Fixing structure between battery module and cooling plate and manufacturing method thereof

Abstract

To provide a fixing structure between a battery module and a cooling plate and a manufacturing method thereof, which are capable of realizing secure fixing and excellent heat conduction between the battery module and the cooling plate.SOLUTION: A fixing structure of a battery module and a cooling plate is a fixing structure of a battery module holding a plurality of battery cells and a cooling plate disposed in contact with a portion thereof. In the fixing structure of the battery module and the cooling plate, the cooling plate has a plurality of recesses on the surface of the battery module side. In the plurality of recesses, adhesive material is provided in some of the recesses, and heat-conductive material is provided in the remaining recesses.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fixing structure for a battery module and a cooling plate and a manufacturing method thereof, and more particularly to a fixing structure for a battery module and a cooling plate that can achieve reliable fixing and excellent heat conduction between the battery module and the cooling plate and a manufacturing method thereof. [Background technology]

[0002] Conventionally, a battery module that can reduce the number of fastening parts such as bolts used has been proposed in order to increase the energy density of a battery pack (see Patent Document 1). In this battery module, a thermally conductive lower plate, typically a cooling plate, and multiple battery cells are fixed together with a resin layer having a predetermined adhesive strength and thermal conductivity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6681911 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are only a limited number of adhesives that can realize the resin layer described in Patent Document 1, and such adhesives have a problem of being expensive because they have specialized uses. Therefore, the present inventors attempted to fix the battery module to the cooling plate using a general, inexpensive adhesive for fixing and a thermally conductive material for heat conduction, but discovered a new technical problem in that the adhesive and the thermally conductive material were mixed in the fixing area between the cooling plate and the battery module, making it impossible to guarantee performance.

[0005] The present invention has been made based on these new technical challenges, and aims to provide a fixing structure between a battery module and a cooling plate, and a manufacturing method thereof, which can achieve reliable fixation and excellent heat conduction between the battery module and the cooling plate. [Means for solving the problem]

[0006] As a result of extensive research into achieving the above-mentioned objective, the inventors discovered that the above-mentioned objective could be achieved by providing an adhesive material in some of the multiple recesses provided in the cooling plate and providing a thermally conductive material in the remaining recesses, and thus completed the present invention.

[0007] That is, the fixing structure of the present invention between a battery module and a cooling plate is a fixing structure between a battery module holding a plurality of battery cells and a cooling plate arranged in contact with a portion of the battery module. In this fixing structure, the cooling plate has a plurality of recesses on its surface facing the battery module. Furthermore, among these recesses, some recesses are provided with an adhesive material, and the remaining recesses are provided with a thermally conductive material.

[0008] Furthermore, a manufacturing method of a fixing structure between a battery module and a cooling plate according to the present invention is a method for manufacturing the fixing structure between a battery module and a cooling plate according to the present invention, and includes the following steps (A) to (C). Step (A) is a step of providing a pre-solidified / hardened adhesive material in some of the recesses of the cooling plate so that the adhesive material protrudes beyond the upper open ends of the recesses, and providing a pre-solidified / hardened thermally conductive material in the remaining recesses so that the adhesive material protrudes beyond the upper open ends of the recesses. Step (B) is performed after step (A) and is a step of crushing the pre-solidified / hardened adhesive material and the pre-solidified / hardened thermally conductive material with the battery module, and arranging the battery module in a fixed position relative to the cooling plate. Step (C) is performed after step (B) and is a step of solidifying or hardening the pre-solidified / hardened adhesive material and the pre-solidified / hardened thermally conductive material. [Effects of the Invention]

[0009] According to the present invention, adhesive is provided in some of the multiple recesses provided in the cooling plate, and thermally conductive material is provided in the remaining recesses, thereby providing a fixing structure between a battery module and a cooling plate and a manufacturing method thereof that can achieve secure fixation and excellent thermal conduction between the battery module and the cooling plate. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1(A) is a front view showing a schematic diagram of one embodiment of the fixing structure of the present invention between a battery module and a cooling plate, and FIG. 1(B) is a plan view showing a schematic diagram of the fixing structure of FIG. 1(A) with the left side portion of the battery module cut away. [Figure 2] FIG. 2(A) is a front view schematically showing another embodiment of the fixing structure between a battery module and a cooling plate of the present invention, and FIG. 2(B) is a plan view schematically showing the state in which the left side portion of the battery module in the fixing structure of FIG. 2(A) is cut away. [Figure 3] FIG. 3(A) is a front view schematically showing yet another embodiment of the fixing structure between a battery module and a cooling plate of the present invention, and FIG. 3(B) is a plan view schematically showing the state in which the left side portion of the battery module in the fixing structure of FIG. 3(A) is cut away. [Figure 4] FIG. 4(A) is a front view schematically showing yet another embodiment of the fixing structure between a battery module and a cooling plate of the present invention, and FIG. 4(B) is a plan view schematically showing the fixing structure of FIG. 4(A). [Figure 5] FIG. 5(A) is a front view schematically showing yet another embodiment of the fixing structure between a battery module and a cooling plate of the present invention, and FIG. 5(B) is a plan view schematically showing the fixing structure of FIG. 5(A). [Figure 6] 1A to 1C are explanatory views schematically illustrating an embodiment of a method for manufacturing a fixing structure between a battery module and a cooling plate according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a fixing structure for a battery module and a cooling plate and a manufacturing method thereof according to the present invention will be described in detail with reference to the drawings. Note that the dimensional proportions in the drawings cited below are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0012] [First embodiment] As shown in Fig. 1, the fixing structure 1 for a battery module and a cooling plate of this embodiment is a fixing structure for a battery module 10 that holds a plurality of battery cells 11, 11, and a cooling plate 20 that is arranged in contact with a portion of the battery module 10. Note that in Fig. 1, the battery cells 11 are indicated by dashed lines. Strictly speaking, an adhesive or the like may be interposed between the battery module 10 and the cooling plate 20. Furthermore, in the illustrated example, the battery module 10 holds five battery cells 11, but the number of battery cells 11 can be changed as appropriate depending on the capacity, voltage, and other factors required for the battery module 10. Hereinafter, the "fixing structure between the battery module and the cooling plate" may be simply referred to as the "fixing structure," the "battery module" may be simply referred to as the "module," and the "battery cell" may be simply referred to as the "cell."

[0013] In the fixing structure of this embodiment, the cooling plate 20 installed on the bottom side of the module 10 has a plurality of recesses 20C,...,20C on a surface 20A on the module 10 side. The plurality of recesses 20C,...,20C have a rectangular cross section, are formed as grooves extending in a direction perpendicular to the paper surface of FIG. 1(A), are formed in parallel straight lines, and are open to an end surface 20B of the cooling plate 20.

[0014] In the fixing structure of the present invention, among the plurality of recesses 20C, adhesive material 30 is provided in some of the recesses 20C, and thermally conductive material 40 is provided in the remaining recesses 20C. However, in this embodiment, the adhesive material 30 and the thermally conductive material 40 are provided alternately for each recess 20C. Furthermore, each of the plurality of cells 11, 11, has a rectangular plate shape with its longer sides extending in the left-right direction of FIG. 1 . In a plan view, the cells 11 are arranged perpendicular to the adhesive material 30 and the thermally conductive material 40, and are in direct contact with the adhesive material 30 and the thermally conductive material 40. In the illustrated example, the cooling plate 20 has 13 recesses 20C, but the number of recesses 20C can be changed as appropriate depending on the performance of the adhesive material 30 and the thermally conductive material 40, the number of cells 11 held in the module 10, and other factors.

[0015] Next, the advantages of this embodiment will be described. According to the fixing structure 1 of this embodiment, the adhesive material 30 and the thermally conductive material 40 are alternately arranged in each of the multiple recesses 20C, 20C, provided in the cooling plate 20. This makes it possible to suppress or prevent the adhesive material 30 and the thermally conductive material 40 from mixing together, even in a structure in which the adhesive material 30 and the thermally conductive material 40 tend to mix together. As a result, the intended effects of the adhesive material 30 and the thermally conductive material 40 are achieved, and reliable fixation and excellent thermal conduction between the battery module 10 and the cooling plate 20 can be achieved.

[0016] Furthermore, because the multiple recesses 20C are formed in a groove-like shape, when the battery module is placed in a fixed position, air that inhibits secure fixation and excellent heat conduction between the adhesive 30 or thermally conductive material 40 and the cooling plate 20, as well as excess adhesive 30 or thermally conductive material 40, can easily escape in the extension direction of the groove-like recesses 20C. As will be described in detail later, when the battery module is placed in a fixed position, the adhesive 30 and thermally conductive material 40 exist as unsolidified or hardened adhesive or thermally conductive material, which is easily movable and deformable. This allows for more secure fixation and even better heat conduction between the battery module 10 and the cooling plate 20.

[0017] Furthermore, since the multiple recesses 20C are formed as linear grooves parallel to one another, excess adhesive 30 and thermally conductive material 40 are suppressed or prevented from spilling out from the upper open ends 20E of the recesses 20C, thereby achieving more reliable fixation between the battery module 10 and the cooling plate 20 and even better thermal conduction.

[0018] Furthermore, since the plurality of recesses 20C,..., 20C formed in a groove shape are open to the end surface 20B of the cooling plate 20, excess adhesive material 30 and thermally conductive material 40 can easily escape from the recesses 20C on the end surface 20B side of the cooling plate 20. This allows for more reliable fixation between the battery module 10 and the cooling plate 20 and even better thermal conduction.

[0019] Furthermore, since the plurality of recesses 20C, . . . , 20C formed in a groove shape have a rectangular cross section, the ridges 20D between the recesses 20C formed in a groove shape further suppress or prevent the adhesive material 30 and the thermally conductive material 40 from being mixed together. This makes it possible to achieve more reliable fixation between the battery module 10 and the cooling plate 20 and even better thermal conduction.

[0020] Furthermore, each of the multiple battery cells 11, ..., 11 is arranged perpendicular to the adhesive 30 and the thermally conductive material 40 in a planar view and is in direct contact with the adhesive 30 and the thermally conductive material 40, which makes it easier to achieve the effects of secure fixation and excellent thermal conduction between the battery cells 11 and the cooling plate 20 in the battery module 10.

[0021] [Second embodiment] As shown in Fig. 2, the fixing structure 2 of this embodiment has the same configuration as the fixing structure 1 of the first embodiment, except that each of the multiple cells 11, . . . , 11 has a rectangular plate shape with its longer sides extending in the vertical direction of Fig. 2 and is arranged parallel to the adhesive material 30 and the thermally conductive material 40 in a plan view. Note that in Fig. 2, the battery cells 11 are indicated by dashed dotted lines. According to the fixing structure 2 of this embodiment, even if the arrangement of the cells, adhesive material, and thermally conductive material is different from that of the first embodiment, such as the arrangement of the cells, adhesive material, and thermally conductive material described above, the same effect as the fixing structure 1 of the first embodiment can be achieved.

[0022] [Third embodiment] As shown in Fig. 3, the fixing structure 3 of this embodiment has the same configuration as the fixing structure 1 of the first embodiment, except that the fixing structure 3 has a structure in which the multiple recesses 20C, ..., 20C formed in a groove shape have a V-shaped cross section. Note that in Fig. 3, the battery cells 11 are indicated by dashed dotted lines. In the fixing structure 3 of this embodiment, since the recesses 20C have a V-shaped cross section, in addition to the advantages of the fixing structure 1 of the first embodiment, there are fewer corners where air tends to remain, which makes it easier for air to escape, and the module 10 and the cooling plate 20 can be effectively fixed with small amounts of adhesive 30 and thermally conductive material 40.

[0023] [Fourth embodiment] As shown in FIG. 4, the fixing structure 4 of this embodiment includes a plurality of modules 10, 10 each having a rectangular plate shape with its longer sides extending in the left-right direction of FIG. 4, and has the same configuration as the fixing structures 1 and 2 of the first or second embodiment except that, in a plan view, the fixing structure 4 has a structure in which the proportion of thermally conductive material 40 is greater than the proportion of adhesive material 30 in a temperature-rise-prone portion 10A located in the center of the module 10. Note that cells are not shown in FIGS. 4 and 5. The fixing structure 4 of this embodiment can achieve the same effects as the fixing structures 1 and 2 of the first or second embodiment even when the temperature-rise-prone portion 10A is located in the center of the module 10.

[0024] [Fifth embodiment] As shown in Fig. 5, the fixing structure 5 of this embodiment includes a plurality of modules 10, 10 in the shape of a rectangular plate with the longer sides extending in the left-right direction of Fig. 5, and has the same configuration as the fixing structures 1 and 2 of the first or second embodiment, except that in a plan view, the fixing structure 5 has a structure in which the proportion of thermally conductive material 40 in the temperature-rise-prone portions 10A located at the ends of the modules 10 is greater than the proportion of adhesive material 30. The fixing structure 5 of this embodiment can achieve the same effects as the fixing structures 1 and 2 of the first or second embodiment, even when the temperature-rise-prone portions 10A are located at the ends of the modules 10 described above.

[0025] [Sixth embodiment] As shown in FIG. 6, the method for manufacturing the fixing structure of the battery module and the cooling plate of this embodiment is a method for manufacturing the fixing structure of the above-mentioned embodiment, and includes the following steps (A) to (C).

[0026] In the manufacturing method of the fixing structure of the present invention, adhesive material 30 is provided in some of the multiple recesses 20C, ..., 20C of the cooling plate 20, and thermally conductive material 40 is provided in the remaining recesses 20C, but in this embodiment, in step (A), as shown in Figure 6 (A), adhesive material 31 and thermally conductive material 41 before solidification / hardening are provided alternately in each recess 20C, with the adhesive material 31 and thermally conductive material 41 protruding beyond the upper open end 20E of the recess 20C.

[0027] Next, in step (B), as shown in Fig. 6(B), the module 10 is pressed as indicated by arrow Z to crush the pre-solidification / hardening adhesive material 31 and the pre-solidification / hardening thermal conductive material 41, and the module 10 is placed at a fixed position relative to the cooling plate 20. Here, the "fixed position" may be, for example, a position where the module 10 and the cooling plate 20 come into contact with each other.

[0028] Thereafter, in step (C), the pre-solidification / hardening adhesive 31 and the pre-solidification / hardening thermally conductive material 41 are solidified or hardened by a solidification or hardening method appropriate for the type of adhesive and thermally conductive material. As a result, as shown in Fig. 6(C), the pre-solidification / hardening adhesive 31 becomes the adhesive material 30, and the pre-solidification / hardening thermally conductive material 41 becomes the thermally conductive material 40, and the fixing member of the above-described embodiment can be obtained with a good yield.

[0029] Furthermore, in step (A), it is preferable that the volumes of the pre-solidified / hardening adhesive material 31 and the pre-solidified / hardening thermally conductive material 41 are equal to or less than the volumes of the recesses 20C in which they are provided. This further suppresses or prevents the pre-solidified / hardening adhesive material 31 and the pre-solidified / hardening thermally conductive material 41 from spilling out of the recesses 20, and the fixing structure of the above-described embodiment can be obtained with a higher yield.

[0030] Furthermore, when the plurality of groove-shaped recesses 20C,..., 20C are open to the end surface 20B of the cooling plate 20, it is preferable to make the volumes of the pre-solidification / hardening adhesive 31 and the pre-solidification / hardening thermally conductive material 41 larger than the volumes of the recesses 20C in which they are provided in step (A). This allows air and excess adhesive 30 and thermally conductive material 40 to escape from the end surface 20B side of the recesses 20C of the cooling plate 20, and the fixing structure of the above-described embodiment can be obtained with a higher yield.

[0031] Here, the specifications, materials, etc. of the components in the above-described embodiment will be described in detail.

[0032] (battery module) The module 10 may include a frame- or box-shaped fixing member for holding the plurality of cells 11. Preferably, the module 10 does not include a member constituting the fixing member on the cooling plate 20 side. Examples of the cells 11 held by the module 10 include conventionally known secondary batteries such as lithium-ion secondary batteries. Examples of the cells 11 include cells whose exterior is formed of conventionally known rectangular metal cans or aluminum laminates. Examples of the module 10 include a stack of multiple cells 11, . . . , 11. The module 10 is preferably one in which the cells 11 are stacked in the thickness direction of the cells 11. For example, the module 10 may have the stacking arrangement direction of the cells 11 aligned with the length direction of the module 10, or the length direction of the cells 11 aligned with the length direction of the module 10. Here, a cell whose length direction is aligned with the length direction of the module 10 and whose length is five times or more the width of the cell 11 is sometimes referred to as a long cell.

[0033] (Cooling plate) The cooling plate 20 is not particularly limited as long as it can dissipate heat generated in the module 20. For example, the cooling plate is preferably formed from a metal material such as aluminum, copper, or stainless steel, and among these, it is more preferable to form it from a metal material such as aluminum or copper, which has excellent thermal conductivity. Furthermore, a suitable example of the cooling plate 20 is one that allows a gas (e.g., air) or liquid (e.g., water) to flow as a coolant on the side opposite to the surface on which the multiple recesses are formed.

[0034] (Adhesive material, adhesive material before solidification and curing) Examples of the adhesive 30 include resin-based adhesives such as urea resin-based adhesives, melamine resin-based adhesives, phenol resin-based adhesives, resorcinol resin-based adhesives, epoxy-based adhesives, polyester-based adhesives, polyurethane-based adhesives, polyamide-based adhesives, polyimide-based adhesives, vinyl acetate resin-based adhesives, vinyl chloride resin-based adhesives, polyvinyl alcohol-based adhesives, acrylic resin-based adhesives, polyolefin-based adhesives, and silicone resin-based adhesives; rubber-based adhesives such as chloroprene rubber-based adhesives, nitrile rubber-based adhesives, SBR-based adhesives, natural rubber-based adhesives, recycled rubber-based adhesives, butyl rubber-based adhesives, block rubber-based adhesives, polysulfide-based adhesives, and silicone-based adhesives; and other adhesives such as polyisobutylene-based adhesives, polyvinyl ether-based adhesives, chlorinated rubber-based adhesives, cellulose-based adhesives, and asphalt-based adhesives. Among them, preferred examples include thermosetting resin adhesives such as urea resin adhesives, phenol resin adhesives, melamine resin adhesives, epoxy resin adhesives, etc. Furthermore, examples of the pre-solidification / hardening adhesive 31 include those that become the adhesive 30 upon hardening or hardening.

[0035] (Thermal conductive material, pre-solidified / pre-hardened thermal conductive material) The thermally conductive material 40 is not particularly limited as long as it adheres closely to the module 10 and the cooling plate 20 and exhibits higher thermal conductivity than air. A suitable example of the thermally conductive material 40 is a thermally conductive adhesive that has higher thermal conductivity and lower adhesiveness than the adhesive 30. Specific examples of the thermally conductive material include resins such as urea resin, melamine resin, phenolic resin, resorcinol resin, epoxy resin, polyester resin, polyurethane resin, polyamide resin, polyimide resin, vinyl acetate resin, vinyl chloride resin, polyvinyl alcohol resin, acrylic resin, polyolefin resin, and silicone resin, and rubbers such as chloroprene rubber, nitrile rubber, SBR, natural rubber, recycled rubber, butyl rubber, block rubber, polysulfide, and silicone. Among these, acrylic resin, polyurethane resin, silicone resin, epoxy resin, and polyolefin resin are preferred, epoxy resin and polyolefin resin are more preferred, and polyolefin resin is even more preferred. Furthermore, suitable examples include those in which a thermally conductive inorganic filler is added to improve thermal conductivity. Examples of such inorganic fillers include aluminum oxide, magnesium oxide, zinc oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, silicon carbide, boron carbide, titanium carbide, and diamond. Furthermore, examples of the thermally conductive adhesive include those obtained by adding the above-mentioned inorganic fillers having thermal conductivity to the above-mentioned adhesives. Furthermore, examples of the pre-solidification / hardening thermal conductive material 41 include those that solidify or harden to become the above-mentioned thermal conductive material 40.

[0036] Although the present invention has been described above with reference to some embodiments, the present invention is not limited to these, and various modifications are possible within the scope of the gist of the present invention.

[0037] Although the recesses in the above-described embodiment are described as being formed in a groove shape, the present invention is not limited to this as long as the adhesive material and the thermally conductive material can be prevented from mixing. For example, the recesses may be formed in a grid shape.

[0038] Furthermore, although the multiple recesses in the above-described embodiment are described as being open on the end face of the cooling plate, the present invention is not limited to this as long as the mixing of the adhesive and the thermally conductive material can be suppressed or prevented. For example, the multiple recesses may be surrounded by a ridge formed on the edge of the cooling plate.

[0039] In addition, although the adhesive material and the thermally conductive material in the above-described embodiment are alternately arranged, the present invention is not limited to this as long as the mixing of the adhesive material and the thermally conductive material can be suppressed or prevented. For example, the thermally conductive material may be arranged so that it is more abundant in the area where the temperature is likely to rise.

[0040] Furthermore, in the above-described embodiment, the multiple recesses have been described as having rectangular or V-shaped cross-sectional shapes, from the viewpoint of ease of processing and formation, but they may also have, for example, an arc-shaped cross-sectional shape.

[0041] In addition, although the above-described embodiment has been described with reference to an example in which each of the plurality of battery cells is in direct contact with the adhesive material and the thermally conductive material, the present invention is not limited to this as long as the mixing of the adhesive material and the thermally conductive material can be suppressed or prevented. For example, an insulating layer or a thermally conductive layer may be further provided between the battery cell and the adhesive material or the thermally conductive material. [Explanation of symbols]

[0042] 1,2,3,4,5 Fixed structure 10 Battery Module 10A Parts prone to temperature rise 11 battery cells 20 Cooling Plate 20A surface 20B end face 20C recess 20D Convex part 20E Upper open end 30 Adhesive 31 Adhesive before solidification and curing 40 Thermal Conductive Materials 41 Pre-solidified thermal conductive material

Claims

1. A fixing structure of a battery module that holds a plurality of battery cells and a cooling plate that is disposed in contact with a part of the battery module, the cooling plate has a plurality of recesses on a surface facing the battery module, Among the plurality of recesses, some recesses are provided with an adhesive material, and the remaining recesses are provided with a thermally conductive material. A fixing structure for a battery module and a cooling plate, characterized by:

2. The fixing structure for the battery module and the cooling plate according to claim 1 , wherein the plurality of recesses are formed in the shape of grooves.

3. 3. The structure for fixing a battery module and a cooling plate according to claim 2, wherein the plurality of recesses are formed as linear grooves parallel to each other.

4. 4. The structure for fixing a battery module and a cooling plate according to claim 2, wherein the plurality of recesses are open to an end surface of the cooling plate.

5. 5. The fixing structure for a battery module and a cooling plate according to claim 2, wherein the adhesive material and the thermally conductive material are alternately arranged in each of the recesses.

6. 6. The structure for fixing a battery module and a cooling plate according to claim 2, wherein the plurality of recesses have a rectangular cross section.

7. 6. The structure for fixing a battery module and a cooling plate according to claim 2, wherein the plurality of recesses have a V-shaped cross section.

8. 8. The fixing structure for a battery module and a cooling plate according to claim 1, wherein each of the plurality of battery cells is in direct contact with the adhesive material and the thermally conductive material.

9. The fixing structure of a battery module and a cooling plate according to any one of claims 1 to 8, characterized in that, in a plan view, the proportion of the thermally conductive material in the temperature-easily rising portion of the battery module is greater than the proportion of the adhesive.

10. A method for manufacturing the fixing structure of the battery module and the cooling plate according to any one of claims 1 to 9, comprising the following steps (A) to (C): Step (A): providing an adhesive material before solidification / hardening in some of the recesses among the plurality of recesses of the cooling plate in a state in which the adhesive material protrudes beyond the upper open ends of the recesses, and providing a thermally conductive material before solidification / hardening in the remaining recesses in a state in which the thermally conductive material protrudes beyond the upper open ends of the recesses; Step (B): A step performed after the step (A), in which the pre-solidified adhesive material and the pre-solidified thermal conductive material are crushed in the battery module, and the battery module is disposed in a fixed position relative to the cooling plate; Step (C): A step that is carried out after step (B) and solidifies or hardens the pre-solidification / hardening adhesive material and the pre-solidification / hardening thermal conductive material. A method for manufacturing a fixing structure between a battery module and a cooling plate.

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