Battery module and battery pack

Abstract

To efficiently release heat generated from a battery cell.SOLUTION: A battery module 100 includes a battery cell 102, a module housing 110 that accommodates the battery cell 102, and a thermally conductive adhesive 116a that exists at least partially between the battery cell 102 and the module housing 110. Unevenness exists on a surface of the module housing 110 where the thermally conductive adhesive 116a exists and a surface of the module housing 110 opposite to the surface where the thermally conductive adhesive 116a exists.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] In recent years, various battery packs have been developed. A battery pack includes a battery module and a pack housing that houses the battery module. A battery module includes battery cells and a module housing that houses the battery cells.

[0003] Patent Document 1 describes a battery module. The battery module includes a battery cell assembly and a housing that houses the battery cell assembly. The housing has a lower plate located below the battery cell assembly. A protrusion is provided on the upper surface of the lower plate.

[0004] Patent Document 2 describes a battery module. The battery module includes a plurality of secondary batteries and a cooling plate located below the plurality of secondary batteries. A protrusion is provided on the upper surface of the cooling plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-21640 [Patent Document 2] Special Publication No. 2019-508846 Summary of the Invention [Problem to be solved by the invention]

[0006] Heat may be generated from a battery cell. When heat is generated from a battery cell, it may be required to efficiently dissipate the heat generated from the battery cell.

[0007] One example of an object of the present invention is to efficiently dissipate heat generated from a battery cell. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0008] One aspect of the present invention is as follows. 1. A battery cell; a housing that houses the battery cell; a thermally conductive material at least partially positioned between the battery cell and the housing; Equipped with The battery module has irregularities on a surface of the housing on which the thermally conductive material is located and on a surface of the housing opposite to the side on which the thermally conductive material is located. 2. A plurality of the battery cells are arranged in a predetermined direction, 1. The battery module according to claim 1, wherein the irregularities extend at least partially non-perpendicular to the predetermined direction. 3. The battery module according to 1., wherein a plurality of the projections and recesses are at least partially scattered. 4. A battery module according to any one of 1. to 3.; a thermal conductor at least partially overlapping the battery module; Equipped with The battery pack, wherein the irregularities of the housing are at least partially located between the thermally conductive material and the thermal conductor. 5. The battery pack according to claim 4, further comprising a filler positioned at least partially between the housing and the thermal conductor. [Effects of the Invention]

[0009] According to the above aspect of the present invention, heat generated from the battery cells can be efficiently released. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a battery pack according to an embodiment. [Figure 2]FIG. 2 is a plan view of the battery pack according to the embodiment with the upper case removed. [Figure 3] FIG. 2 is a plan view of the battery module according to the embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view of FIG. 3 taken along the line AA. [Figure 5] FIG. 4 is a schematic cross-sectional view of FIG. 3 taken along the line B-B. [Figure 6] FIG. 10 is a schematic plan view of a sixth plate according to the embodiment. [Figure 7] FIG. 7 is a diagram showing a modification of FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments and modifications of the present invention will be described with reference to the drawings. In all the drawings, similar components are designated by similar reference numerals, and descriptions thereof will be omitted as appropriate.

[0012] Fig. 1 is a perspective view of a battery pack 10 according to an embodiment. Fig. 2 is a plan view of the battery pack 10 according to an embodiment with an upper case 220 removed.

[0013] In the embodiment, the battery pack 10 is mounted on an automobile. Specifically, the battery pack 10 is mounted between the front and rear wheels of the automobile. Unless otherwise specified, the following description will be given assuming that the battery pack 10 is mounted on an automobile. However, the battery pack 10 can also be used for purposes other than automobiles.

[0014] For the purpose of explanation, the X, Y, and Z directions are shown in each figure. The X direction indicates the front-to-rear direction of the battery pack 10. The Y direction is perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery pack 10. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-to-down direction of the battery pack 10. The arrow pointing to the X direction, the arrow pointing to the Y direction, and the arrow pointing to the Z direction indicate the front, left, and up directions of the battery pack 10, respectively. In FIG. 2, the white circle with a black dot indicating the Z direction indicates that the arrow pointing to the Z direction extends from the back of the page to the front. However, the relationship between the X direction, the Y direction, and the Z direction and the front-to-rear direction, left-to-right direction, and up-to-down direction of the battery pack 10 is not limited to this example.

[0015] In the embodiment, the front-rear direction, left-right direction, and up-down direction of the battery pack 10 are determined by the vehicle in which the battery pack 10 is mounted. The X direction, Y direction, and Z direction respectively indicate the front-rear direction, left-right direction, and up-down direction of the vehicle. The arrow pointing to the X direction, the arrow pointing to the Y direction, and the arrow pointing to the Z direction respectively indicate the front, left, and up directions of the vehicle. However, the relationship between the front-rear direction, left-right direction, and up-down direction of the battery pack 10 and the front-rear direction, left-right, and up-down directions of the vehicle is not limited to this example.

[0016] Hereinafter, as needed, the side indicated by the arrow indicating the X direction will be referred to as the +X side, and the side opposite the side indicated by the arrow indicating the X direction will be referred to as the -X side. Hereinafter, as needed, the side indicated by the arrow indicating the Y direction will be referred to as the +Y side, and the side opposite the side indicated by the arrow indicating the Y direction will be referred to as the -Y side. Hereinafter, as needed, the side indicated by the arrow indicating the Z direction will be referred to as the +Z side, and the side opposite the side indicated by the arrow indicating the Z direction will be referred to as the -Z side.

[0017] The battery pack 10 includes four battery modules 100 and a pack housing 200. The four battery modules 100 include a pair of battery modules 100 on the left side aligned in the X direction and a pair of battery modules 100 on the right side aligned in the X direction. The pack housing 200 includes a lower case 210 and an upper case 220. The lower case 210 may generally be referred to as, for example, a tray or a main body. The lower case 210 includes a lower plate 212 and a side frame 214. The upper case 220 may generally be referred to as, for example, a cover or a lid. As will be described later, each battery module 100 includes a plurality of battery cells 102.

[0018] A pair of terminals 215 is provided in front of the side frame 214. The pair of terminals 215 is aligned in the Y direction. The front end of each terminal 215 protrudes forward from the front surface of the side frame 214. In the electrical path, the four battery modules 100 are connected in series between the pair of terminals 215.

[0019] The lower case 210 and the upper case 220 are attached to each other via a sealant 230. The lower case 210, the upper case 220, and the sealant 230 form an accommodating space 250. Four battery modules 100 are accommodated in the accommodating space 250.

[0020] The lower plate 212 defines the bottom of the storage space 250. The side frames 214 define the sides of the storage space 250. Specifically, when viewed from the Z direction, the side frames 214 are provided along the outermost periphery of the lower plate 212. The upper case 220 defines the top of the storage space 250.

[0021] The sealing material 230 is an elastic material such as rubber. When viewed from the Z direction, the sealing material 230 is provided around the entire periphery of the side frame 214. As a result, when viewed from the Z direction, the sealing material 230 surrounds the storage space 250. Therefore, the sealing material 230 can seal the storage space 250 from the space outside the pack housing 200.

[0022] The number and arrangement of the battery modules 100 are not limited to the examples according to the embodiments. For example, the number of battery modules 100 may be only two, only three, or five or more.

[0023] FIG. 3 is a plan view of a battery module 100 according to an embodiment. FIG. 4 is a schematic cross-sectional view taken along line AA in FIG. 3. FIG. 5 is a schematic cross-sectional view taken along line BB in FIG. 3. FIG. 6 is a schematic plan view of a sixth plate 116 according to an embodiment. In FIG. 4, a white circle with a black dot indicating the X direction indicates that an arrow indicating the X direction extends from the back of the page to the front. In FIG. 5, a white circle with a black dot indicating the Y direction indicates that an arrow indicating the Y direction extends from the back of the page to the front.

[0024] As shown in FIG. 4, the battery module 100 includes a cell stack 102G and a module housing 110.

[0025] The cell stack 102G includes a plurality of battery cells 102 and a plurality of compression pads 104. In the example shown in Fig. 4, the plurality of battery cells 102 and the plurality of compression pads 104 are arranged alternately in the Y direction. For example, in the cell stack 102G, a plurality of battery cell groups, each including a plurality of battery cells 102 connected in parallel, are connected in series. Alternatively, a plurality of single battery cells 102 may be connected in series.

[0026] The module housing 110 accommodates the cell stack 102G. As shown in FIGS. 3 to 5, the module housing 110 includes a first plate 111, a second plate 112, a third plate 113, a fourth plate 114, a fifth plate 115, and a sixth plate 116. The first plate 111 covers a portion of the cell stack 102G on the +X side. The second plate 112 covers a portion of the cell stack 102G on the -X side. The third plate 113 covers a portion of the cell stack 102G on the +Y side. The fourth plate 114 covers a portion of the cell stack 102G on the -Y side. The fifth plate 115 covers a portion of the cell stack 102G on the +Z side, with a structural adhesive 115a at least partially positioned between the cell stack 102G and the fifth plate 115. The cell stack 102G and the fifth plate 115 are bonded to each other via the structural adhesive 115a. The sixth plate 116 covers the -Z side portion of the cell stack 102G, with the thermally conductive adhesive 116a at least partially positioned between the cell stack 102G and the sixth plate 116. The cell stack 102G and the sixth plate 116 are bonded to each other via the thermally conductive adhesive 116a. The cell stack 102G and the sixth plate 116 are thermally coupled to each other via the thermally conductive adhesive 116a. Therefore, heat generated from the battery cells 102 can be dissipated to the sixth plate 116 via the thermally conductive adhesive 116a. The thermal conductivity of the thermally conductive adhesive 116a is higher than that of the structural adhesive 115a. Therefore, heat generated from the battery cells 102 can be more easily conducted toward the thermally conductive adhesive 116a than toward the structural adhesive 115a.

[0027] As shown in FIG. 4, the lower case 210 includes a support frame 216. When viewed from the Z direction, the support frame 216 is an enclosure that surrounds at least a portion of the cell stack 102G. The support frame 216 is provided on the +Z side of the +Z side surface of the lower plate 212. Hereinafter, as needed, the portion of the support frame 216 located on the +Y side of the cell stack 102G as shown in FIG. 4 will be referred to as a first support portion 216a. Hereinafter, as needed, the portion of the support frame 216 located on the -Y side of the cell stack 102G as shown in FIG. 4 will be referred to as a second support portion 216b.

[0028] As shown in FIGS. 3 and 4, a first protrusion 122 is provided on the outer surface on the +Y side of the third plate 113. The first protrusion 122 protrudes from the third plate 113 toward the +Y side. The first protrusion 122 is disposed on the +Z side of the +Z side surface of the first support portion 216a. The first protrusion 122 and the first support portion 216a are fastened to each other by a plurality of first bolts 162. As shown in FIG. 3, the plurality of first bolts 162 are aligned in the X direction. However, the number and arrangement of the first bolts 162 are not limited to the example shown in FIG. 3. For example, the first protrusion 122 and the first support portion 216a may be fastened to each other by only a single first bolt 162.

[0029] As shown in FIGS. 3 and 4, a second protrusion 124 is provided on the outer surface on the -Y side of the fourth plate 114. The second protrusion 124 protrudes from the fourth plate 114 toward the -Y side. The second protrusion 124 is disposed on the +Z side of the +Z side surface of the second support portion 216b. The second protrusion 124 and the second support portion 216b are fastened to each other by a plurality of second bolts 164. As shown in FIG. 3, the plurality of second bolts 164 are aligned in the X direction. However, the number and arrangement of the second bolts 164 are not limited to the example shown in FIG. 3. For example, the second protrusion 124 and the second support portion 216b may be fastened to each other by only a single second bolt 164.

[0030] As shown in FIGS. 4 and 5 , the thermally conductive plate 218 is located on the +Z side of the +Z-side surface of the lower plate 212. In this embodiment, the thermally conductive plate 218 is a cooling plate through which a refrigerant such as water flows. That is, the thermally conductive plate 218 serves as a cooling body that cools the battery module 100. However, the thermally conductive plate 218 may be a heating plate that heats itself when the battery pack 10 is used in a relatively low temperature, such as in a cold region or in winter. That is, the thermally conductive plate 218 may be a heating body that heats the battery module 100 when the battery pack 10 is used in a relatively low temperature. The battery module 100 is mounted on the +Z side of the +Z-side surface of the thermally conductive plate 218, with the filler 150 at least partially positioned between the sixth plate 116 and the thermally conductive plate 218. Therefore, the thermally conductive plate 218 serves as a thermal conductor that at least partially overlaps with the battery module 100 in the Z direction. The filler 150 is compressed in the Z direction by the −Z side surface of the sixth plate 116 and the +Z side surface of the heat conduction plate 218 .

[0031] In the embodiment, the filler 150 is a thermally conductive adhesive. Examples of the filler 150 include modified silicone-based coating fillers, urethane-based coating fillers, and acrylic-based coating fillers. Therefore, the −Z side surface of the sixth plate 116 and the +Z side surface of the thermally conductive plate 218 are physically bonded via the filler 150. This makes it possible to prevent the sixth plate 116 and the thermally conductive plate 218 from shifting relative to each other, compared to when the filler 150 is not provided. Furthermore, the −Z side surface of the sixth plate 116 and the +Z side surface of the thermally conductive plate 218 are thermally bonded via the filler 150. This makes it possible to more easily dissipate heat generated in the battery module 100 to the thermally conductive plate 218 via the thermally conductive adhesive 116a, the sixth plate 116, and the filler 150, compared to when the filler 150 is not provided.

[0032] As shown in FIG. 6, the surface of the sixth plate 116 on which the thermally conductive adhesive 116a is located and the surface of the sixth plate 116 opposite to the surface on which the thermally conductive adhesive 116a is located have irregularities. Therefore, as shown in FIGS. 5 and 6, the +Z side surface of the sixth plate 116 defines a plurality of first recesses 117a, and as shown in FIG. 5, the -Z side surface of the sixth plate 116 defines a plurality of second recesses 117b. The sixth plate 116 is, for example, a metal plate. The irregularities of the sixth plate 116 are formed by, for example, pressing, bending, or rolling. In the example shown in FIG. 5, a protrusion having a shape approximately similar to that of the first recess 117a is formed in a portion of the -Z side surface of the sixth plate 116 that is located on the -Z side relative to the first recess 117a. Similarly, a convex portion having a shape substantially similar to that of the second recess 117b is formed on the +Z side surface of the sixth plate 116 in a portion located on the +Z side of the second recess 117b.

[0033] In the embodiment, the contact area between the sixth plate 116 and the thermally conductive adhesive 116a can be increased compared to when the +Z side surface of the sixth plate 116 is a flat surface perpendicular to the Z direction, and heat generated from the battery cell 102 can be efficiently dissipated. In the example shown in FIG. 5, the thermally conductive adhesive 116a is at least partially embedded in the first recess 117a. Furthermore, in the embodiment, the contact area between the sixth plate 116 and the filler 150 can be increased compared to when the -Z side surface of the sixth plate 116 is a flat surface perpendicular to the Z direction, and heat generated from the battery cell 102 can be efficiently dissipated. In the example shown in FIG. 5, the filler 150 is at least partially embedded in the second recess 117b.

[0034] In the embodiment, as shown in FIG. 6 , the multiple first recesses 117a extend in the Y direction when viewed from the Z direction. That is, the concaves and convexes of the sixth plate 116 extend in the Y direction when viewed from the Z direction. As shown in FIG. 4 , in the cell stack 102G, the multiple battery cells 102 are aligned in the Y direction. Therefore, compared to when the concaves and convexes of the sixth plate 116 extend in the X direction, it is easier to stably place the cell stack 102G on the sixth plate 116. However, the shape of the concaves and convexes of the sixth plate 116 is not limited to the example shown in FIG. 6 . For example, when viewed from the Z direction, the concaves and convexes of the sixth plate 116 may extend non-perpendicularly in the Y direction. For example, when viewed from the Z direction, the concaves and convexes of the sixth plate 116 may extend obliquely with respect to the X direction. When the unevenness of the sixth plate 116 extends non-perpendicularly in the Y direction as viewed from the Z direction, it becomes easier to stably place the cell stack 102G on the sixth plate 116 compared to when the unevenness of the sixth plate 116 extends in the X direction as viewed from the Z direction. However, when viewed from the Z direction, the unevenness of the sixth plate 116 may extend in the X direction.

[0035] FIG. 7 is a diagram showing a modification of FIG.

[0036] As shown in FIG. 7 , the plurality of first recesses 117a may be at least partially scattered when viewed from the Z direction. That is, the concaves and convexes of the sixth plate 116 may be at least partially scattered when viewed from the Z direction. In the example shown in FIG. 7 , the plurality of first recesses 117a are arranged in a staggered pattern when viewed from the Z direction. Therefore, compared to when the first recesses 117a extend in the X direction when viewed from the Z direction, it is easier to stably place the cell stack 102G on the sixth plate 116. The layout of the plurality of first recesses 117a is not limited to the example shown in FIG. 7 . As long as it is easier to stably place the cell stack 102G on the sixth plate 116, the plurality of first recesses 117a may be scattered in a layout different from that shown in FIG. 7 .

[0037] 7, unevenness exists on both the +Z side surface and the -Z side surface of the sixth plate 116. Therefore, compared to when the +Z side surface of the sixth plate 116 is a flat surface perpendicular to the Z direction, the contact area between the sixth plate 116 and the thermally conductive adhesive 116a can be increased, allowing for more efficient dissipation of heat generated from the battery cells 102. Furthermore, compared to when the -Z side surface of the sixth plate 116 is a flat surface perpendicular to the Z direction, the contact area between the sixth plate 116 and the filler 150 can be increased, allowing for more efficient dissipation of heat generated from the battery cells 102.

[0038] Although the embodiments and modifications of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0039] In the embodiment and modified examples, a thermally conductive adhesive 116a is positioned between the cell stack 102G and the sixth plate 116. However, the thermally conductive material that thermally couples the cell stack 102G and the sixth plate 116 to each other is not limited to the thermally conductive adhesive 116a. For example, the thermally conductive material does not have to be an adhesive. [Explanation of symbols]

[0040] 10 battery pack, 100 battery module, 102 battery cell, 102G cell stack, 104 compression pad, 110 module housing, 111 first plate, 112 second plate, 113 third plate, 114 fourth plate, 115 fifth plate, 115a structural adhesive, 116 sixth plate, 116a thermally conductive adhesive, 117a first recess, 117b second recess, 122 first protrusion, 124 second protrusion, 150 filler, 162 first bolt, 164 second bolt, 200 pack housing, 210 lower case, 212 lower plate, 214 side frame, 215 terminal, 216 support frame, 216a first support portion, 216b second support portion, 218 thermally conductive plate, 220 upper case, 230 sealing material, 250 storage space

Claims

1. A battery cell; a housing that houses the battery cell; a thermally conductive material at least partially positioned between the battery cell and the housing; Equipped with The battery module has irregularities on a surface of the housing on which the thermally conductive material is located and on a surface of the housing opposite to the side on which the thermally conductive material is located.

2. A plurality of the battery cells are arranged in a predetermined direction, The battery module according to claim 1 , wherein the irregularities at least partially extend non-perpendicular to the predetermined direction.

3. The battery module according to claim 1 , wherein a plurality of the projections and recesses are at least partially interspersed.

4. The battery module according to any one of claims 1 to 3; a thermal conductor at least partially overlapping the battery module; Equipped with The battery pack, wherein the irregularities of the housing are at least partially located between the thermally conductive material and the thermal conductor.

5. The battery pack of claim 4 , further comprising a filler located at least partially between the housing and the thermal conductor.

Images