Battery module

Abstract

To provide a battery module in which a larger number of battery cells can be stored in a case.SOLUTION: A battery module 11 includes: a battery cell formed by sealing an electrode body with a laminate film; and a case 13 for storing a battery cell group 25 in which a plurality of battery cells are arranged. A lubricant 50 is provided between the battery cell group 25 and the case 13.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a battery module in which an electrode assembly is housed in a case. Further, by surrounding the outside of the electrode assembly with a heat-shrinkable protective layer, a structure is provided that suppresses the thermal expansion of the electrode assembly.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, from the viewpoint of improving the volume efficiency of the battery, it is preferable to house the battery cells in the case of the battery module without any gaps. However, when there is no margin in the volume of the case with respect to the volume of the battery cell group in which a plurality of battery cells are arranged, it becomes difficult to insert the battery cell group into the case.

[0005] In consideration of the above facts, an object of the present invention is to obtain a battery module capable of housing more battery cells in a case.

Means for Solving the Problems

[0006] The battery module according to claim 1 includes a battery cell formed by sealing an electrode body with a laminate film, and a case capable of housing a battery cell group in which a plurality of the battery cells are arranged, and a lubricant is provided between the battery cell group and the case.

[0007] In the battery module according to claim 1, the battery cell is formed by sealing an electrode body with a laminate film, and the case is capable of accommodating a battery cell group in which a plurality of battery cells are arranged. Further, a lubricant is provided between the battery cell group and the case. Therefore, the frictional resistance when inserting the battery cell group into the case can be reduced by the lubricant.

[0008] The battery module according to claim 2 is, in claim 1, wherein the lubricant is formed to contain a material that volatilizes in a specific environment.

[0009] In the battery module according to claim 2, after inserting the battery cell group into the case and placing it in a specific environment, the lubricant volatilizes, suppressing the battery cell group from coming out of the case.

[0010] The battery module according to claim 3 is, in claim 1, wherein the lubricant is formed to contain a material that increases the withdrawal resistance of the battery cell from the case in a specific environment.

[0011] In the battery module according to claim 3, after inserting the battery cell group into the case and placing it in a specific environment, the withdrawal resistance of the battery cell from the case increases, suppressing the battery cell group from coming out of the case.

[0012] The battery module according to claim 4 is, in claim 3, wherein the lubricant is solid and is formed to contain a material whose coefficient of friction increases in a specific environment.

[0013] In the battery module according to claim 4, the coefficient of friction of the lubricant increases in a specific environment, suppressing the battery cell group from coming out of the case.

[0014] The battery module according to claim 5 is, in claim 3, wherein the lubricant is formed to contain a material whose volume increases in a specific environment.

[0015] In the battery module according to claim 5, the increase in the volume of the lubricant in a specific environment can suppress the battery cell group from coming out of the case.

[0016] The battery module according to claim 6 is, in any one of claims 2 to 5, wherein the specific environment is a reduced pressure environment in which the pressure is reduced from the atmospheric pressure.

[0017] In the battery module according to claim 6, it is possible to suppress the battery cell group from coming out of the case only by reducing the pressure after housing the battery cell group in the case.

[0018] The battery module according to claim 7 is, in any one of claims 2 to 5, wherein the specific environment is a high temperature environment in which the temperature is equal to or higher than a predetermined temperature.

[0019] In the battery module according to claim 7, it is possible to suppress the battery cell group from coming out of the case only by placing the battery cell group in a high temperature environment after housing it in the case.

[0020] The battery module according to claim 8 is, in claim 1, wherein the battery cell group is configured to include a buffer plate provided outside the array direction of the outermost battery cell among the plurality of arranged battery cells, and a lubricant is provided between the buffer plate and the case.

[0021] In the battery module according to claim 8, since both ends of the battery cell group serve as buffer plates, the surface pressure acting on the battery cells can be adjusted.

Effect of the Invention

[0022] As described above, according to the battery module according to the present invention, more battery cells can be housed in the case.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

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Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0024] <First Embodiment> The battery module 11 according to the first embodiment will be described with reference to the drawings.

[0025] (Overall Configuration of Vehicle 100) FIG. 1 is a schematic plan view showing a main part of a vehicle 100 to which a battery pack 10 according to the present embodiment is applied. As shown in FIG. 1, the vehicle 100 is a battery electric vehicle (BEV) in which the battery pack 10 is mounted under the floor. In addition, the arrows UP, FR, and LH in each figure indicate the upper side in the vehicle vertical direction, the front side in the vehicle longitudinal direction, and the left side in the vehicle width direction, respectively. When using the directions of front, rear, left, right, up, and down for description, unless otherwise specified, the front and rear in the vehicle longitudinal direction, the left and right in the vehicle width direction, and the up and down in the vehicle vertical direction are shown.

[0026] As an example, in the vehicle 100 of this embodiment, a DC / DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 are arranged on the front side of the vehicle with respect to the battery pack 10. Also, on the rear side of the vehicle with respect to the battery pack 10, a motor 108, a gearbox 110, an inverter 112, and a charger 114 are arranged.

[0027] The direct current output from the battery pack 10 is supplied to the electric compressor 104, the PTC heater 106, the inverter 112, etc. after the voltage is adjusted by the DC / DC converter 102. Also, by supplying power to the motor 108 via the inverter 112, the rear wheels rotate to make the vehicle 100 travel.

[0028] A charging port 116 is provided on the right side at the rear of the vehicle 100. By connecting a charging plug of an external charging facility (not shown) to the charging port 116, power can be stored in the battery pack 10 via the in-vehicle charger 114.

[0029] Note that the arrangement and structure of each component constituting the vehicle 100 are not limited to the above-described configuration. For example, it may be applied to a hybrid vehicle (HV: Hybrid Vehicle) or a plug-in hybrid electric vehicle (PHEV: Plug-in Hybrid Electric Vehicle) equipped with an engine. Also, in this embodiment, the vehicle is a rear-wheel drive vehicle with the motor 108 mounted at the rear of the vehicle, but it is not limited to this. It may be a front-wheel drive vehicle with the motor 108 mounted at the front of the vehicle, or a pair of motors 108 may be mounted at the front and rear of the vehicle. Furthermore, it may be a vehicle equipped with in-wheel motors on each wheel.

[0030] Here, the battery pack 10 is configured to include a plurality of battery modules 11. In this embodiment, as an example, 10 battery modules 11 are provided. Specifically, 5 battery modules 11 are arranged in the vehicle front-rear direction on the right side of the vehicle 100, and 5 battery modules 11 are arranged in the vehicle front-rear direction on the left side of the vehicle 100. Also, each of the battery modules 11 is electrically connected.

[0031] FIG. 2 is a schematic perspective view of the battery module 11. As shown in FIG. 2, the battery module 11 is formed in a substantially rectangular parallelepiped shape with the vehicle width direction as the longitudinal direction. Also, the case 13 of the battery module 11 is formed of an aluminum alloy. For example, the case 13 of the battery module 11 is formed by joining aluminum die-castings to both ends of an extruded material of an aluminum alloy by laser welding or the like.

[0032] A pair of voltage terminals 12 and a connector 14 are provided at both ends in the vehicle width direction of the battery module 11, respectively. A flexible printed circuit board 21 described later is connected to the connector 14. Also, bus bars (not shown) are welded to both ends in the vehicle width direction of the battery module 11.

[0033] The length MW in the vehicle width direction of the battery module 11 is, for example, 350 mm to 600 mm, the length ML in the vehicle front-rear direction is, for example, 150 mm to 250 mm, and the height MH in the vehicle vertical direction is, for example, 80 mm to 110 mm.

[0034] FIG. 3 is a plan view of the battery module 11 with the upper lid removed. As shown in FIG. 3, a plurality of battery cells 20 are accommodated in the battery module 11 in an arranged state. In this embodiment, as an example, 24 battery cells 20 are arranged in the vehicle front-rear direction and adhered to each other.

[0035] On top of the battery cell 20, a flexible printed circuit (FPC) 21 is disposed. The flexible printed circuit 21 is formed in a strip shape with the vehicle width direction as the longitudinal direction, and thermistors 23 are provided at both ends of the flexible printed circuit 21, respectively. The thermistor 23 is not adhered to the battery cell 20 and is configured to be pressed toward the battery cell 20 side by the upper lid of the battery module 11.

[0036] Also, inside the battery module 11, one or more buffer plates (not shown) are accommodated. For example, the buffer plate is a thin plate-like member that can be elastically deformed and is disposed between adjacent battery cells 20 with the arrangement direction of the battery cells 20 as the thickness direction. In this embodiment, as an example, buffer materials are disposed at both longitudinal ends and the central portion in the longitudinal direction of the battery module 11, respectively.

[0037] FIG. 4 is a schematic view of the battery cell 20 accommodated in the battery module 11 as viewed from the thickness direction. As shown in FIG. 4, the battery cell 20 is formed in a substantially rectangular plate shape, and a long electrode body 19 is accommodated therein. The electrode body 19 is configured by laminating a positive electrode, a negative electrode, and a separator, and is sealed by a laminate film 22.

[0038] In this embodiment, as an example, the accommodation portion of the electrode body 19 is formed by folding and bonding an embossed sheet-like laminate film 22. Note that both a single cup emboss structure with one embossing and a double cup emboss structure with two embossings can be adopted, but in this embodiment, a single cup emboss structure with a drawing depth of about 8 mm to 10 mm is used.

[0039] The upper ends at both longitudinal ends of the battery cell 20 are bent, and the corners form the outer shape. Also, the upper end portion of the battery cell 20 is bent, and a fixing tape 24 is wound along the longitudinal direction on the upper end portion of the battery cell 20.

[0040] Here, terminals (tabs) 26 are provided at both longitudinal ends of the battery cell 20. In this embodiment, as an example, the terminal 26 is provided at a position offset downward from the center in the vertical direction of the battery cell 20. The terminal 26 is joined to a bus bar (not shown) by laser welding or the like.

[0041] The length CW1 of the battery cell 20 in the vehicle width direction is, for example, 530 mm to 600 mm, the length CW2 of the region in which the electrode body 19 is accommodated is, for example, 500 mm to 520 mm, and the height CH of the battery cell 20 is, for example, 80 mm to 110 mm. Therefore, the battery cell 20 is formed in a long shape, and the directions of the lengths CW1 and CW2 are the longitudinal directions.

[0042] Also, the thickness of the battery cell 20 is 7.0 mm to 9.0 mm, and the height TH of the terminal 26 is 40 mm to 50 mm.

[0043] FIG. 5 is a schematic cross-sectional view showing a state in which the battery cell group 25 is inserted into the case 13 of the battery module 11 in this embodiment. For convenience of explanation, a plurality of battery cells 20 in which 24 battery cells 20 are arranged in the vehicle front-rear direction and adhered to each other are depicted as one battery cell group 25.

[0044] As shown in FIG. 5, a lubricant 50 is provided between the battery cell group 25 and the case 13. In this embodiment, as an example, the lubricant 50 is configured to include a lubricating oil that volatilizes in a reduced-pressure environment. In other words, the lubricant 50 is formed to include a material that increases the extraction resistance of the battery cell group 25 with respect to the case 13 in a specific environment. Here, the “lubricant” referred to herein is a concept that widely includes members capable of reducing the friction between the battery cell group 25 and the case 13 and is not limited to liquids.

[0045] Also, in this embodiment, as an example, buffer plates are provided at both ends in the arrangement direction of the battery cell group 25, and the lubricant 50 is interposed between the buffer plates and the case 13.

[0046] For example, when manufacturing the battery module 11, first, the lubricant 50 is supplied into the case 13. Then, with the lubricant 50 applied to the inner wall of the case 13, the battery cell group 25 is inserted into the case 13. At this time, the lubricant 50 is interposed between the buffer plate of the battery cell group 25 and the case 13, thereby reducing the frictional force during insertion.

[0047] After the battery cell group 25 is inserted into the case 13 and before the case 13 is covered, by reducing the pressure, the lubricant 50 volatilizes, and the battery cell group 25 and the case 13 are fixed by the frictional force.

[0048] (Function) Next, the function of the battery module 11 according to the present embodiment will be described.

[0049] In the battery module 11 according to the present embodiment, the battery cell 20 is formed by sealing the electrode body 19 with the laminate film 22, and the case 13 can accommodate the battery cell group 25 in which a plurality of battery cells 20 are arranged. Further, a lubricant 50 is provided between the battery cell group 25 and the case 13. Therefore, the frictional resistance when inserting the battery cell group 25 into the case 13 can be reduced by the lubricant 50.

[0050] Also, in the present embodiment, after the battery cell group 25 is inserted into the case 13, by placing it in a specific environment, the lubricant 50 can be volatilized to suppress the battery cell group 25 from coming out of the case 13. In particular, by using the lubricant 50 that volatilizes in a reduced-pressure environment as in the present embodiment, it is possible to suppress the battery cell group 25 from coming out of the case 13 only by reducing the pressure after the battery cell group 25 is accommodated in the case 13.

[0051] That is, after the battery cell group 25 is inserted into the case 13, by placing it in a reduced-pressure environment, the resistance of the battery cell 20 to come out of the case 13 increases, and the battery cell group 25 can be suppressed from coming out of the case 13. As a result, more battery cells 20 can be accommodated in the case 13.

[0052] Further, in the present embodiment, since both ends of the battery cell group 25 serve as buffer plates, the surface pressure acting on the battery cells 20 can be adjusted.

[0053] <Second Embodiment> Next, the battery module 60 according to the second embodiment will be described with reference to FIG. 6. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0054] FIG. 6 is a plan sectional view schematically showing a state in which the battery cell group 25 is inserted into the case 13. As shown in FIG. 6, in the present embodiment, a plate-shaped lubricant 52 is provided between the battery cell group 25 and the case 13.

[0055] The lubricant 52 in the present embodiment is different from that in the first embodiment in that it is solid. The lubricant 52 is configured in a plate shape, and has a friction coefficient smaller than the friction coefficients of both the battery cell group 25 and the case 13 on both surfaces. That is, the surface of the lubricant 52 has a smaller surface roughness than the battery cell group 25 and the case 13.

[0056] Further, the lubricant 52 in the present embodiment is formed to contain a material that does not volatilize in a reduced-pressure environment and increases the volume in a high-temperature environment to increase the extraction resistance of the battery cell group 25. In other words, the lubricant 52 is formed to contain a material whose friction coefficient increases in a specific environment. Further, the lubricant 52 is preferably formed of a material that is hardly thermally shrunk even when cooled to room temperature.

[0057] (Operation) Next, the operation of the battery module 60 according to the present embodiment will be described.

[0058] In the battery module 60 according to the present embodiment, by simply placing the battery cell group 25 in the case 13 and then in a high-temperature environment, the volume of the lubricant 52 increases, and the battery cell group 25 can be prevented from coming out of the case 13. Other operations are the same as those in the first embodiment.

[0059] <Third Embodiment> Next, the battery module 70 according to the second embodiment will be described with reference to FIG. 7. For the components similar to those of the first embodiment, the same reference numerals will be used and the description thereof will be omitted as appropriate.

[0060] FIG. 7 is a schematic cross-sectional view showing a state where the battery cell group 25 is inserted into the case 13. As shown in FIG. 7, in the present embodiment, a lubricant 50 similar to that of the first embodiment is provided between the battery cell group 25 and the case 13.

[0061] In addition, locking claws 13A project from the inner wall of the opening portion of the case 13 in directions facing each other. Here, the locking claw 13A has an inclined surface inclined so that the protruding amount increases as it goes from the opening of the case 13 toward the back side. Therefore, when the battery cell group 25 is inserted into the case 13, the battery cell group 25 is inserted along the inclined surface of the locking claw 13A, and thus the resistance acting on the battery cell group 25 from the locking claw 13A is not large. On the other hand, when the battery cell group 25 moves in the direction of coming out from the inserted state, a relatively large frictional force acts on the battery cell group 25 from the locking claw 13A, thereby increasing the resistance to coming out of the battery cell group 25.

[0062] (Operation) Next, the operation of the battery module 60 according to the present embodiment will be described.

[0063] In the battery module 70 according to the present embodiment, the lubricant 50 can enhance the insertability of the battery cell group 25 while suppressing the battery cell group 25 from coming out of the case 13.

[0064] In addition, if a structure is adopted in which the gap between the case 13 and the battery cell group 25 is sealed by the locking claw 13A, it is possible to suppress the lubricant 50 from leaking out of the case 13. That is, it is not necessary to volatilize the lubricant 50. Other operations are the same as those of the first embodiment.

[0065] Although the battery modules 11, 60, and 70 according to the embodiments have been described above, the present invention is not limited thereto, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention. For example, as the lubricant, a material whose friction coefficient increases due to an increase in viscosity under a specific environment may be used. Further, when the lubricant is a solid such as a buffer plate, a material whose friction coefficient increases due to an increase in surface roughness under a specific environment may be used.

[0066] Further, as the specific environment, a lubricant containing a material that increases the extraction resistance of the battery cell on the condition that a predetermined time or more has elapsed may be used.

[0067] Regarding the above embodiment, the following appendices are disclosed.

[0068] (Appendix 1) A battery cell formed by sealing an electrode body with a laminate film, A case capable of accommodating a battery cell group in which a plurality of the battery cells are arranged, and a lubricant is provided between the battery cell group and the case. Battery module. (Appendix 2) The battery module according to Appendix 1, wherein the lubricant is formed to contain a material that volatilizes under a specific environment. (Appendix 3) The battery module according to Appendix 1, wherein the lubricant is formed to contain a material that increases the extraction resistance of the battery cell with respect to the case under a specific environment. (Appendix 4) The battery module according to Appendix 3, wherein the lubricant is a solid and is formed to contain a material whose friction coefficient increases under a specific environment. (Appendix 5) The battery module according to Appendix 3, wherein the lubricant is formed to contain a material whose volume increases under a specific environment. (Appendix 6) The battery module according to any one of Appendices 2 to 5, wherein the specific environment is a reduced-pressure environment in which the pressure is lower than the atmospheric pressure. (Appendix 7) The specific environment is a high-temperature environment where the temperature is equal to or higher than a predetermined temperature, and the battery module according to any one of Appendices 2 to 5. (Appendix 8) The battery cell group is configured to include a buffer plate provided outside the arrangement direction of the outermost battery cell among the plurality of arranged battery cells, and a lubricant is provided between the buffer plate and the case, and the battery module according to any one of Appendices 1 to 7.

Explanation of Reference Numerals

[0069] 11 Battery module 13 Case 19 Electrode body 20 Battery cell 22 Laminate film 25 Battery cell group 50 Lubricant 52 Lubricant 60 Battery module 70 Battery module

Claims

1. a battery cell formed by sealing the electrode body with a laminate film; a case capable of accommodating a battery cell group in which a plurality of the battery cells are arranged; having A lubricant is provided between the battery cell group and the case. Battery module.

2. The battery module according to claim 1 , wherein the lubricant is formed by containing a material that volatilizes under a specific environment.

3. The battery module according to claim 1 , wherein the lubricant is formed by including a material that increases resistance to the battery cells being pulled out of the case under a specific environment.

4. The battery module according to claim 3 , wherein the lubricant is a solid and is formed by including a material whose coefficient of friction increases under a specific environment.

5. The battery module according to claim 3 , wherein the lubricant is formed by containing a material that increases in volume under a specific environment.

6. The battery module according to any one of claims 2 to 5, wherein the specific environment is a reduced pressure environment where the pressure is reduced below atmospheric pressure.

7. The battery module according to any one of claims 2 to 5, wherein the specific environment is a high-temperature environment having a predetermined temperature or higher.

8. the battery cell group includes a buffer plate provided on an outer side in an arrangement direction of an outermost battery cell among the plurality of arranged battery cells, A lubricant is provided between the buffer plate and the case. The battery module according to claim 1 .

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