Battery Module

Abstract

To provide a battery module capable of securing both a restraining function and a cooling function for battery cells, and of downsizing a device.SOLUTION: A battery module comprises: a housing that has an accommodation space in which a plurality of battery cells are arranged in a laminate and accommodated; and a plurality of partition plates provided on the housing so as to partition the accommodation space into spaces for the plurality of individual battery cells at such an interval that each of the plurality of battery cells is sandwiched in the arrangement direction of the plurality of battery cells. Each of the plurality of partition plates comprises: a cooling flow channel penetrating in a crossing direction crossing the arrangement direction to circulate cooling medium; and an action part that applies a load to battery cells opposed to each other in the arrangement direction among the plurality of battery cells depending on a pressure of the cooling medium in the cooling flow channel and performs heat exchange between the battery cells and the cooling medium.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a battery module. [Background technology]

[0002] Conventionally, battery modules have been proposed that include a plurality of battery cells arranged adjacent to each other and constrained in the arrangement direction of the plurality of battery cells. For example, Patent Document 1 discloses a battery module (battery assembly) that includes a plurality of battery cells arranged in a predetermined direction, a buffer plate that is constrained together with the plurality of battery cells in a state in which a load is applied in the arrangement direction, and a cooling plate for cooling the plurality of battery cells.

[0003] In the battery module described in Patent Document 1, the buffer plate has a deformation portion that allows deformation of the battery cell in the thickness direction, and is arranged between the battery cells so as to be in contact with one end surface of the battery cell in the thickness direction. Such a buffer plate absorbs the expansion of the battery cell by deforming the deformation portion in accordance with the expansion of the battery cell in the thickness direction. The internal pressure of the deformation portion of the buffer plate is adjusted by a hydraulic pressure adjustment mechanism, and the load (surface pressure) applied to the battery cell is controlled to be kept constant based on the pressure measured by a pressure sensor between the battery cells. Meanwhile, the cooling plate is arranged between the battery cells so as to be in contact with the other end surface of the battery cell in the thickness direction (the surface opposite to the buffer plate). Such a cooling plate has a refrigerant supply path, and cools the battery cell by heat exchange between the refrigerant flowing through the supply path and the battery cell. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-157747 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the battery module described in the above-mentioned Patent Document 1, in order to ensure both the function of restraining the multiple battery cells with an appropriate load while absorbing deformation in the thickness direction of the battery cells (hereinafter referred to as the restraining function) and the function of cooling the restrained multiple battery cells (hereinafter referred to as the cooling function), it is necessary to arrange separate buffer plates and cooling plates alternately between the multiple battery cells. Therefore, spaces required for arranging the buffer plates and the cooling plates are required between the multiple battery cells, making it difficult to reduce the size of the battery module.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a battery module that ensures both a restraining function and a cooling function for the battery cells, while enabling the device size to be reduced. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the battery module of the present invention comprises a housing having a storage space in which a plurality of battery cells are arranged in a stacked manner, and a plurality of partition plates provided in the housing at intervals that sandwich each of the plurality of battery cells in the arrangement direction of the plurality of battery cells so as to separate the storage space for each of the plurality of battery cells, each of the plurality of partition plates comprising a cooling flow path that penetrates in a cross direction that crosses the arrangement direction and allows a refrigerant to flow, and an action portion that applies a load to a battery cell among the plurality of battery cells that faces the arrangement direction in accordance with the pressure of the refrigerant in the cooling flow path, and that performs heat exchange between the battery cell and the refrigerant.

[0008] In addition, the battery module of the present invention, in the above invention, is characterized in that it comprises a pump that sends the refrigerant to the cooling flow path through piping at a variable flow rate, a pressure sensor that detects the pressure between the battery cell and the refrigerant, and a control unit that causes the pump to adjust the flow rate of the refrigerant so that the pressure detected by the pressure sensor is within an allowable range for the battery cell.

[0009] In addition, the battery module of the present invention, in the above invention, further comprises an upstream valve provided in piping upstream of the cooling flow path in the flow direction of the refrigerant, and a downstream valve provided in piping downstream of the cooling flow path in the flow direction of the refrigerant, and the control unit monitors the operating state of the pump, and when the pump is stopped, controls the upstream valve and the downstream valve to close.

[0010] In addition, the battery module of the present invention is characterized in that, in the above invention, the action portion is arranged to protrude from each of the plate surfaces of the multiple partition plates in the arrangement direction, and the amount of protrusion increases and decreases in accordance with an increase or decrease in pressure of the refrigerant in the cooling flow path.

[0011] In the battery module according to the present invention, in the above invention, the cooling flow path is formed inside the action portion.

[0012] In the battery module according to the present invention, in the above invention, the cooling flow path is formed so that a cross section thereof is circular.

[0013] In the battery module according to the present invention, in the above invention, the plurality of partition plates are integrally formed with the housing. Effect of the Invention

[0014] The battery module according to the present invention has the advantage that it is possible to ensure both the restraining function and the cooling function for the battery cells, and to reduce the size of the device. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of a battery pack applied to a battery module according to an embodiment of the present invention. [Diagram 2]FIG. 2 is a top view showing one configuration example of a battery pack applied to the battery module according to the embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of the configuration of the battery pack shown in FIG. 2 taken along line AA. [Figure 4] FIG. 4 is a perspective view showing an example of a configuration of a battery cell in an embodiment of the present invention. [Diagram 5] FIG. 5 is a perspective view showing an example of the configuration of a casing of a battery pack according to an embodiment of the present invention. [Figure 6] FIG. 6 is a top view of the housing shown in FIG. [Figure 7] FIG. 7 is a schematic diagram showing an example of a configuration of a partition plate in an embodiment of the present invention. [Figure 8] FIG. 8 is a schematic cross-sectional view showing one configuration example of the partition plate shown in FIG. 7 taken along the line BB. [Figure 9] FIG. 9 is a schematic diagram showing an example of a change in state of the action portion of the partition plate in the embodiment of the present invention. [Figure 10] FIG. 10 is a perspective view showing an example of the configuration of the first chamber and the second chamber in an embodiment of the present invention. [Figure 11] FIG. 11 is an explanatory diagram illustrating the flow of the refrigerant in the battery pack according to the embodiment of the present invention. [Figure 12] FIG. 12 is a schematic diagram showing a configuration example of a battery module according to an embodiment of the present invention. [Figure 13] FIG. 13 is a flow chart showing an example of the operation of the battery module according to the embodiment of the present invention. [Figure 14] FIG. 14 is a schematic diagram showing an example of a countermeasure against thermal runaway of the battery cell 11 that can be taken by the battery module according to the embodiment of the present invention. [Figure 15] FIG. 15 is a schematic diagram showing a configuration example of a partition plate according to the first modified example of the present invention. [Figure 16] FIG. 16 is a schematic diagram showing a configuration example of a partition plate according to the second modification of the present invention. [Figure 17] FIG. 17 is a schematic diagram showing a configuration example of a partition plate according to the third modified example of the present invention. [Figure 18] FIG. 18 is a schematic diagram showing a configuration example of a partition plate according to the fourth modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, a preferred embodiment of the battery module according to the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment. It should be noted that the drawings are schematic, and the dimensional relationship between elements, the ratio of elements, and the like may differ from the actual ones. The drawings may also include parts with different dimensional relationships and ratios. In addition, the same components are denoted by the same reference numerals in each drawing.

[0017] (Battery pack) First, the configuration of a battery pack applied to a battery module according to an embodiment of the present invention will be described. FIG. 1 is a perspective view showing an example of a configuration of a battery pack applied to a battery module according to an embodiment of the present invention. FIG. 2 is a top view showing an example of a configuration of a battery pack applied to a battery module according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing an example of a configuration of the battery pack taken along line AA of FIG. 2. As shown in FIGS. 1 to 3, a battery pack 10 according to this embodiment includes a plurality of battery cells 11, a housing 20 that houses the plurality of battery cells 11, and a plurality of partition plates 30 that divide a housing space 29 of the housing 20. The battery pack 10 also includes a first chamber 40 provided with an inlet 41 for a refrigerant for cooling the plurality of battery cells 11, and a second chamber 50 provided with an outlet 51 for a refrigerant used to cool the plurality of battery cells 11.

[0018] As shown in Figs. 1 to 3, the multiple battery cells 11 are arranged in a stacked manner and accommodated in the accommodation space 29 of the housing 20. In this embodiment, the number of the battery cells 11 is, for example, six. Fig. 4 is a perspective view showing an example of a configuration of a battery cell in an embodiment of the present invention. As shown in Fig. 4, the battery cell 11 includes an exterior case 12, a lid portion 16, and a pair of electrode terminals 17, 18. The exterior case 12 is a bottomed box-shaped body having abdominal surface portions 13a, 13b, side surface portions 14a, 14b, and a bottom portion 15, and accommodates the internal electrodes, separators, and the like (not shown) that constitute the battery cell 11. In this exterior case 12, the abdominal surface portions 13a, 13b are end surface portions that face the thickness direction of the battery cell 11, and the side surface portions 14a, 14b are end surface portions that face the width direction of the battery cell 11. The areas of the abdominal surface portions 13a, 13b are larger than the side surface portions 14a, 14b and the bottom portion 15. The lid 16 is attached to the opening of the exterior case 12 by welding or the like to close the opening. A pair of electrode terminals 17, 18 is provided on the lid 16. For example, one of the pair of electrode terminals 17, 18 is a positive terminal, and the other is a negative terminal. Examples of materials constituting the exterior case 12, the lid 16, and the electrode terminals 17, 18 include metals such as aluminum.

[0019] As shown in Figs. 1 to 3, such battery cells 11 are arranged so that abdominal surface portions 13a, 13b face each other in the thickness direction of the battery cells 11, and are accommodated in a plurality of portions in the accommodation space 29 of the housing 20. That is, the arrangement direction D1 of the stacked battery cells 11 is the same as the thickness direction of the battery cells 11. In addition, in this embodiment, the width direction D2 of the battery pack 10 is the same as the width direction of the battery cells 11 in a state where the battery pack 10 is accommodated in the housing 20. The height direction D3 of the battery pack 10 is a direction perpendicular to the arrangement direction D1 and the width direction D2 described above, and is the same as, for example, the height direction of the battery cells 11 in a state where the battery pack 10 is accommodated in the housing 20. The arrangement direction D1, the width direction D2, and the height direction D3 described above are the same for each component of the battery pack 10.

[0020] The housing 20 accommodates a plurality of battery cells 11. FIG. 5 is a perspective view showing an example of the configuration of the housing of the battery pack according to the embodiment of the present invention. FIG. 6 is a top view of the housing shown in FIG. 5. In detail, as shown in FIGS. 5 and 6, the housing 20 has a bottom 21 and a pair of side portions 22, 23, and is a bottomed U-shaped body with an opening on the upper side in the height direction D3. Of the pair of side portions 22, 23, one side portion 22 is provided at one end of the bottom 21 in the width direction D2, and the other side portion 23 is provided at the other end of the bottom 21 in the width direction D2. As shown in FIG. 5, the side portion 23 has an opening 23a that communicates with each of the cooling channels 32 (see FIG. 3) of the plurality of partition plates 30. Similarly, one side portion 22 also has an opening (not shown) that communicates with each of the cooling channels 32.

[0021] As shown in Figs. 5 and 6, the housing 20 includes a pair of end plates 24, 25, bands 26, 27, and a support plate 28. In detail, as shown in Fig. 6, the support plate 28 is joined to the bottom 21 and the side portions 22, 23. The support plate 28 faces a partition plate 30-1 located at one end (negative end) of the arrangement direction D1 among the plurality of partition plates 30 in the arrangement direction D1, and is provided at a predetermined interval from the partition plate 30-1 in the arrangement direction D1. The interval between the support plate 28 and the partition plate 30-1 is, for example, as shown in Fig. 3, such that the battery cell 11 is sandwiched between the partition plate 30-1 and the support plate 28 in the arrangement direction D1. As shown in Figs. 5 and 6, one end plate 24 of the pair of end plates 24, 25 is in contact with the support plate 28 so as to be located at one end of the housing 20 in the arrangement direction D1. The other end plate 25 is in contact with the partition plate 30-6 so as to be located at the other end (positive end) of the housing 20 in the arrangement direction D1. The bands 26, 27 are arranged at a predetermined interval in the width direction D2 of the housing 20 and are joined to the bottoms of the end plates 24, 25. The bands 26, 27 may also be joined to the bottom 21 of the housing 20. Such end plates 24, 25 sandwich the storage space 29 of the housing 20 in the arrangement direction D1 to strengthen the strength of the housing 20. The bands 26, 27 strengthen the strength of the housing 20 from the bottom 21 side of the housing 20 (the lower side in the height direction D3). In addition, the end plates 24, 25 joined to the bands 26, 27 maintain a binding load sufficient to bind the multiple battery cells 11 in the storage space 29 of the housing 20.

[0022] 5 and 6, the housing 20 has an accommodation space 29 in which a plurality of battery cells 11 (see FIGS. 1 to 3) are arranged in a stacked manner and accommodated. The accommodation space 29 of the housing 20 is an internal space formed by the bottom 21, a pair of side portions 22, 23, and a support plate 28 of the housing 20. This accommodation space 29 is partitioned into individual battery cells 11 by a plurality of partition plates 30 provided in the housing 20. For example, as shown in FIG. 6, the accommodation space 29 is partitioned into accommodation chambers 29-1 to 29-6 for individual battery cells 11 by six partition plates 30-1 to 30-6.

[0023] The housing 20 having the above-mentioned configuration is formed by, for example, injection molding of resin, so that the bottom 21, the pair of side parts 22, 23, and the support plate 28 are integrated. Examples of the resin material constituting such a housing 20 include polypropylene. Alternatively, the housing 20 may be integrally molded with the plurality of partition plates 30 by, for example, injection molding of resin. In this case, examples of the resin material constituting the housing 20 include the same resin as the plurality of partition plates 30, such as olefin-based elastomers and silicone rubber. On the other hand, examples of the material constituting the end plates 24, 25 and the bands 26, 27 include, for example, resins harder than the plurality of partition plates 30, such as polypropylene, and metals such as iron or aluminum. The end plates 24, 25 may be joined to the main body of the housing 20 by a method such as welding, or may be integrally molded with the housing 20 by a method such as insert molding.

[0024] The multiple partition plates 30 have the functions of dividing the storage space 29 of the housing 20 into individual battery cells 11, cooling each of the multiple battery cells 11 stored in the storage space 29, and constraining these multiple battery cells 11 within the storage space 29.

[0025] 1 to 3, the partition plates 30 are provided in the housing 20 so as to separate the storage space 29 (see FIG. 6) of the housing 20 into each of the plurality of battery cells 11 at intervals that sandwich each of the plurality of battery cells 11 in the arrangement direction D1. The partition plates 30 are joined to or integrally molded with the bottom 21 and side portions 22, 23 of the housing 20 by resin injection molding or the like. For example, as shown in FIG. 3, the lower end of the partition plate 30-1 in the height direction D3 is integrated with the bottom 21 of the housing 20 by joining or integral molding. As shown in FIGS. 1 and 2, both ends of the partition plate 30-1 in the width direction D2 are integrated with the side portions 22, 23 of the housing 20 by joining or integral molding. The partition plates 30-1 to 30-6 are thus integrated with the housing 20, and divide the storage space 29 into storage chambers 29-1 to 29-6 (see FIG. 6) for different battery cells 11 at the above-mentioned intervals in the arrangement direction D1 of the battery cells 11.

[0026] As shown in FIG. 3, each of the partition plates 30 has a cooling flow path 32 through which a refrigerant for cooling each of the battery cells 11 flows, and an action portion 33 that acts on the battery cells 11 by utilizing the pressure of the refrigerant. The cooling flow path 32 is an internal flow path that penetrates each of the partition plates 30 in an intersecting direction intersecting with the arrangement direction D1 of the battery cells 11. In this embodiment, the cooling flow path 32 penetrates the inside of the action portion 33 in the intersecting direction. The intersecting direction in the cooling flow path 32 is the same as the width direction D2 of the housing 20 and the partition plate 30. The action portion 33 expands and contracts or expands and contracts by utilizing the pressure of the refrigerant in the cooling flow path 32, and thereby protrudes from the plate surface of the partition plate 30 in the arrangement direction D1 and comes into contact with the battery cells 11. Such an action portion 33 applies a load to a battery cell facing the arrangement direction D1 among the multiple battery cells 11 according to the pressure of the refrigerant in the cooling flow path 32, and exchanges heat between the battery cell and the refrigerant.

[0027] For example, as shown in FIG. 3, the partition plate 30-1 has the action portion 33 protruding in the arrangement direction D1 in contact with one end surface (abdominal surface portion 13b shown in FIG. 4) of the battery cell 11-1 in the arrangement direction D1. The action portion 33 applies a load to the battery cell 11-1 while absorbing the expansion or contraction deformation of the battery cell 11-1 in the arrangement direction D1 by utilizing the pressure of the refrigerant in the cooling flow path 32. As a result, the partition plate 30-1 cooperates with the support plate 28 to sandwich the battery cell 11-1 in the arrangement direction D1, and restrains the battery cell 11-1 in the accommodation space 29 (accommodation chamber 29-1 shown in FIG. 6) of the housing 20 with an appropriate load. At the same time, the action portion 33 exchanges heat between the battery cell 11-1 and the refrigerant in the cooling flow path 32. As a result, the partition plate 30-1 cools the battery cell 11-1.

[0028] The partition plate 30-2 acts on the battery cell 11-2 that contacts it from the arrangement direction D1 in the same manner as the partition plate 30-1. As shown in FIG. 3, the battery cell 11-2 is sandwiched between the two partition plates 30-1 and 30-2 in the arrangement direction D1. That is, the partition plate 30-2 cooperates with the partition plate 30-1 to sandwich the battery cell 11-2 in the arrangement direction D1, and restrains the battery cell 11-2 in the accommodation space 29 (accommodation chamber 29-2 shown in FIG. 6) of the housing 20 with an appropriate load. At the same time, the partition plate 30-2 exchanges heat between the battery cell 11-2 and the refrigerant in the cooling flow path 32 via the action portion 33, thereby cooling the battery cell 11-2. The two partition plates 30-1 and 30-2 may cooperate to cool the battery cell 11-2.

[0029] The remaining partition plates 30-3 to 30-6 act on the battery cells 11 in the same manner as the above-described partition plates 30-1 and 30-2. In this embodiment, each of the six partition plates 30-1 to 30-6 is collectively referred to as partition plate 30. In other words, partition plate 30 refers to each of the multiple partition plates provided in the housing 20 (in this embodiment, each of the partition plates 30-1 to 30-6).

[0030] The first chamber 40 is an inlet side chamber that allows the coolant to flow into each cooling flow passage 32 (see FIG. 3) of the multiple partition plates 30. As shown in FIGS. 1 and 2, the first chamber 40 has an inlet 41 for the coolant, and is provided in a side portion 22 that is one end of the width direction D2 of the housing 20. Such a first chamber 40 forms a circulation space inside, which is connected to each cooling flow passage 32, at one end of the multiple partition plates 30 in the intersecting direction. The first chamber 40 communicates the inlet 41 with each cooling flow passage 32 through the circulation space. Here, the intersecting direction of the partition plate 30 is a direction intersecting with the arrangement direction D1 of the multiple battery cells 11, and in this embodiment, is the same as the width direction D2 of the housing 20 and the partition plate 30. That is, one end of the intersecting direction means the side portion 22 that is one end of the housing 20 in the width direction D2.

[0031] The second chamber 50 is an outlet side chamber that allows the coolant to flow out from each cooling flow path 32 of the plurality of partition plates 30. As shown in Figs. 1 and 2, the second chamber 50 has an outlet port 51 for the coolant, and is provided in the side portion 23, which is the other end of the width direction D2 of the housing 20. Such a second chamber 50 forms a circulation space that communicates with each cooling flow path 32 at the other end of the plurality of partition plates 30 in the intersecting direction. The second chamber 50 communicates each cooling flow path 32 with the outlet port 51 through the circulation space. Here, since the intersecting direction is the same as the width direction D2 of the housing 20 and the partition plate 30 in this embodiment, the other end of the intersecting direction means the side portion 23, which is the other end of the width direction D2 of the housing 20.

[0032] Next, the partition plate 30 in the embodiment of the present invention will be described in detail. Fig. 7 is a schematic diagram showing one configuration example of the partition plate in the embodiment of the present invention. Fig. 7 shows the partition plate 30 as viewed from the arrangement direction D1. Fig. 8 is a schematic cross-sectional diagram showing one configuration example of the partition plate shown in Fig. 7, taken along line BB. As shown in Figs. 7 and 8, the partition plate 30 includes a plate body 31, a cooling flow path 32, and an action portion 33.

[0033] As shown in Figs. 7 and 8, the plate body 31 is a plate-like member integrally formed with a plurality of action parts 33. As shown in Figs. 7 and 8, a plurality of cooling channels 32 are provided in the plate body 31 so as to penetrate in an intersecting direction intersecting with the arrangement direction D1 of the plurality of battery cells 11. In detail, the cooling channels 32 are formed inside each of the plurality of action parts 33 integrated with the plate body 31. Since the intersecting direction is the same as the width direction D2 of the partition plate 30, each of the plurality of (e.g., eight) cooling channels 32 is an internal channel penetrating the action part 33 in the width direction D2 of the partition plate 30. From the viewpoint of applying a constant pressure of the refrigerant flowing inside the cooling channels 32 to the plate body 31 and the action parts 33 in the partition plate 30, it is preferable that the cooling channels 32 are formed so as to have a circular cross section.

[0034] The action parts 33 act on the battery cells 11 (see FIG. 3) facing the partition plate 30 in the thickness direction (arrangement direction D1) while expanding and contracting or enlarging and contracting according to the pressure of the refrigerant in the cooling flow passage 32. In detail, the action parts 33 are made of a soft resin that can be deformed according to the pressure of the refrigerant in the cooling flow passage 32. As shown in FIG. 7, a plurality of action parts 33 (eight in this embodiment) are provided on the plate body 31 so as to extend in the width direction D2 of the partition plate 30. Also, as shown in FIG. 8, each of the plurality of action parts 33 is provided so as to protrude from the plate surface (the outer surface of the plate body 31) of the partition plate 30 in the arrangement direction D1. Such action parts 33 increase and decrease the reaction force according to the increase and decrease in the pressure of the refrigerant in the cooling flow passage 32. In this embodiment, the reaction force of the action parts 33 is a force (e.g., elasticity) that pushes back an external force applied to the action parts 33. When the pressure of the refrigerant in the cooling flow path 32 is extremely small, such as when no refrigerant is present inside the cooling flow path 32, the action portion 33 has almost no reaction force to push back an external force and is easily depressed by pressure. As the pressure of the refrigerant in the cooling flow path 32 increases, the action portion 33 increases the reaction force and becomes more elastic, and as the pressure of the refrigerant in the cooling flow path 32 decreases, the action portion 33 decreases the reaction force and becomes more elastic. The action portion 33 comes into contact with the battery cell 11 facing it in the arrangement direction D1 and applies the reaction force corresponding to the pressure of the refrigerant in the cooling flow path 32 as a load to the battery cell 11 while deforming in accordance with the expansion or contraction of the battery cell 11.

[0035] Fig. 9 is a schematic diagram showing an example of a state change of the action part of the partition plate in the embodiment of the present invention. As shown in Fig. 9, the action part 33 of the partition plate 30 protrudes from the outer surface of the plate body 31 with a reaction force according to the pressure of the refrigerant 80 in the cooling flow passage 32, and is in a state of contact with the battery cell 11 facing in the arrangement direction D1 described above (state S1). In this state S1, the action part 33 applies a load equivalent to the reaction force to the battery cell 11 while pressing the battery cell 11 with the reaction force that increases with the increase in the pressure of the refrigerant 80.

[0036] Here, the battery cell 11 expands or contracts due to its charging state and the like. The contraction of the battery cell 11 is a deformation in which the expanded battery cell 11 returns to its pre-expansion state. As shown in FIG. 9, when the battery cell 11 expands, the action part 33 receives the expanded battery cell 11 with a reaction force and maintains a state of contact with the battery cell 11 by the pressure of the refrigerant 80 (state S2). In this state S2, the action part 33 absorbs the expansion of the battery cell 11 with the reaction force and applies a reaction force (load) corresponding to the pressure of the refrigerant 80 to the battery cell 11. When the battery cell 11 contracts, the action part 33 applies a reaction force to the contracted battery cell 11 and maintains a state of contact with the battery cell 11 by utilizing the pressure of the refrigerant 80. That is, the action part 33 changes from state S2 shown in FIG. 9 to state S1. In this state S1, the action portion 33 absorbs the contraction of the battery cell 11 by a reaction force, and applies a reaction force (load) corresponding to the pressure of the refrigerant 80 to the battery cell 11. As described above, the action portion 33 repeatedly changes between states S1 and S2 in accordance with the expansion or contraction of the battery cell 11.

[0037] The resin constituting the plate body 31 and the action portion 33 of the partition plate 30 may be, for example, an elastic resin such as an olefin-based elastomer or silicone rubber, or a low-elasticity resin having a lower elasticity than the elastic resin. The low-elasticity resin may be, for example, a flexible resin.

[0038] The partition plate 30 may be joined to the housing 20 by a method such as adhesion or fitting, but from the viewpoint of reducing the labor required for joining, it is preferable to join the partition plate 30 integrally with the housing 20 by insert molding, and it is particularly preferable to mold the partition plate 30 integrally with the housing 20 by injection molding of a resin. Examples of methods for integrally molding the housing 20 and the partition plates 30 include injection molding using one type of resin and two-color molding using two types of resin.

[0039] Next, the first chamber 40 and the second chamber 50 in the embodiment of the present invention will be described in detail. Fig. 10 is a perspective view showing an example of the configuration of the first chamber and the second chamber in the embodiment of the present invention. Fig. 10 shows the first chamber 40 and the second chamber 50 before being attached to the housing 20.

[0040] As shown in FIG. 10, the first chamber 40 has the inlet 41 as described above, and is formed in a concave shape with an outer frame protruding on the opposite side to the inlet 41 along the periphery. Although not particularly shown in FIG. 10, the side 22 of the housing 20 has a plurality of openings (for example, the same number as the cooling flow paths 32) that communicate with each of the cooling flow paths 32 of the plurality of partition plates 30, similar to the other side 23. The first chamber 40 is attached to the outer surface of the side 22 of the housing 20 so as to surround the plurality of openings formed in the side 22 on the inside. As a result, the first chamber 40 forms a circulation space between the side 22 of the housing 20. This circulation space is a space that communicates each of the cooling flow paths 32 of the plurality of partition plates 30 and the inlet 41. The inlet 41 extends in the thickness direction of the first chamber 40 (the width direction D2 in FIG. 10) and is provided at the opening of the first chamber 40. For example, as shown in FIG. 10, the inlet 41 is provided at a portion on the upper end side of the first chamber 40 in the height direction D3.

[0041] As shown in FIG. 10, the second chamber 50 has the outlet 51 as described above, and is formed in a concave shape with an outer frame protruding on the opposite side to the outlet 51 along the periphery. As shown in FIG. 10, the side 23 of the housing 20 has a plurality of openings 23a (for example, the same number as the cooling channels 32) that communicate with the cooling channels 32 of the plurality of partition plates 30. The second chamber 50 is attached to the outer surface of the side 23 of the housing 20 so as to surround the plurality of openings 23a formed in the side 23. As a result, the second chamber 50 forms a circulation space between the side 23 of the housing 20. This circulation space is a space that communicates the cooling channels 32 of the plurality of partition plates 30 and the outlet 51. The outlet 51 extends in the thickness direction of the second chamber 50 (width direction D2 in FIG. 10) and is provided at the opening of the second chamber 50. For example, as shown in FIG. 10, the outlet 51 is provided at a portion on the upper end side of the second chamber 50 in the height direction D3.

[0042] The first chamber 40 and the second chamber 50 are made of a resin such as polypropylene. As shown in Fig. 10, the inlet 41 of the first chamber 40 and the outlet 51 of the second chamber 50 are located at opposite poles to each other. For example, as shown in Figs. 1 and 2, the inlet 41 of the first chamber 40 is located at one end of the arrangement direction D1 of the multiple battery cells 11, and the outlet 51 of the second chamber 50 is located at the other end of the arrangement direction D1.

[0043] Next, the flow of the refrigerant in the battery pack 10 of this embodiment will be described. Fig. 11 is an explanatory diagram for explaining the flow of the refrigerant in the battery pack 10 of this embodiment. Fig. 11 shows a schematic top view of the battery pack 10. In Fig. 11, dashed arrows show a schematic flow of the refrigerant 80.

[0044] In the battery pack 10, a flow path is formed by each of the cooling flow paths 32 (see FIG. 3, etc.) of the above-mentioned plurality of (for example, six) partition plates 30-1 to 30-6, the first chamber 40, and the second chamber 50. The coolant 80 in this embodiment flows through the battery pack 10 along this flow path.

[0045] 11, the coolant 80 flows from the inlet 41 into the flow space in the first chamber 40. The coolant 80 that has flowed in is stored in the flow space in the first chamber 40, and flows from the first chamber 40 into each of the cooling flow paths 32 of the partition plates 30-1 to 30-6. The coolant 80 then cools each of the multiple battery cells 11 while flowing through each of the cooling flow paths 32 of the partition plates 30-1 to 30-6 in one direction from the first chamber 40 to the second chamber 50 (the positive direction of the width direction D2 in FIG. 11).

[0046] For example, as shown in Fig. 3, the partition plate 30-1 has a plurality of cooling flow paths 32 (eight in this embodiment) arranged in the height direction D3. The partition plate 30-1 also has a plurality of action portions 33 in contact with the abdominal surface portion of the battery cell 11-1 facing the arrangement direction D1. In such a partition plate 30-1, the coolant 80 exchanges heat with the battery cell 11-1 via the action portions 33 of the partition plate 30-1 while flowing inside each cooling flow path 32 in the one direction, thereby cooling the battery cell 11-1. In this embodiment, the coolant 80 also in the other partition plates 30-2 to 30-6 cools the battery cell 11 via the action portions 33 while flowing inside each cooling flow path 32 in the one direction, in the same way as in the case of the partition plate 30-1.

[0047] 3, the plate body of the partition plate 30-1 is in surface contact with the abdominal surface of the battery cell 11-2 that faces the arrangement direction D1. In this partition plate 30-1, the coolant 80 exchanges heat with the battery cell 11-2 via the plate body of the partition plate 30-1 while flowing inside each cooling flow passage 32 in the above-mentioned one direction, thereby cooling the battery cell 11-2. The cooling of the battery cell 11 via the plate body of the partition plate 30-1 is also the same for the partition plates 30-2 to 30-5, which have surface contact between the battery cell 11 and the plate body in the arrangement direction D1.

[0048] As described above, by circulating the refrigerant 80 along the flow path within the battery pack 10, each of the multiple battery cells 11 can be cooled from the ventral side of the battery cell 11 by heat exchange with the refrigerant 80. As a result, the cooling efficiency of the battery cells 11 can be improved. After cooling the battery cells 11, the refrigerant 80 flows out from each of the cooling flow paths 32 of the partition plates 30-1 to 30-6 into the flow space of the second chamber 50, as shown in Fig. 11. Thereafter, the refrigerant 80 is stored in the flow space within the second chamber 50, and flows out from the outlet 51 to the outside of the battery pack 10.

[0049] The coolant 80 is not particularly limited as long as it is a fluid that can flow through each cooling flow passage 32 of the partition plate 30. For example, the coolant 80 may be a liquid such as cooling water, a gas such as cold air, or a mixed fluid of these liquids and gases.

[0050] (Battery module) Next, the configuration of a battery module according to an embodiment of the present invention will be described. Fig. 12 is a schematic diagram showing one configuration example of a battery module according to an embodiment of the present invention. As shown in Fig. 12, a battery module 1 according to an embodiment of the present invention includes the above-mentioned battery pack 10, a pump 61, a pressure sensor 62, an upstream valve 63, a downstream valve 64, and a control unit 68. The battery module 1 also includes piping 70 for allowing a refrigerant 80 to flow in and out of the battery pack 10. The piping 70 is provided with a cooling device 69 for cooling the refrigerant 80.

[0051] 12, a supply pipe 71 is connected to the inlet 41 of the battery pack 10, and an outlet pipe 72 is connected to the outlet 51 of the battery pack 10. The supply pipe 71 connects the pump 61 to the inlet 41 of the battery pack 10 via an upstream valve 63. The outlet pipe 72 connects the outlet 51 of the battery pack 10 to a cooling device 69 via a downstream valve 64. A circulation pipe 73 is connected to the cooling device 69 and the pump 61, connecting them. The supply pipe 71, outlet pipe 72, and circulation pipe 73 form piping 70 that forms a circulation path for refrigerant 80 that passes from the pump 61 through the battery pack 10 and the cooling device 69 in this order and returns to the pump 61.

[0052] The pump 61 is constituted by an electric pump or the like, and is provided in the middle of the piping 70 as shown in FIG. 12. For example, the supply pipe 71 is connected to the outlet side of the pump 61, and the circulation pipe 73 is connected to the inlet side of the pump 61. The pump 61 sends out the refrigerant 80 through the piping 70 to the cooling flow passage 32 (see FIG. 3) of the battery pack 10 at a variable flow rate. In detail, the pump 61 generates a constant-direction flow (see the dashed arrow in FIG. 12) of the refrigerant 80 inside the piping 70. That is, the pump 61 sucks the refrigerant 80 through the outlet pipe 72, the circulation pipe 73, etc., and pressure-feeds the refrigerant 80 to the battery pack 10 through the supply pipe 71, etc. At this time, the pump 61 adjusts the flow rate of the refrigerant 80 based on the control by the control unit 68, and sends out the refrigerant 80 at the adjusted flow rate to the battery pack 10.

[0053] The pump 61 is driven by energy (electricity, etc.) from a power source of a moving body or device on which the battery module 1 is mounted. For example, when the battery module 1 is mounted on a vehicle, the pump 61 is driven by energy supplied from the power source of the vehicle. In this case, the pump 61 stops driving when the vehicle is stopped or the like and energy is not being supplied from the power source. As a result, the coolant 80 is no longer supplied from the pump 61 to the battery pack 10.

[0054] The pressure sensor 62 detects the pressure between the battery cells 11 (see Figs. 1 to 3) and the refrigerant 80 in the assembled battery 10. In detail, as shown in Fig. 12, the pressure sensor 62 is provided, for example, in the middle of the outflow pipe 72 (in this embodiment, in a location near the downstream side of the downstream valve 64). The pressure sensor 62 detects the pressure of the refrigerant 80 flowing out of the assembled battery 10 through the outflow pipe 72, as an example of the pressure between the battery cells 11 in the assembled battery 10 and the refrigerant 80. Here, the pressure of the refrigerant 80 increases and decreases with an increase and decrease in the flow rate of the refrigerant 80 sent to the assembled battery 10 by the pump 61, and in the assembled battery 10, the pressure of the refrigerant 80 is applied to the battery cells 11 from the refrigerant 80 in the cooling flow passage 32 via the action portion 33 (see Fig. 3) described above. Whenever the pressure sensor 62 detects the pressure of the refrigerant 80, it transmits an electric signal indicating the detected pressure to the control unit 68.

[0055] The upstream valve 63 and the downstream valve 64 are valves for maintaining the pressure of the refrigerant 80 in each cooling flow passage 32 of the battery pack 10 in a state in which the refrigerant 80 is not supplied to the battery pack 10. In detail, as shown in FIG. 12, the upstream valve 63 is provided in a middle part of the supply pipe 71 leading to the inlet 41 of the battery pack 10, for example, a part between the inlet 41 of the battery pack 10 and the pump 61. In this embodiment, the supply pipe 71 is a pipe upstream of the cooling flow passage 32 of the battery pack 10 in the flow direction of the refrigerant 80. In addition, the downstream valve 64 is provided in a middle part of the outlet pipe 72 leading to the outlet 51 of the battery pack 10, for example, near the downstream side of the outlet 51 of the battery pack 10. In this embodiment, the outlet pipe 72 is a pipe downstream of the cooling flow passage 32 of the battery pack 10 in the flow direction of the refrigerant 80.

[0056] The upstream valve 63 and the downstream valve 64 are both open when the refrigerant 80 is being circulated by the pump 61. On the other hand, when the flow of the refrigerant 80 is stopped by stopping the operation of the pump 61, the upstream valve 63 and the downstream valve 64 are both closed. As a result, the upstream valve 63 and the downstream valve 64 prevent the outflow of the refrigerant 80 from the battery pack 10, and maintain the pressure of the refrigerant 80 in each cooling flow path 32 in the battery pack 10.

[0057] The control unit 68 controls each component of the battery module 1. In detail, the control unit 68 is configured with a memory, a CPU, etc., and controls the operation of each of the pump 61, the upstream valve 63, and the downstream valve 64 described above.

[0058] For example, the control unit 68 controls the pump 61 to adjust the flow rate of the refrigerant 80 so that the pressure detected by the pressure sensor 62 falls within a range acceptable for the battery cells 11 of the battery pack 10. In this embodiment, the pressure range acceptable for the battery cells 11 of the battery pack 10 is set by upper and lower limits of the pressure between the refrigerant 80 in the cooling flow passage 32 of the battery pack 10 and the battery cells 11. The upper limit of the pressure is the maximum pressure of the refrigerant 80 that satisfies both the first and second conditions below. The first condition is that the exterior case 12 (see FIG. 4 ) and the internal electrode (not shown) of the battery cells 11 in the battery pack 10 are kept in contact with each other. The second condition is that the battery cells 11 in the battery pack 10 are not damaged. On the other hand, the lower limit of the pressure is the minimum pressure of the refrigerant 80 when the action portion 33 of the partition plate 30 in the battery pack 10 restrains the battery cells 11 by the pressure of the refrigerant 80 in the cooling flow passage 32. These upper and lower limits of the pressure of the refrigerant 80 can be derived, for example, by experiments, simulations, or the like.

[0059] Furthermore, the control unit 68 monitors the operating state of the pump 61 continuously or intermittently at predetermined intervals, and when the pump 61 is stopped, controls the upstream valve 63 and the downstream valve 64 to be closed. On the other hand, when the pump 61 is operating, the control unit 68 controls the upstream valve 63 and the downstream valve 64 to be opened.

[0060] The cooling device 69 cools the refrigerant 80 used to cool the battery cells 11 in the battery pack 10. In detail, as shown in FIG. 12, the cooling device 69 is provided in the middle of the piping 70. For example, an outlet pipe 72 is connected to the inlet side of the cooling device 69, and a circulation pipe 73 is connected to the outlet side of the cooling device 69. The cooling device 69 collects the used refrigerant 80 from the outlet 51 of the battery pack 10 through the outlet pipe 72, and cools the collected refrigerant 80. The refrigerant 80 cooled by the cooling device 69 is sucked into the pump 61 through the circulation pipe 73, and is again pressure-fed from the pump 61 to the battery pack 10 through the supply pipe 71. The cooling device 69 may be used in common with an air conditioner for air conditioning.

[0061] Next, the operation of the battery module 1 according to the embodiment of the present invention will be described. Fig. 13 is a flow diagram showing an example of the operation of the battery module according to the embodiment of the present invention. In order to ensure both the restraining function and the cooling function for the multiple battery cells 11 housed in the casing 20, the battery module 1 appropriately executes each process of steps S101 to S107 shown in Fig. 13.

[0062] 13, the battery module 1 detects the pressure between the battery cells 11 and the refrigerant 80 in the assembled battery 10 (step S101). In step S101, the pressure sensor 62 measures the pressure of the refrigerant 80 in the outflow pipe 72 leading to the outlet 51 of the assembled battery 10 as the pressure between the battery cells 11 and the refrigerant 80. In this embodiment, the pressure of the refrigerant 80 in the outflow pipe 72 is the pressure of the refrigerant 80 that is pumped from the pump 61, flows through the assembled battery 10, and then flows out of the assembled battery 10. In the assembled battery 10, the pressure of the refrigerant 80 generates a reaction force (load) that the action portion 33 of the partition plate 30 applies to the battery cells 11. The pressure sensor 62 detects the pressure of the refrigerant 80 and transmits an electric signal indicating the detected pressure to the control unit 68.

[0063] After executing step S101, the battery module 1 judges whether or not the detected pressure (hereinafter referred to as pressure P) is within the range of pressure allowed for the battery cells 11 of the battery pack 10 (step S102). In step S102, the control unit 68 receives an electrical signal from the pressure sensor 62, and acquires the pressure indicated in the received electrical signal, i.e., the pressure P of the refrigerant 80 detected by the pressure sensor 62. Next, the control unit 68 calculates a pressure P of the refrigerant 80 and an upper reference value P for the pressure P. H and the lower reference value P L Compare with.

[0064] Here, the upper reference value P H and the lower reference value P L is a reference value for determining whether the pressure P of the refrigerant 80 is within a range permitted for the battery cell 11 (hereinafter referred to as the pressure tolerance range), and is preset in the control unit 68. For example, the upper reference value PH is the lower reference value P L The upper limit of the pressure tolerance range of battery cell 11 is P max Within the range of less than (P L <P H <P max The lower reference value P L is the lower limit of the pressure tolerance range P min Above, upper reference value P H Within the range of less than (P min <P L <P H The control unit 68 determines the pressure P and the upper reference value P H and the lower reference value P L and thereby judges whether the pressure P is within the allowable pressure range of the battery cell 11.

[0065] In step S102, the pressure P of the refrigerant 80 is set to the upper reference value P H If P≧P H ), the battery module 1 reduces the flow rate of the coolant 80 supplied to the battery pack 10 (step S103). In step S103, the control unit 68 controls the pump 61 to reduce the flow rate of the coolant 80. The pump 61 reduces the flow rate of the coolant 80 based on the control by the control unit 68, and pumps the coolant 80 after the flow rate reduction to the battery pack 10 through the supply pipe 71. As a result, the coolant 80 after the flow rate reduction flows into the battery pack 10 from the inlet 41, flows through the cooling flow passage 32 of the partition plate 30, and flows out from the outlet 51 to the outlet pipe 72. That is, the flow rate of the coolant 80 in the cooling flow passage 32 is adjusted to the flow rate after the reduction by the pump 61. The pressure of the coolant 80 decreases as the flow rate of the coolant 80 decreases.

[0066] Here, the pressure P of the refrigerant 80 is the upper reference value P HIn the above cases, the battery cells 11 in the battery pack 10 are in a state of expanding in a direction pressing the action portion 33 of the partition plate 30. Therefore, the load that the action portion 33 applies to the battery cells 11 in accordance with the pressure of the refrigerant 80 in the cooling flow passage 32 increases so as to approach the upper limit allowable for the battery cells 11. However, the pressure of the refrigerant 80 in the cooling flow passage 32 decreases in step S103, thereby suppressing the increase in the load. As a result, the load is controlled to a load within the allowable range for the battery cells 11 (preferably a constant load).

[0067] On the other hand, in step S102, the pressure P of the refrigerant 80 is lower than the lower reference value P L Above, upper reference value P H If it is less than (step S102, P L <P<P H ), the battery module 1 maintains the current flow rate of the refrigerant 80 supplied to the battery pack 10 (step S104). In step S104, the control unit 68 controls the pump 61 to maintain the current flow rate of the refrigerant 80. Based on the control by the control unit 68, the pump 61 maintains the flow rate of the refrigerant 80 at the current flow rate, and pumps the refrigerant 80 at this flow rate through the supply pipe 71 to the battery pack 10. As a result, the refrigerant 80 at the above flow rate flows through the battery pack 10 and flows out to the outflow pipe 72, just like in the case of step S103 described above. That is, the flow rate and pressure of the refrigerant 80 in the cooling flow path 32 are maintained at the current levels. Here, when the pressure P of the refrigerant 80 is increased to P L <P<P H In this case, in the battery pack 10, the load that the action portion 33 applies to the battery cell 11 in accordance with the pressure of the refrigerant 80 in the cooling flow passage 32 is controlled to be within the allowable range of the battery cell 11.

[0068] In step S102, the pressure P of the refrigerant 80 is set to the lower reference value P L If P≦P L), the battery module 1 increases the flow rate of the coolant 80 supplied to the battery pack 10 (step S105). In step S105, the control unit 68 controls the pump 61 to increase the flow rate of the coolant 80. The pump 61 increases the flow rate of the coolant 80 based on the control by the control unit 68, and pumps the coolant 80 after the increased flow rate through the supply pipe 71 to the battery pack 10. As a result, the coolant 80 after the increased flow rate flows through the battery pack 10 and flows out to the outflow pipe 72, similarly to the cases of steps S103 and S104 described above. That is, the flow rate of the coolant 80 in the cooling flow passage 32 is adjusted to the flow rate after the increase by the pump 61. The pressure of the coolant 80 increases with the increase in the flow rate of the coolant 80.

[0069] Here, the pressure P of the refrigerant 80 is the lower reference value P L In the following cases, the battery cells 11 in the battery pack 10 are in a contracted state in a direction returning to their pre-expansion state. Therefore, the load that the action unit 33 applies to the battery cells 11 in accordance with the pressure of the refrigerant 80 in the cooling flow passage 32 is decreasing so as to approach the lower limit allowable for the battery cells 11. However, the pressure of the refrigerant 80 in the cooling flow passage 32 increases in step S103, thereby suppressing the decrease in the load. As a result, the load is controlled to a load (preferably a constant load) within the allowable range for the battery cells 11.

[0070] After executing step S103, step S104, or step S105 described above, the battery module 1 determines whether the pump 61 is in a stopped state (step S106). In step S106, the control unit 68 monitors the operating state of the pump 61, and determines whether the pump 61 is in an operating state or a stopped state based on the monitoring result.

[0071] If the pump 61 is operating (step S106, No), the battery module 1 returns to the above-mentioned step S101 and repeats the processes from step S101 onward. In this case, the upstream valve 63 and the downstream valve 64 are open, and the pump 61 pressure-feeds the refrigerant 80 to the battery pack 10.

[0072] On the other hand, when the pump 61 is stopped (step S106, Yes), the battery module 1 closes the upstream valve 63 and the downstream valve 64 (step S107). In step S107, the control unit 68 controls both the upstream valve 63 and the downstream valve 64 to be closed. The upstream valve 63 switches from an open state to a closed state based on the control by the control unit 68 to close the supply pipe 71. In parallel with this, the downstream valve 64 switches from an open state to a closed state based on the control by the control unit 68 to close the outflow pipe 72. Note that the control unit 68 may control the upstream valve 63 and the downstream valve 64 in order of which valve first, or may control them simultaneously. After executing step S107, the battery module 1 returns to the above-mentioned step S106 and repeats the processes from step S106 onwards.

[0073] (Measures against thermal runaway of battery cells) Next, measures against thermal runaway of the battery cells 11 of the battery module 1 according to the embodiment of the present invention will be described. The battery cells 11 housed in the assembled battery 10 of the battery module 1 may experience thermal runaway due to overcharging, deterioration over time, abnormal usage conditions, etc. In the battery module 1, the assembled battery 10 takes measures against thermal runaway of the battery cells 11.

[0074] FIG. 14 is a schematic diagram showing an example of a countermeasure against thermal runaway of a battery cell 11 that can be taken by a battery module according to an embodiment of the present invention. In the battery pack 10, when thermal runaway occurs in any one of the multiple battery cells 11 housed in the housing space 29 of the housing 20, the thermal runaway battery cell 11 is directly cooled by the refrigerant 80. For example, as shown in FIG. 14, the partition plates 30-3 and 30-4 on both sides sandwiching the thermal runaway battery cell 11 in the arrangement direction D1 are partially melted and damaged by the high heat of the battery cell 11. As a result, the plate body 31 or the action part 33 of the partition plates 30-3 and 30-4 are damaged, and the cooling flow path 32 is damaged in a state where it opens to the battery cell 11 side. The refrigerant 80 leaks from the cooling flow path 32 in this damaged state, and the leaked refrigerant 80 falls on the battery cell 11. As a result, the battery cell 11 is cooled by the heat of vaporization of the refrigerant 80, and thermal runaway is eliminated. Note that the refrigerant 80 used to prevent thermal runaway of the battery cell 11 is preferably a non-flammable liquid, such as cooling water.

[0075] Furthermore, as described above, the storage space 29 for the multiple battery cells 11 is partitioned for each individual battery cell 11 by multiple partition plates 30. Therefore, the coolant 80 used to counter thermal runaway of the battery cell 11 as described above can be contained in the storage chamber 29-4 of that battery cell 11. As a result, it is possible to prevent the coolant 80 from spreading to the remaining battery cells 11 that are not experiencing thermal runaway.

[0076] As described above, in the battery module 1 according to the embodiment of the present invention, the housing 20 has an accommodation space 29 in which a plurality of battery cells 11 are arranged in a stacked manner, and the partition plates 30 are provided in the arrangement direction D1 of the plurality of battery cells 11 so as to separate the accommodation space 29 into individual battery cells 11 at intervals that sandwich each battery cell 11. The partition plates 30 also have cooling flow paths 32 that penetrate in an intersecting direction (e.g., width direction D2) that intersects with the arrangement direction D1, and action portions 33 that face the battery cells 11 in the arrangement direction D1, and the action portions 33 apply a load to the battery cells 11 in accordance with the pressure of the refrigerant 80 flowing through the cooling flow paths 32, and perform heat exchange between the battery cells 11 and the refrigerant 80.

[0077] Therefore, the action portion 33 of the partition plate 30 can absorb the expansion or contraction of the battery cells 11 in the thickness direction (arrangement direction D1) while restraining the multiple battery cells 11 in the storage space 29 of the housing 20 with an appropriate load according to the pressure of the refrigerant 80, and can cool the multiple battery cells 11 by heat exchange with the refrigerant 80. Therefore, the partition plate 30, which is a single component, can have both the restraining function and the cooling function for the battery cells 11, and thus the arrangement space required for the first component such as a buffer plate that performs the restraining function and the arrangement space required for the second component such as a cooling plate that performs the cooling function can be integrated into the arrangement space of the partition plate 30, which is a single component. As a result, it is possible to ensure both the restraining function and the cooling function for the battery cells, and to reduce the device scale of the battery module. Furthermore, it is possible to reduce the cost of the battery module.

[0078] Furthermore, the action portion 33 of the partition plate 30 that acts on the battery cells 11 is configured to deform in response to the pressure of the refrigerant 80 in the cooling flow path 32. Therefore, the partition plate 30 having the cooling flow path 32 and the action portion 33 can be formed from a low-rigidity resin, not limited to an elastic resin. As a result, there is no need to consider the creep of the action portion 33 when absorbing the expansion or contraction of the battery cells 11, so that an inexpensive resin can be selected as the constituent material of the partition plate 30, which can promote cost reduction of the battery module 1.

[0079] In the battery module 1 according to the embodiment of the present invention, the pump 61 sends the refrigerant 80 to the cooling passage 32 of the partition plate 30 of the assembled battery 10 through the piping 70 at a variable flow rate, the pressure sensor 62 detects the pressure between the battery cells 11 of the assembled battery 10 and the refrigerant 80, and the control unit 68 controls the pump 61 to adjust the flow rate of the refrigerant 80 so that the pressure P detected by the pressure sensor 62 is within the allowable pressure range of the battery cells 11 of the assembled battery 10. Therefore, before a load applied to the battery cells 11 from the action portion 33 of the partition plate 30 according to the pressure of the refrigerant 80 in the cooling passage 32 exceeds an upper limit of the allowable range of the battery cells 11, the pressure of the refrigerant 80 can be lowered to reduce the load to within the allowable range, and before the load falls below the lower limit of the allowable range of the battery cells 11, the pressure of the refrigerant 80 can be increased to increase the load to within the allowable range. This allows a load within the allowable range to be applied to the battery cells 11 at all times, and further allows the load applied to the battery cells 11 to be controlled to a constant value within the allowable range.

[0080] In addition, in the battery module 1 according to the embodiment of the present invention, an upstream valve 63 is provided in a pipe (supply pipe 71) upstream of the cooling flow passage 32 in the assembled battery 10 in the flow direction of the refrigerant 80, and a downstream valve 64 is provided in a pipe (outlet pipe 72) downstream of the cooling flow passage 32 in the flow direction of the refrigerant 80. The control unit 68 monitors the operation state of the pump 61, and controls the upstream valve 63 and the downstream valve 64 to be closed when the pump 61 is stopped. Therefore, when the pump 61 is stopped due to, for example, the vehicle equipped with the battery module 1 being stopped, the upstream valve 63 and the downstream valve 64 are closed to suppress the outflow of the refrigerant 80 from the cooling flow passage 32. Therefore, even if the flow of the refrigerant 80 is stopped, the cooling flow passage 32 can be maintained filled with the refrigerant 80, and as a result, the application of a load to the battery cell 11 can be maintained.

[0081] In the battery module 1 according to the embodiment of the present invention, the action portion 33 is provided so as to protrude from the plate surface of the partition plate 30 in the arrangement direction D1, and the action portion 33 is configured to increase and decrease the reaction force in accordance with the increase and decrease in the pressure of the refrigerant 80 in the cooling flow path 32. Therefore, the action portion 33 of the partition plate 30 and the battery cells 11 can be efficiently brought into contact with each other in the arrangement direction D1, and as a result, it is not necessary to use a gap filler for reducing the thermal resistance between the partition plate 30 and the battery cells 11, and therefore the manufacturing cost of the battery module 1 can be reduced. Furthermore, when accommodating (assembling) a plurality of battery cells 11 in the accommodation space 29 of the housing 20, if the cooling flow path 32 of the partition plate 30 is not filled with the refrigerant 80, the reaction force of the action portion 33 can be weakened and the action portion 33 can be easily recessed, and thus the accommodation of a plurality of battery cells 11 in the accommodation space 29 can be easily performed without being hindered by the action portion 33.

[0082] Furthermore, in the battery module 1 according to the embodiment of the present invention, the cooling flow path 32 is formed inside the action portion 33 of the partition plate 30. Therefore, the pressure of the refrigerant 80 in the cooling flow path 32 can be efficiently transmitted to the action portion 33, and thus a load can be efficiently applied from the action portion 33 to the battery cells 11 in accordance with the pressure of the refrigerant 80.

[0083] Furthermore, in the battery module 1 according to the embodiment of the present invention, the cooling flow passage 32 is formed so that the cross section of the cooling flow passage 32 is circular. This allows the pressure of the refrigerant 80 in the cooling flow passage 32 to be evenly transmitted to the action portion 33, thereby allowing a load to be applied evenly to the abdominal surface portion of the battery cell 11.

[0084] In the battery module 1 according to the embodiment of the present invention, the partition plate 30 is integrally molded with the housing 20. This allows the partition plate 30 and the housing 20 to be joined seamlessly, which prevents refrigerant from leaking from the joint between the partition plate 30 and the housing 20. In addition, the partition plate 30 and the housing 20 can be easily integrated into one structure compared to a case in which the partition plate 30 and the housing 20 are joined as separate parts, and furthermore, the molding process costs can be reduced.

[0085] Furthermore, in the battery module 1 according to the embodiment of the present invention, the partition plates 30 are made of resin. This makes it possible to easily ensure insulation between the battery cells 11 and the partition plates 30, and eliminates the need for insulation processing that would be required if metal partition plates were used.

[0086] Furthermore, in the battery module 1 according to the embodiment of the present invention, the storage space 29 that stores the multiple battery cells 11 is partitioned by partition plates 30 to separate each battery cell 11. Therefore, even if the partition plates 30 are damaged and the refrigerant leaks from the cooling flow paths 32, the leakage of the refrigerant can be contained within one section of the storage space 29 (the storage chamber for one battery cell 11). As a result, damage to the battery module 1, such as contamination or short-circuiting of the battery cells 11 by the refrigerant, can be minimized.

[0087] (Variation 1) Next, a first modified example of the partition plate 30 included in the battery pack 10 in the embodiment of the present invention will be described. FIG. 15 is a schematic diagram showing one configuration example of the partition plate according to the first modified example of the present invention. FIG. 15 shows a side view of the partition plate 30A according to the first modified example as seen from the width direction D2. As shown in FIG. 15, the partition plate 30A according to the first modified example includes a plate body 31A instead of the plate body 31 of the partition plate 30 according to the above-mentioned embodiment, a cooling flow path 32A instead of the cooling flow path 32, and an action part 33A instead of the action part 33. Although not particularly shown, the battery pack according to the first modified example includes the partition plate 30A of the first modified example instead of the partition plate 30 in the above-mentioned embodiment. The battery module according to the first modified example includes the battery pack of the first modified example instead of the battery pack 10 in the above-mentioned embodiment. The other configurations are the same as those of the above-mentioned embodiment.

[0088] As shown in Fig. 15, the plate main body 31A is a plate-like member with a hollow structure having a cooling flow passage 32A therein. As shown in Fig. 15, the cooling flow passage 32A has a slit shape when viewed from the width direction D2 of the partition plate 30A, and is provided in the plate main body 31A so as to penetrate in an intersecting direction that intersects with the arrangement direction D1 of the multiple battery cells 11. In this first modification, the intersecting direction is the same as the width direction D2 of the partition plate 30A. In other words, the cooling flow passage 32A is an internal flow passage that penetrates the partition plate 30A in the width direction D2.

[0089] As shown in FIG. 15, the action portion 33A is composed of abdominal surface portions 34a, 34b on both sides in the thickness direction (arrangement direction D1) of the plate main body 31A. The action portion 33A acts on each battery cell 11 facing both sides in the arrangement direction D1 while generating a reaction force on both sides in the arrangement direction D1 according to the pressure of the refrigerant in the cooling flow path 32A. In detail, the action portion 33A increases the reaction force applied to each battery cell 11 facing both sides in the arrangement direction D1 as the pressure of the refrigerant in the cooling flow path 32A increases. In addition, the action portion 33A weakens the reaction force applied to each battery cell 11 facing both sides in the arrangement direction D1 as the pressure of the refrigerant in the cooling flow path 32A decreases. Such an action portion 33A comes into contact with each battery cell 11 facing both sides in the arrangement direction D1, absorbs the expansion or contraction of each battery cell 11 by the reaction force, and applies a load to each battery cell 11 according to the pressure of the refrigerant in the cooling flow path 32A. As a result, the acting portion 33A absorbs the expansion or contraction of each battery cell 11 facing each other on both sides in the arrangement direction D1, and restrains each battery cell 11 within the casing of the battery pack by applying the load. Also, the acting portion 33A exchanges heat between each battery cell 11 contacting each side in the arrangement direction D1 as described above and the refrigerant in the cooling flow path 32A, thereby cooling each battery cell 11.

[0090] The battery module according to the present modified example 1 includes a battery pack provided with the above-described partition plate 30A, and is otherwise configured similarly to the above-described embodiment. Therefore, in the present modified example 1, it is possible to provide a battery module that can achieve the same effects as the above-described embodiment.

[0091] (Variation 2) Next, a second modified example of the partition plate 30 included in the battery pack 10 in the embodiment of the present invention will be described. FIG. 16 is a schematic diagram showing one configuration example of the partition plate according to the second modified example of the present invention. FIG. 16 shows a side view of the partition plate 30B according to the second modified example as seen from the width direction D2. As shown in FIG. 16, the partition plate 30B according to the second modified example has an action portion 33B instead of the action portion 33 of the partition plate 30 according to the above-mentioned embodiment. Although not particularly shown, the battery pack according to the second modified example has the partition plate 30B of the second modified example instead of the partition plate 30 in the above-mentioned embodiment. The battery module according to the second modified example has the battery pack according to the second modified example instead of the battery pack 10 in the above-mentioned embodiment. The other configurations are the same as those of the above-mentioned embodiment, and the same components are given the same reference numerals.

[0092] As shown in FIG. 16, the action portion 33B is formed in a shape (for example, rectangular in a side view from the width direction D2) that protrudes on both sides of the thickness direction (arrangement direction D1) of the plate body 31 in the partition plate 30B, and a plurality of action portions 33B (eight in this modification 2) are provided on the plate body 31. These action portions 33B are integrated with the plate body 31 by a method such as resin injection molding. Although not shown in FIG. 16, the action portion 33B extends in the width direction D2 of the partition plate 30B, similar to the action portion 33 (see FIG. 7) of the above-mentioned embodiment. Also, as shown in FIG. 16, a cooling flow path 32 having a circular cross section is provided inside each of the action portions 33B. In this modification 2, the cooling flow path 32 is an internal flow path that is located at the center of the thickness direction of the plate body 31 and penetrates the action portion 33 in a cross direction (for example, the width direction D2) that crosses the above-mentioned arrangement direction D1.

[0093] The above-mentioned action portion 33B acts on each battery cell 11 facing on both sides in the arrangement direction D1 while generating a reaction force on both sides in the arrangement direction D1 according to the pressure of the refrigerant in the cooling flow path 32. In detail, the action portion 33B increases the reaction force applied to each battery cell 11 facing on both sides in the arrangement direction D1 as the pressure of the refrigerant in the cooling flow path 32 increases. Moreover, the action portion 33B decreases the reaction force applied to each battery cell 11 facing on both sides in the arrangement direction D1 as the pressure of the refrigerant in the cooling flow path 32 decreases. Such an action portion 33B comes into contact with each battery cell 11 facing on both sides in the arrangement direction D1, absorbs the expansion or contraction of each battery cell 11 by the reaction force, and applies a load to each battery cell 11 according to the pressure of the refrigerant in the cooling flow path 32. As a result, the acting portion 33B absorbs the expansion or contraction of each battery cell 11 facing each other on both sides in the arrangement direction D1, and restrains each battery cell 11 within the casing of the battery pack by applying the load. Also, the acting portion 33B exchanges heat between each battery cell 11 contacting each side in the arrangement direction D1 as described above and the refrigerant in the cooling flow path 32, thereby cooling each battery cell 11.

[0094] The battery module according to the present modified example 2 includes a battery pack provided with the above-mentioned partition plate 30B, and is otherwise configured similarly to the above-mentioned embodiment. Therefore, in the present modified example 2, it is possible to provide a battery module that can achieve the same effects as the above-mentioned embodiment and can exert a restraining function and a cooling function on each battery cell 11 from both sides in the arrangement direction D1.

[0095] (Variation 3) Next, a third modification of the partition plate 30 included in the battery pack 10 in the embodiment of the present invention will be described. FIG. 17 is a schematic diagram showing one configuration example of the partition plate according to the third modification of the present invention. FIG. 17 shows a side view of the partition plate 30C according to the third modification from the width direction D2. As shown in FIG. 17, the partition plate 30C according to the third modification includes an action portion 33C instead of the action portion 33 of the partition plate 30 according to the above-mentioned embodiment. Although not particularly shown, the battery pack according to the third modification includes the partition plate 30C of the third modification instead of the partition plate 30 in the above-mentioned embodiment. The battery module according to the third modification includes the battery pack according to the third modification instead of the battery pack 10 in the above-mentioned embodiment. The other configurations are the same as those of the above-mentioned embodiment, and the same components are given the same reference numerals.

[0096] As shown in Fig. 17, the action portion 33C is formed in a shape (e.g., rectangular in side view from the width direction D2) that protrudes in the thickness direction (arrangement direction D1) of the plate main body 31 in the partition plate 30C, and a plurality of action portions 33C (eight in this modification 3) are provided on the plate main body 31. The configuration of the action portion 33C in this modification 3 is similar to the action portion 33 of the partition plate 30 in the above-described embodiment, except for the rectangular shape in side view from the width direction D2. For example, as shown in Fig. 17, a cooling flow path 32 having a circular cross section is provided inside each of the plurality of action portions 33C.

[0097] The battery module according to the present modified example 3 includes a battery pack provided with the above-described partition plate 30C, and is otherwise configured similarly to the above-described embodiment. Therefore, in the present modified example 3, it is possible to provide a battery module that can achieve the same effects as the above-described embodiment.

[0098] (Variation 4) Next, a fourth modification of the partition plate 30 included in the battery pack 10 in the embodiment of the present invention will be described. FIG. 18 is a schematic diagram showing one configuration example of the partition plate according to the fourth modification of the present invention. FIG. 18 shows a side view of the partition plate 30D according to the fourth modification as seen from the width direction D2. As shown in FIG. 18, the partition plate 30D according to the fourth modification includes a plate body 31D instead of the plate body 31 of the partition plate 30 according to the above-mentioned embodiment, and includes an action portion 33D instead of the action portion 33. Although not particularly shown, the battery pack according to the fourth modification includes the partition plate 30D of the fourth modification instead of the partition plate 30 in the above-mentioned embodiment. The battery module according to the fourth modification includes the battery pack according to the fourth modification instead of the battery pack 10 in the above-mentioned embodiment. The other configurations are the same as those of the above-mentioned embodiment, and the same components are given the same reference numerals.

[0099] 18, the plate body 31D is a plate-like member in which a plurality of action portions 33D are integrally formed, and is formed to be thinner than the plate body 31 of the partition plate 30 in the above-described embodiment. The configuration of the plate body 31D is similar to that of the plate body 31 in the above-described embodiment, except that it is formed to be thinner as described above.

[0100] As shown in Fig. 18, the action portion 33D is formed so as to protrude in the thickness direction (arrangement direction D1) of the plate main body 31 in the partition plate 30D, and a plurality of action portions (eight in this modification 4) are provided on the plate main body 31D. Moreover, the action portion 33D is formed to be thinner than the action portion 33 of the partition plate 30 in the above-mentioned embodiment. The configuration of the action portion 33D is similar to that of the action portion 33 in the above-mentioned embodiment, except that it is formed to be thinner as described above. For example, as shown in Fig. 18, a cooling flow passage 32 having a circular cross section is provided inside each of the plurality of action portions 33D.

[0101] The battery module according to the present modification 4 includes a battery pack provided with the above-mentioned partition plate 30D, and is otherwise configured similarly to the above-mentioned embodiment. Therefore, in the present modification 4, it is possible to provide a battery module that can enjoy the same effects as the above-mentioned embodiment, and can further promote miniaturization of the device and cost reduction by thinning the partition plate 30D.

[0102] In the above-mentioned embodiment and modified examples 1 to 4, six battery cells are accommodated in the housing storage space, but the present invention is not limited to this. For example, the number of battery cells accommodated in the storage space is not limited to the above-mentioned six, but may be two or more. Furthermore, the number of partition plates that divide the storage space is not limited to the above-mentioned six, but may be any number necessary to divide the storage space according to the accommodated battery cells, and may be, for example, two or more.

[0103] In addition, in the above-mentioned embodiment and modified examples 1 to 4, the number of cooling channels and action parts provided on the partition plate is 8 or 1, but the present invention is not limited to this. For example, the number of cooling channels and action parts provided on the partition plate may be 1, or 2 or more. Furthermore, the numbers of these may be the same or different.

[0104] In addition, in the above-mentioned embodiment and modified examples 1 to 4, the cooling flow passages extending in the width direction of the partition plate are exemplified, but the present invention is not limited to this. For example, the cooling flow passages provided in the partition plate may be flow passages that extend in a direction across the battery cells from the first chamber on the entry side to the second chamber on the exit side, and the extension direction of the cooling flow passages may be inclined with respect to the width direction.

[0105] In the above-described embodiment and modifications 1 to 4, the cooling passage is provided inside the action part of the partition plate, but the present invention is not limited to this. For example, the cooling passage may be provided inside the plate body of the partition plate.

[0106] In the above-mentioned embodiment and modified examples 1 to 4, the refrigerant inlet is provided at the upper end in the height direction of the first chamber, and the refrigerant outlet is provided at the upper end in the height direction of the second chamber, but the present invention is not limited to this. For example, these inlet and outlet may be provided at desired locations (lower end or center, etc.) in the first chamber and the second chamber, respectively. Furthermore, the number of inlet and outlet provided in each of the first chamber and the second chamber is not limited to one as described above, and may be more than one.

[0107] In the above-described embodiment and modifications 1 to 4, a pressure sensor is provided in the supply pipe leading to the inlet of the battery pack, and this pressure sensor detects the pressure of the refrigerant in this supply pipe as the pressure between the battery cells in the battery pack and the refrigerant, but the present invention is not limited to this. For example, a pressure sensor may be provided between a battery cell located at one end of the arrangement direction of the multiple battery cells contained in the battery pack and an end plate, and the pressure applied to the battery cell from the acting portion of the partition plate may be detected as the pressure between the battery cells in the battery pack and the refrigerant.

[0108] In the above-described embodiment and modifications 1 to 4, the piping that forms a refrigerant circulation path is illustrated as the piping that is connected to the battery pack, but the present invention is not limited to this. The piping that is connected to the inlet of the battery pack and the piping that is connected to the outlet of the battery pack do not need to be in communication with each other, that is, they do not need to be piping that forms a refrigerant circulation path.

[0109] In the above-mentioned embodiment and modified examples 1 to 4, the flow rate of the coolant flowing through the battery pack is controlled by driving and controlling the pump based on the pressure of the coolant detected by the pressure sensor, but the present invention is not limited to this. For example, the flow rate of the coolant flowing through the battery pack may be controlled based on the voltage of the battery cells in the battery pack based on the phenomenon that the higher the voltage of the battery cell (i.e., the higher the charge amount), the greater the expansion of the battery cell, and the lower the voltage of the battery cell (i.e., the lower the charge amount), the smaller the expansion of the battery cell. In detail, a voltmeter may be provided in the battery pack instead of the pressure sensor, and the voltmeter may measure the voltage of the battery cells in the battery pack. When the measured voltage is higher than or equal to an upper reference value, the control unit may control the pump to reduce the flow rate of the coolant, and when the measured voltage is lower than or equal to a lower reference value, the control unit may control the pump to increase the flow rate of the coolant.

[0110] Furthermore, the present invention is not limited to the above-mentioned embodiment and modifications 1 to 4, and the present invention also includes configurations in which the above-mentioned components are appropriately combined. In addition, other embodiments, examples, operation techniques, etc. made by those skilled in the art based on the above-mentioned embodiment and modifications 1 to 4 are all included in the scope of the present invention. [Explanation of symbols]

[0111] 1 Battery module 10 Battery pack 11, 11-1, 11-2 Battery cell 12 Outer case 13a, 13b Ventral part 14a, 14b side part 15 Bottom 16 Lid 17, 18 Electrode terminal 20. Cabinet 21 Bottom 22, 23 Side 23a opening 24, 25 End plate 26, 27 Band 28 Support plate 29 Containment Space Containment Rooms 29-1~29-6 30, 30-1~30-6, 30A, 30B, 30C, 30D Partition plate 31, 31A, 31D board body 32, 32A Cooling Channel 33, 33A, 33B, 33C, 33D Working part 34a, 34b Ventral part 40 First Chamber 41 Inlet 50 Second Chamber 51 Outlet 61 Pump 62 Pressure Sensor 63 Upstream valve 64 Downstream valve 65 Thermistor 66 Voltmeter 67 Output section 68 Control Unit 69 Cooling device 70 Piping 71 Supply pipe 72 Outflow pipe 73 Circulation tube 80 Refrigerant D1 Array direction D2 width direction D3 Height direction

Claims

1. a housing having a storage space in which a plurality of battery cells are arranged in a stacked manner; a plurality of partition plates provided in the housing at intervals that sandwich each of the plurality of battery cells in an arrangement direction of the plurality of battery cells so as to separate the storage space into each of the plurality of battery cells; Equipped with Each of the plurality of partition plates is The plate body and a cooling flow path that passes through the cooling medium in a direction intersecting the arrangement direction and through which a coolant flows; an operating portion that applies a load to battery cells among the plurality of battery cells that face each other in the arrangement direction in accordance with a pressure of the refrigerant in the cooling flow path and exchanges heat between the battery cells and the refrigerant, The plate body is a plate-shaped member in which a plurality of the action portions are integrally formed, The cooling flow path is formed inside each of the plurality of action parts integrated with the plate body, A battery module comprising:

2. a pump that delivers the coolant to the cooling passage through a pipe at a variable flow rate; a pressure sensor that detects a pressure between the battery cell and the refrigerant; a control unit that causes the pump to adjust the flow rate of the coolant so that the pressure detected by the pressure sensor is within an allowable range for the battery cell; The battery module according to claim 1 , further comprising:

3. an upstream valve provided in a pipe upstream of the cooling flow path in a flow direction of the refrigerant; a downstream valve provided in a pipe downstream of the cooling flow path in a flow direction of the refrigerant; Equipped with The control unit monitors an operating state of the pump, and when the pump is stopped, controls the upstream valve and the downstream valve to be closed. The battery module according to claim 2 .

4. the action portion is provided so as to protrude from each plate surface of the plurality of partition plates in the arrangement direction, and the amount of protrusion is increased or decreased in accordance with an increase or decrease in pressure of the refrigerant in the cooling flow path.

4. The battery module according to claim 1, wherein the first and second electrodes are electrically connected to each other.

5. The cooling flow path is formed inside the action part. The battery module according to claim 4 .

6. The cooling flow passage is formed so that a cross section thereof is circular.

6. The battery module according to claim 1, wherein the first and second electrodes are electrically connected to each other.

7. The partition plates are integrally formed with the housing.

7. The battery module according to claim 1, wherein the first and second electrodes are electrically connected to each other.

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