Battery module

Abstract

To improve the degree of freedom in position of a portion, of a flexible substrate, electrically connected to a battery cell.SOLUTION: A battery module 100 comprises: a battery cell 110; a protector 121; and a flexible substrate 123 which is electrically connected to the battery cell 110 and is fitted to the protector 121. The flexible substrate 123 and the protector 121 are fitted to each other via a structure which movably supports the flexible substrate 123 on the protector 121.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] In recent years, various battery modules have been developed. Each battery module includes battery cells.

[0003] Patent Document 1 describes an FPC (flexible printed circuit). A part of the FPC overlaps with a piece. The piece has pins that pass through holes provided in the FPC. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-268173 A Summary of the Invention [Problem to be solved by the invention]

[0005] The flexible substrate and the support may be attached to each other, and the flexible substrate and the battery cell may be electrically connected to each other. However, if the flexible substrate is fixed to the support, it may be difficult to improve the degree of freedom of the position of the portion of the flexible substrate that is electrically connected to the battery cell.

[0006] One example of an object of the present invention is to improve the degree of freedom in the position of a portion of a flexible substrate that is electrically connected to a battery cell. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0007] One aspect of the present invention is as follows. 1. A battery cell; A support; A flexible substrate electrically connected to the battery cell and attached to the support; Equipped with The flexible substrate and the support are attached to each other via a structure that movably supports the flexible substrate on the support. 2. The battery cell has a tab; The support has a frame that at least partially surrounds the tab, 2. The battery module according to claim 1, wherein the structure is provided on the frame body. 3. A battery module described in 1. or 2., wherein the structure penetrates the flexible substrate. 4. The battery module described in any one of 1. to 3., wherein the structure supports the flexible substrate on the support body so that the flexible substrate can swing. 5. The battery module described in any one of 1. to 4., wherein the structure supports the flexible substrate slidably on the support body. 6. The battery module described in any one of 1. to 5., wherein the flexible substrate has a fuse electrically connected to the battery cell. Effect of the Invention

[0008] According to the above-described aspects of the present invention, it is possible to improve the degree of freedom in the position of the portion of the flexible substrate that is electrically connected to the battery cell. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of a battery module according to the embodiment; [Diagram 2] FIG. 2 is a perspective view of a portion of a battery module according to the embodiment. [Diagram 3] FIG. 2 is an enlarged view of a flexible substrate according to an embodiment. [Figure 4] FIG. 4 is a diagram showing a modification of FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments and modifications of the present invention will be described with reference to the drawings. In all the drawings, similar components are given similar reference numerals and descriptions thereof will be omitted as appropriate.

[0011] Fig. 1 is a perspective view of a battery module 100 according to an embodiment. Fig. 2 is a perspective view of a portion of the battery module 100 according to an embodiment. Fig. 3 is an enlarged view of a flexible substrate 123 according to an embodiment. For the sake of explanation, a plurality of voltage detection terminals 122, a plurality of flexible substrates 123, and a plurality of voltage detection lines 124 shown in Fig. 2 have been removed in Fig. 1.

[0012] For the purpose of explanation, the X, Y, and Z directions are shown in each figure. The X direction indicates the front-rear direction of the battery module 100. The Y direction is perpendicular to the X direction. The Y direction indicates the left-right direction of the battery module 100. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-down direction of the battery module 100. An arrow pointing to the X direction, an arrow pointing to the Y direction, and an arrow pointing to the Z direction indicate the rear, left, and up directions of the battery module 100, respectively. In FIG. 3, a white circle with an X indicating the Y direction indicates that the arrow pointing to the direction indicated by the white circle extends from the front to the back of the paper. Hereinafter, as necessary, the tip side of the arrow indicating the X direction will be referred to as the +X side, the opposite side of the tip of the arrow indicating the X direction will be referred to as the -X side, the tip side of the arrow indicating the Y direction will be referred to as the +Y side, the opposite side of the tip of the arrow indicating the Y direction will be referred to as the -Y side, the tip side of the arrow indicating the Z direction will be referred to as the +Z side, and the opposite side of the tip of the arrow indicating the Z direction will be referred to as the -Z side. The relationship between the X direction, Y direction, and Z direction and the front-rear direction, left-right direction, and up-down direction of the battery module 100 is not limited to the above example.

[0013] The battery module 100 will be described with reference to Fig. 1, and if necessary, with reference to Fig. 2. The battery module 100 includes a plurality of battery cells 110 and a voltage detection device 120.

[0014] The multiple battery cells 110 are stacked in the Y direction. Hereinafter, as necessary, the multiple battery cells 110 stacked in the Y direction will be referred to as a stack of battery cells 110. The dimension of each battery cell 110 in the X direction is the dimension in the longitudinal direction of each battery cell 110. The dimension of each battery cell 110 in the Z direction is the dimension in the lateral direction of each battery cell 110. The dimension of each battery cell 110 in the Y direction is the dimension in the thickness direction of each battery cell 110. The shape of each battery cell 110 is not limited to this example.

[0015] Each battery cell 110 includes a battery element (not shown), an exterior material 112, a positive electrode tab 114, and a negative electrode tab 116. In one example, the battery element includes a plurality of positive electrodes and a plurality of negative electrodes (not shown) alternately stacked in the Y direction, and a separator (not shown) located between the positive electrodes and the negative electrodes adjacent in the Y direction. The exterior material 112 seals the battery element and an electrolyte (not shown). The positive electrode tab 114 is electrically connected to the positive electrode of the battery element. The positive electrode tab 114 is drawn out from one of the two sides of the exterior material 112 in the X direction. The negative electrode tab 116 is electrically connected to the negative electrode of the battery element. The negative electrode tab 116 is drawn out from the other side of the exterior material 112 in the X direction. However, the structure of each battery cell 110 is not limited to this example.

[0016] Each battery cell 110 may be an all-solid-state battery. In an all-solid-state battery, a solid electrolyte layer is provided in a portion corresponding to a separator. An all-solid-state battery does not contain an electrolyte. Hereinafter, unless otherwise specified, each battery cell 110 will be described as a battery cell containing an electrolyte.

[0017] The battery cells 110 are electrically connected in series and parallel. Specifically, cell groups including at least two battery cells 110 adjacent to each other in the Y direction and connected in parallel are stacked in the Y direction and connected in series. On the -X side of the stack of battery cells 110, a positive electrode tab 114 drawn from a battery cell 110 of one cell group connected in parallel and a negative electrode tab 116 drawn from a battery cell 110 of another cell group connected in parallel are electrically connected to each other, and a tab group 118 including the positive electrode tab 114 and the negative electrode tab 116 is located. The positive electrode tab 114 and the negative electrode tab 116 in the tab group 118 are joined to each other by, for example, laser welding. The tab group 118 is also located on the +X side of the stack of battery cells 110. Thus, a plurality of cell groups are connected in series from the cell group located at one end side of the stack of battery cells 110 in the Y direction to the cell group located at the other end side of the stack of battery cells 110 in the Y direction. Hereinafter, as necessary, the tab group 118 located on the -X side of the stack of battery cells 110 will be referred to as the -X side tab group 118, and the tab group 118 located on the +X side of the stack of battery cells 110 will be referred to as the +X side tab group 118.

[0018] The electrical connection of the multiple battery cells 110 is not limited to the above example. For example, a stack of the battery cells 110 may be formed by connecting single battery cells 110 in series.

[0019] Voltage detection device 120 detects the voltages of multiple -X side tab groups 118. As shown in Figures 1 and 2, voltage detection device 120 has a protector 121, multiple voltage detection terminals 122, multiple flexible substrates 123, multiple voltage detection lines 124, a positive electrode bus bar 125, and a negative electrode bus bar 126.

[0020] The protector 121 covers the -X side portion of the stack of battery cells 110. The protector 121 is, for example, an insulator such as resin. The protector 121 has a plurality of frame bodies 121f. Each of the plurality of -X side tab groups 118 is exposed toward the -X side from an opening defined by each of the plurality of frame bodies 121f. Each of the plurality of frame bodies 121f at least partially surrounds each of the plurality of -X side tab groups 118. Thus, each frame body 121f can protect each tab group 118 from members external to each frame body 121f.

[0021] Each of the multiple voltage detection terminals 122 is located on the -X side of each of the multiple -X side tab groups 118. Each voltage detection terminal 122 is, for example, a conductor such as metal. The +X side surface of each voltage detection terminal 122 and the -X side surface of each -X side tab group 118 are joined to each other by a joining method such as laser welding. Therefore, each voltage detection terminal 122 and each -X side tab group 118 are electrically connected to each other. Therefore, the voltage detection device 120 can detect the voltage of each -X side tab group 118 by each voltage detection terminal 122. The multiple voltage detection terminals 122 are held together by a protector 121. Therefore, by installing the protector 121 at an appropriate position with respect to the stack of battery cells 110, each of the multiple voltage detection terminals 122 can be disposed at an appropriate position with respect to each of the multiple -X side tab groups 118.

[0022] The positive bus bar 125 is disposed at the end portion on the -Y side of the protector 121. The positive bus bar 125 is electrically connected to a positive tab 114 drawn out to the -X side from a battery cell 110 of a cell group located at the end portion on the -Y side of the stack of battery cells 110. The positive bus bar 125 functions as an external terminal for electrically connecting the battery module 100 to an external device such as another battery module.

[0023] The negative bus bar 126 is disposed at the end portion on the +Y side of the protector 121. The negative bus bar 126 is electrically connected to a negative tab 116 drawn out to the -X side from a battery cell 110 of a cell group located at the end portion on the +Y side of the stack of battery cells 110. The negative bus bar 126 functions as an external terminal for electrically connecting the battery module 100 to an external device such as another battery module.

[0024] In the example shown in FIG. 1, the positive electrode tab 114 at the end of the multiple cell groups connected in series is drawn toward the -X side from the battery cell 110 of the cell group located at the end side of the -Y side of the stack of battery cells 110, and the negative electrode tab 116 at the end of the multiple cell groups connected in series is drawn toward the -X side from the battery cell 110 of the cell group located at the end side of the +Y side of the stack of battery cells 110. Thus, the positive electrode bus bar 125 is disposed on the -X side and the -Y side of the stack of battery cells 110, and the negative electrode bus bar 126 is disposed on the -X side and the +Y side of the stack of battery cells 110. However, the arrangement of the positive electrode tab 114 and the negative electrode tab 116 at the end of the multiple cell groups connected in series may differ depending on the number of battery cells 110 included in the stack of battery cells 110. For example, there are cases where the positive electrode tab 114 at the end of a group of multiple cells connected in series is pulled out toward the -X side from the battery cell 110 of the cell group located at the -Y side end of the stack of battery cells 110, and the negative electrode tab 116 at the end of a group of multiple cells connected in series is pulled out toward the +X side from the battery cell 110 of the cell group located at the +Y side end of the stack of battery cells 110. In this case, the positive electrode bus bar 125 is disposed on the -X side and the -Y side of the stack of battery cells 110, and the negative electrode bus bar 126 is disposed on the +X side and the +Y side of the stack of battery cells 110.

[0025] The flexible substrate 123 will be described with reference to FIGS.

[0026] As shown in FIG. 2, flexible substrate 123 is disposed such that the longitudinal direction of flexible substrate 123 is approximately parallel to the Z direction and the direction perpendicular to flexible substrate 123 is approximately parallel to the Y direction.

[0027] 2, the voltage detection terminal 122 includes a first conductor portion 122f and a second conductor portion 122s. The +Y side end portion of the first conductor portion 122f and the -X side end portion of the second conductor portion 122s are connected to each other in a state in which the direction perpendicular to the first conductor portion 122f is approximately parallel to the X direction and the direction perpendicular to the second conductor portion 122s is approximately parallel to the Y direction. For example, the voltage detection terminal 122 is formed by bending the first conductor portion 122f and the second conductor portion 122s at approximately a right angle to each other.

[0028] 2 and 3, a protrusion 121p penetrates a portion of the flexible substrate 123 on the +Z side. The protrusion 121p is provided on the inner surface of the portion of the frame 121f on the +Y side. The flexible substrate 123 and the frame 121f are attached to each other via the protrusion 121p. In a state in which the flexible substrate 123 and the frame 121f are attached to each other, the protector 121 including the frame 121f serves as a support for supporting the flexible substrate 123. However, the support for supporting the flexible substrate 123 may be a member different from the protector 121.

[0029] The protrusion 121p is structured to movably support the flexible substrate 123 on the frame body 121f. Specifically, the protrusion 121p is structured to swingably support the flexible substrate 123 on the frame body 121f. Therefore, in a state in which the -Z side portion of the flexible substrate 123 and the second conductor portion 122s of the voltage detection terminal 122 are not joined to each other, the flexible substrate 123 can swing around the protrusion 121p. Therefore, compared to a case in which the flexible substrate 123 is fixedly fixed to the frame body 121f, the degree of freedom of the position of the -Z side portion of the flexible substrate 123 that is electrically connected to the battery cell 110 can be improved. Therefore, compared to a case in which the flexible substrate 123 is fixedly fixed to the frame body 121f, the flexible substrate 123 can be made to more easily follow the displacement of the voltage detection terminal 122.

[0030] The -Y side surface of the -Z side portion of flexible substrate 123 and the +Y side surface of second conductor portion 122s are electrically connected to each other. The -Y side surface of the -Z side portion of flexible substrate 123 and the +Y side surface of second conductor portion 122s are joined to each other by a joining method such as laser welding or ultrasonic joining.

[0031] The +Z side portion of the flexible substrate 123 and one end portion of the voltage detection line 124 are electrically connected to each other. Therefore, the voltage detection terminal 122 and the voltage detection line 124 are electrically connected to each other via the flexible substrate 123.

[0032] Flexible substrate 123 may have a fuse electrically connected to voltage detection terminal 122 and voltage detection line 124. For example, the fuse is configured by a conductor pattern provided on a base film such as a resin film that configures flexible substrate 123. The conductor pattern provided on flexible substrate 123 may configure only the fuse. When a current of a predetermined value or more flows through the fuse provided on flexible substrate 123, the fuse provided on flexible substrate 123 melts. Therefore, when a current of a predetermined value or more flows through the fuse provided on flexible substrate 123, the current between voltage detection terminal 122 and voltage detection line 124 can be interrupted.

[0033] FIG. 4 is a diagram showing a modification of FIG.

[0034] The frame body 121f is provided with a first protrusion 121p1 and a second protrusion 121p2. The +Z side portion and the -Z side portion of the flexible substrate 123 define a first hole 123h1 and a second hole 123h2, respectively. The first protrusion 121p1 and the second protrusion 121p2 pass through the first hole 123h1 and the second hole 123h2, respectively. The flexible substrate 123 and the frame body 121f are attached to each other via the first protrusion 121p1 and the second protrusion 121p2.

[0035] The first protrusion 121p1 and the second protrusion 121p2 are structured to movably support the flexible substrate 123 on the frame body 121f. Specifically, the first protrusion 121p1 and the second protrusion 121p2 are structured to slidably support the flexible substrate 123 on the frame body 121f. In the modified example, the dimension in the X direction of the first hole 123h1 and the dimension in the X direction of the second hole 123h2 are larger than the dimension in the X direction of the first protrusion 121p1 and the dimension in the X direction of the second protrusion 121p2, respectively. Therefore, in a state in which the flexible substrate 123 and the voltage detection terminal 122 are not joined to each other, the flexible substrate 123 is slidable in the X direction. Therefore, compared to a case in which the flexible substrate 123 is fixed immovably to the frame body 121f, the degree of freedom of the position of the -Z side portion of the flexible substrate 123 can be improved. Therefore, flexible substrate 123 can be made to follow the displacement of voltage detection terminal 122 more easily than in the case where flexible substrate 123 is fixed immovably to frame 121f.

[0036] Although the embodiment and modified examples of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted. [Explanation of symbols]

[0037] 100 battery module, 110 battery cell, 112 exterior material, 114 positive electrode tab, 116 negative electrode tab, 118 tab group, 120 voltage detection device, 121 protector, 121f frame, 121p protrusion, 121p1 first protrusion, 121p2 second protrusion, 122 voltage detection terminal, 122f first conductor portion, 122s second conductor portion, 123 flexible substrate, 123h1 first hole, 123h2 second hole, 124 voltage detection line, 125 positive electrode bus bar, 126 negative electrode bus bar

Claims

1. A battery cell; A support; A flexible substrate electrically connected to the battery cell and attached to the support; Equipped with The flexible substrate and the support are attached to each other via a structure that movably supports the flexible substrate on the support.

2. The battery cell has a tab. The support has a frame that at least partially surrounds the tab, The battery module according to claim 1 , wherein the structure is provided on the frame.

3. The battery module according to claim 1 or 2, wherein the structure penetrates the flexible substrate.

4. The battery module according to claim 1 , wherein the structure supports the flexible substrate on the support body so as to be capable of swinging.

5. The battery module according to claim 1 or 2, wherein the structure slidably supports the flexible substrate on the support.

6. The battery module according to claim 1 , wherein the flexible substrate has fuses electrically connected to the battery cells.

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