surface 8c through which the plurality of communication holes 8b open faces the narrow surface 2c. The narrow surface 2c is cooled by the cold air passing between the narrow surface 2c and the reinforce 8. By cooling not only the side surface 2b but also the narrow surface 2c, the cooling capacity can be improved.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 set battery, 2 secondary battery, 2a gap, 2b side surface, 2c narrow surface, 2d bottom surface, 3 bottom plate, 4 top plate, 4a through hole, 5 intermediate material, 5a recess, 5b surface, 5c back surface, 5d strut, 6 Lower plate, 7 side walls, 7a second hollow space, 7b upper part, 7c lower part, 7d partition part, 7e front edge part, 7f side edge part, 7g trailing edge part, 7h outlet, 8 reinforce, 8a first hollow space, 8b communication hole, 8c facing surface, 9 spacer, 9a upper end, 9b lower end, 9c first partition, 9d second partition, 9e side wall, 9f outlet, 9g protrusion, 10 chamber, 11 refrigerant introduction Mouth, 12 insulation, 13 fins, 20 battery module, 20a laminate, DR1 stacking direction, DR2 thickness direction, DR3 depth direction.

Claims (1)

Multiple secondary batteries stacked with a gap,
It is provided with a bottom plate on which the plurality of secondary batteries are mounted.
The bottom plate includes a flat plate-shaped upper plate, a flat plate-shaped lower plate, and an intermediate material made of foamed resin filled between the upper plate and the lower plate.
Further, a side wall arranged so as to surround the plurality of secondary batteries, and
A reinforce that extends in the stacking direction of the plurality of secondary batteries and has both ends connected to the inner peripheral surface of the side wall.
The intermediate material is formed with recesses having a groove-like surface in contact with the upper plate, and the recesses extend in a depth direction orthogonal to the stacking direction and the thickness direction of the intermediate material.
The upper plate is formed with a through hole that penetrates the upper plate in the thickness direction and communicates the recess and the gap.
A first hollow space is formed inside the reinforce, and the reinforce is formed with a communication hole that opens on a surface facing the secondary battery and communicates the gap with the first hollow space.
Inside the side wall, a second hollow space communicating with the first hollow space is formed.
The refrigerant for cooling the plurality of secondary batteries flows through the recess, the through hole, the gap, the communication hole, the first hollow space, and the second hollow space in this order.

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