Battery module

Abstract

A battery module (100A) comprises a battery cell (110), a protector (121), and a flexible substrate (123A) electrically connected to the battery cell (110) and attached to the protector (121). The flexible substrate (123A) and the protector (121) are attached to each other via a structure in which the flexible substrate (123A) is movably supported by the protector (121).

Description

Battery module

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

[0002] In recent years, various battery modules have been developed, each of which includes battery cells.

[0003] Patent Document 1 describes an FPC (flexible printed circuit), in which a portion of the FPC overlaps with a piece, and the piece has pins that pass through holes provided in the FPC.

[0004] Patent Document 2 describes an FPC (flexible printed circuit), which has a slit formed therein.

[0005] JP-A-2005-268173 JP-A-5-48218

[0006] (Aspect 1) A flexible substrate and a support member are attached to each other, and the flexible substrate and the battery cell are electrically connected to each other. However, if the flexible substrate is fixed to the support member, it may be difficult to improve the degree of freedom in the position of the portion of the flexible substrate that is electrically connected to the battery cell.

[0007] One example of an object of the first aspect of the present invention is to improve the degree of freedom in the position of the portion of the flexible substrate that is electrically connected to the battery cell. Other objects of the first aspect of the present invention will become apparent from the description of this specification.

[0008] (Mode 2) A flexible substrate and a support body may be attached to each other, and the flexible substrate and the battery cell may be electrically connected to each other. However, if the portion of the support body where the flexible substrate is attached and the portion of the battery cell where the flexible substrate is electrically connected face in different directions, it may be difficult to route the flexible substrate between the portion of the flexible substrate attached to the support body and the portion of the flexible substrate electrically connected to the battery cell.

[0009] One example of an object of the second aspect of the present invention is to facilitate routing of the flexible substrate between the portion of the flexible substrate attached to the support and the portion of the flexible substrate electrically connected to the battery cell. Other objects of the second aspect of the present invention will become apparent from the description of this specification.

[0010] Aspect 1 of the present invention is as follows. 1.1 A battery module comprising: a battery cell; a support; and a flexible substrate electrically connected to the battery cell and attached to the support, wherein the flexible substrate and the support are attached to each other via a structure that movably supports the flexible substrate on the support. 1.2 The battery module according to 1.1, wherein the battery cell has a tab; the support has a frame body that at least partially surrounds the tab; and the structure is provided on the frame body. 1.3 The battery module according to 1.1 or 1.2, wherein the structure penetrates the flexible substrate. 1.4 The battery module according to any one of 1.1 to 1.3, wherein the structure supports the flexible substrate on the support body so that it can swing. 1.5 The battery module according to any one of 1.1 to 1.4, wherein the structure supports the flexible substrate on the support body so that it can slide. 1.6 The battery module according to any one of 1.1 to 1.5, wherein the flexible substrate has a fuse electrically connected to the battery cell.

[0011] Aspect 2 of the present invention is as follows. 2.1 A battery module comprising: a battery cell; a support; and a flexible substrate electrically connected to the battery cell and attached to the support, wherein the flexible substrate is at least partially twisted between a portion of the flexible substrate attached to the support and a portion of the flexible substrate electrically connected to the battery cell. 2.2 The battery module according to 2.1, wherein the battery cell has a tab, and the support has a frame body at least partially surrounding the tab, and the flexible substrate and the frame body are attached to each other. 2.3 The battery module according to 2.1 or 2.2, wherein the flexible substrate has a fuse electrically connected to the battery cell. 2.4 The battery module according to any one of 2.1 to 2.3, wherein the flexible substrate defines a slit between the portion of the flexible substrate attached to the support and the portion of the flexible substrate electrically connected to the battery cell.

[0012] According to the first aspect 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.

[0013] According to the second aspect of the present invention, it is possible to easily route the flexible substrate between the portion of the flexible substrate attached to the support and the portion of the flexible substrate electrically connected to the battery cell.

[0014] 3 is a perspective view of a battery module according to embodiment 1. FIG. 4 is a perspective view of a portion of a battery module according to embodiment 1. FIG. 5 is an enlarged view of a flexible substrate according to embodiment 1. FIG. 6 is a diagram showing a modification of FIG. 3. FIG. 7 is a perspective view of a battery module according to embodiment 2. FIG. 8 is a perspective view of a portion of a battery module according to embodiment 2. FIG. 9 is a perspective view of a flexible substrate according to embodiment 2.

[0015] Hereinafter, a first embodiment and modifications of the present invention will be described with reference to the drawings. In all the drawings, like components are denoted by like reference numerals, and descriptions thereof will be omitted as appropriate.

[0016] Fig. 1 is a perspective view of a battery module 100A according to embodiment 1. Fig. 2 is a perspective view of a portion of the battery module 100A according to embodiment 1. Fig. 3 is an enlarged view of a flexible substrate 123A according to embodiment 1. For the sake of explanation, a plurality of voltage detection terminals 122A, a plurality of flexible substrates 123A, and a plurality of voltage detection lines 124 shown in Fig. 2 have been removed from Fig. 1.

[0017] 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 module 100A. The Y direction is perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery module 100A. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-to-down direction of the battery module 100A. The arrow pointing to the X direction, the arrow pointing to the Y direction, and the arrow pointing to the Z direction indicate the rear, left, and up directions of the battery module 100A, respectively. In FIG. 3, a white circle with an X indicating the Y direction indicates that the arrow pointing in the direction indicated by the white circle extends from the front to the back of the page. 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 100A is not limited to the above example.

[0018] The battery module 100A will be described with reference to Fig. 1 and, if necessary, Fig. 2. The battery module 100A includes a plurality of battery cells 110 and a voltage detection device 120.

[0019] The plurality of battery cells 110 are stacked in the Y direction. Hereinafter, as necessary, the plurality of 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.

[0020] 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) stacked alternately in the Y direction, and a separator (not shown) positioned between adjacent positive electrodes and negative electrodes 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 pulled out from one of both 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 pulled out from the other side of both sides of the exterior material 112 in the X direction. However, the structure of each battery cell 110 is not limited to this example.

[0021] 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 solution. Unless otherwise specified, the following description will be given assuming that each battery cell 110 is a battery cell containing an electrolyte solution.

[0022] The multiple battery cells 110 are electrically connected in a combination of 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, forming a tab group 118 including the positive electrode tab 114 and the negative electrode tab 116. 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. A tab group 118 is also located on the +X side of the stack of battery cells 110. Thus, multiple cell groups are connected in series from the cell group located at one end of the stack of battery cells 110 in the Y direction to the cell group located at the other end 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.

[0023] The electrical connection of the plurality of battery cells 110 is not limited to the above example. For example, a stack of battery cells 110 may be configured by connecting single battery cells 110 in series.

[0024] The voltage detection device 120 detects the voltages of the multiple −X side tab groups 118. As shown in Figures 1 and 2, the voltage detection device 120 includes a protector 121, multiple voltage detection terminals 122A, multiple flexible substrates 123A, multiple voltage detection lines 124, a positive bus bar 125, and a negative bus bar 126.

[0025] 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 multiple frame bodies 121f. Each of the multiple -X side tab groups 118 is exposed toward the -X side from an opening defined by each of the multiple frame bodies 121f. Each of the multiple frame bodies 121f at least partially surrounds each of the multiple -X side tab groups 118. Therefore, each frame body 121f can protect each tab group 118 from components external to each frame body 121f.

[0026] Each of the multiple voltage detection terminals 122A is located on the -X side of each of the multiple -X side tab groups 118. Each voltage detection terminal 122A is a conductor, such as metal. The +X side surface of each voltage detection terminal 122A 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 122A 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 using each voltage detection terminal 122A. The multiple voltage detection terminals 122A are held together by a protector 121. Therefore, by installing the protector 121 in an appropriate position relative to the stack of battery cells 110, each of the multiple voltage detection terminals 122A can be positioned appropriately relative to each of the multiple -X side tab groups 118.

[0027] The positive electrode bus bar 125 is disposed at the end portion on the -Y side of the protector 121. The positive electrode bus bar 125 is electrically connected to a positive electrode tab 114 that is drawn out to the -X side from a battery cell 110 of a cell group that is located at the end portion on the -Y side of the stack of battery cells 110. The positive electrode bus bar 125 functions as an external terminal for electrically connecting the battery module 100A to an external device such as another battery module.

[0028] The negative electrode bus bar 126 is disposed at the end portion on the +Y side of the protector 121. The negative electrode bus bar 126 is electrically connected to the negative electrode tab 116 that is drawn out to the −X side from the battery cell 110 of the cell group located at the end portion on the +Y side of the stack of battery cells 110. The negative electrode bus bar 126 functions as an external terminal for electrically connecting the battery module 100A to an external device such as another battery module.

[0029] 1 , the positive electrode tab 114 at the end of a group of multiple cells connected in series is drawn 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 drawn 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. 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 a group of multiple cells 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 arranged on the −X side and the −Y side of the stack of battery cells 110, and the negative electrode bus bar 126 is arranged on the +X side and the +Y side of the stack of battery cells 110.

[0030] The flexible substrate 123A will be described with reference to FIGS.

[0031] As shown in FIG. 2, the flexible substrate 123A is disposed such that the longitudinal direction of the flexible substrate 123A is approximately parallel to the Z direction and the direction perpendicular to the flexible substrate 123A is approximately parallel to the Y direction.

[0032] 2, the voltage detection terminal 122A 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 with the direction perpendicular to the first conductor portion 122f being approximately parallel to the X direction and the direction perpendicular to the second conductor portion 122s being approximately parallel to the Y direction. For example, the voltage detection terminal 122A is formed by bending the first conductor portion 122f and the second conductor portion 122s at approximately right angles to each other.

[0033] 2 and 3, a protrusion 121p penetrates the +Z side portion of the flexible substrate 123A. The protrusion 121p is provided on the inner surface of the +Y side portion of the frame body 121f. The flexible substrate 123A and the frame body 121f are attached to each other via the protrusion 121p. When the flexible substrate 123A and the frame body 121f are attached to each other, the protector 121 including the frame body 121f serves as a support body that supports the flexible substrate 123A. However, the support body that supports the flexible substrate 123A may be a member different from the protector 121.

[0034] The protrusion 121p is structured to movably support the flexible substrate 123A on the frame 121f. Specifically, the protrusion 121p is structured to swingably support the flexible substrate 123A on the frame 121f. Therefore, when the -Z side portion of the flexible substrate 123A and the second conductor portion 122s of the voltage detection terminal 122A are not joined to each other, the flexible substrate 123A can swing around the protrusion 121p. Therefore, compared to when the flexible substrate 123A is fixedly attached to the frame 121f, the degree of freedom in the position of the -Z side portion of the flexible substrate 123A that is electrically connected to the battery cell 110 can be improved. Therefore, compared to when the flexible substrate 123A is fixedly attached to the frame 121f, the flexible substrate 123A can more easily follow the displacement of the voltage detection terminal 122A.

[0035] The -Y side surface of the -Z side portion of flexible substrate 123A 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 123A 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 bonding.

[0036] The +Z side portion of the flexible substrate 123A and one end portion of the voltage detection line 124 are electrically connected to each other. Therefore, the voltage detection terminal 122A and the voltage detection line 124 are electrically connected to each other via the flexible substrate 123A.

[0037] The flexible substrate 123A may have a fuse electrically connected to the voltage detection terminal 122A and the voltage detection line 124. For example, the fuse is formed by a conductor pattern provided on a base film, such as a resin film, that constitutes the flexible substrate 123A. The conductor pattern provided on the flexible substrate 123A may constitute only the fuse. When a current equal to or greater than a predetermined value flows through the fuse provided on the flexible substrate 123A, the fuse provided on the flexible substrate 123A melts. Therefore, when a current equal to or greater than a predetermined value flows through the fuse provided on the flexible substrate 123A, the current between the voltage detection terminal 122A and the voltage detection line 124 can be interrupted.

[0038] FIG. 4 is a diagram showing a modification of FIG.

[0039] The frame 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 123A 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 123A and the frame 121f are attached to each other via the first protrusion 121p1 and the second protrusion 121p2.

[0040] The first protrusion 121p1 and the second protrusion 121p2 are structured to movably support the flexible substrate 123A on the frame body 121f. Specifically, the first protrusion 121p1 and the second protrusion 121p2 are structured to slidably support the flexible substrate 123A on the frame body 121f. In this modified example, the X-direction dimensions of the first hole 123h1 and the second hole 123h2 are larger than the X-direction dimensions of the first protrusion 121p1 and the second protrusion 121p2, respectively. Therefore, when the flexible substrate 123A and the voltage detection terminal 122A are not joined to each other, the flexible substrate 123A is slidable in the X-direction. Therefore, compared to when the flexible substrate 123A is fixedly attached to the frame body 121f, the degree of freedom of positioning of the -Z side portion of the flexible substrate 123A can be improved. Therefore, compared to when the flexible substrate 123A is fixed immovably to the frame 121f, the flexible substrate 123A can be made to more easily follow the displacement of the voltage detection terminal 122A.

[0041] Although the first embodiment and the 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.

[0042] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0043] Fig. 5 is a perspective view of a battery module 100B according to embodiment 2. Fig. 6 is a perspective view of a portion of the battery module 100B according to embodiment 2. Fig. 7 is a perspective view of a flexible substrate 123B according to embodiment 2. For the sake of explanation, the plurality of voltage detection terminals 122B, the plurality of flexible substrates 123B, and the plurality of voltage detection lines 124 shown in Fig. 6 have been removed from Fig. 5.

[0044] 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 module 100B. The Y direction is perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery module 100B. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-and-down direction of the battery module 100B. The arrows pointing to the X direction, the Y direction, and the Z direction indicate the rear, left, and up directions of the battery module 100B, respectively. 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 100B is not limited to the above example.

[0045] The battery module 100B will be described with reference to Fig. 5 and, if necessary, Fig. 6. The battery module 100B includes a plurality of battery cells 110 and a voltage detection device 120.

[0046] The plurality of battery cells 110 are stacked in the Y direction. Hereinafter, as necessary, the plurality of 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.

[0047] 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) stacked alternately in the Y direction, and a separator (not shown) positioned between adjacent positive electrodes and negative electrodes 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 pulled out from one of both 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 pulled out from the other side of both sides of the exterior material 112 in the X direction. However, the structure of each battery cell 110 is not limited to this example.

[0048] 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 solution. Unless otherwise specified, the following description will be given assuming that each battery cell 110 is a battery cell containing an electrolyte solution.

[0049] The multiple battery cells 110 are electrically connected in a combination of 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, forming a tab group 118 including the positive electrode tab 114 and the negative electrode tab 116. 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. A tab group 118 is also located on the +X side of the stack of battery cells 110. Thus, multiple cell groups are connected in series from the cell group located at one end of the stack of battery cells 110 in the Y direction to the cell group located at the other end 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.

[0050] The electrical connection of the plurality of battery cells 110 is not limited to the above example. For example, a stack of battery cells 110 may be configured by connecting single battery cells 110 in series.

[0051] The voltage detection device 120 detects the voltages of the plurality of −X side tab groups 118. As shown in Figures 5 and 6, the voltage detection device 120 includes a protector 121, a plurality of voltage detection terminals 122B, a plurality of flexible substrates 123B, a plurality of voltage detection lines 124, a positive bus bar 125, and a negative bus bar 126.

[0052] 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 multiple frame bodies 121f. Each of the multiple -X side tab groups 118 is exposed toward the -X side from an opening defined by each of the multiple frame bodies 121f. Each of the multiple frame bodies 121f at least partially surrounds each of the multiple -X side tab groups 118. Therefore, each frame body 121f can protect each tab group 118 from components external to each frame body 121f.

[0053] Each of the multiple voltage detection terminals 122B is located on the -X side of each of the multiple -X side tab groups 118. Each voltage detection terminal 122B is a conductor, such as metal. The +X side surface of each voltage detection terminal 122B 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 122B 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 using each voltage detection terminal 122B. The multiple voltage detection terminals 122B are held together by a protector 121. Therefore, by installing the protector 121 in an appropriate position relative to the stack of battery cells 110, each of the multiple voltage detection terminals 122B can be positioned appropriately relative to each of the multiple -X side tab groups 118.

[0054] The positive electrode bus bar 125 is disposed at the end portion on the -Y side of the protector 121. The positive electrode bus bar 125 is electrically connected to a positive electrode tab 114 that is drawn out to the -X side from a battery cell 110 of a cell group that is located at the end portion on the -Y side of the stack of battery cells 110. The positive electrode bus bar 125 functions as an external terminal for electrically connecting the battery module 100B to an external device such as another battery module.

[0055] The negative electrode bus bar 126 is disposed at the end portion on the +Y side of the protector 121. The negative electrode bus bar 126 is electrically connected to the negative electrode tab 116 that is drawn out to the −X side from the battery cell 110 of the cell group located at the end portion on the +Y side of the stack of battery cells 110. The negative electrode bus bar 126 functions as an external terminal for electrically connecting the battery module 100B to an external device such as another battery module.

[0056] 5 , the positive electrode tab 114 at the end of a group of multiple cells connected in series is drawn 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 drawn 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. 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 a group of multiple cells 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 arranged on the −X side and the −Y side of the stack of battery cells 110, and the negative electrode bus bar 126 is arranged on the +X side and the +Y side of the stack of battery cells 110.

[0057] The flexible substrate 123B will be described with reference to FIGS.

[0058] 6, flexible substrate 123B is disposed with its longitudinal direction substantially parallel to the Z direction. Flexible substrate 123B is at least partially twisted between the +Z side portion and the −Z side portion of flexible substrate 123B. Flexible substrate 123B is disposed with the direction perpendicular to the +Z side portion of flexible substrate 123B substantially parallel to the Y direction and the direction perpendicular to the −Z side portion of flexible substrate 123B substantially parallel to the X direction.

[0059] As shown in FIG. 6 , the +Y-side surface of the +Z-side portion of flexible substrate 123B and the inner surface of the +Y-side portion of frame 121f are attached to each other. The +Y-side surface of the +Z-side portion of flexible substrate 123B and the inner surface of the +Y-side portion of frame 121f are mechanically attached to each other by mechanical joining such as engagement or clamping. When flexible substrate 123B and frame 121f are attached to each other, protector 121, including frame 121f, serves as a support for flexible substrate 123B. However, the support for flexible substrate 123B may be a member different from protector 121. The method of attaching the +Z-side portion of flexible substrate 123B and frame 121f is not limited to the example shown in FIG. 6 . For example, the +Z-side portion of flexible substrate 123B may be located on the −Y side of the −X-side tab group 118. When the +Z side portion of flexible substrate 123B is positioned on the -Y side of the -X side tab group 118, the -Y side surface of the +Z side portion of flexible substrate 123B and the inner surface of the -Y side portion of frame body 121f may be attached to each other.

[0060] 6, the +X side surface of the -Z side portion of flexible substrate 123B and the -X side surface of voltage detection terminal 122B are electrically connected to each other. Therefore, flexible substrate 123B and the -X side tab group 118 are electrically connected to each other via voltage detection terminal 122B. The +X side surface of the -Z side portion of flexible substrate 123B and the -X side surface of voltage detection terminal 122B are joined to each other by a joining method such as laser welding or ultrasonic bonding. The -Z side portion of flexible substrate 123B may be located between the +X side surface of voltage detection terminal 122B and the -X side surface of the -X side tab group 118. When the -Z side portion of the flexible substrate 123B is located between the +X side surface of the voltage detection terminal 122B and the -X side surface of the -X side tab group 118, the -X side surface and the +X side surface of the -Z side portion of the flexible substrate 123B may be electrically connected to the +X side surface of the voltage detection terminal 122B and the -X side surface of the -X side tab group 118, respectively.

[0061] The +Z side portion of the flexible substrate 123B and one end portion of the voltage detection line 124 are electrically connected to each other. Therefore, the voltage detection terminal 122B and the voltage detection line 124 are electrically connected to each other via the flexible substrate 123B.

[0062] The flexible substrate 123B may have a fuse electrically connected to the voltage detection terminal 122B and the voltage detection line 124. For example, the fuse is formed by a conductor pattern provided on a base film, such as a resin film, that constitutes the flexible substrate 123B. The conductor pattern provided on the flexible substrate 123B may constitute only the fuse. When a current equal to or greater than a predetermined value flows through the fuse provided on the flexible substrate 123B, the fuse provided on the flexible substrate 123B melts. Therefore, when a current equal to or greater than a predetermined value flows through the fuse provided on the flexible substrate 123B, the current between the voltage detection terminal 122B and the voltage detection line 124 can be interrupted.

[0063] 6, the portion of frame 121f to which the +Z side portion of flexible substrate 123B is attached and the portion of -X side tab group 118 to which the -Z side portion of flexible substrate 123B is electrically connected are oriented in different directions. Specifically, the portion of frame 121f to which the +Z side portion of flexible substrate 123B is attached faces the -Y side, while the portion of -X side tab group 118 to which the -Z side portion of flexible substrate 123B is electrically connected faces the -X side. In the second embodiment, flexible substrate 123B is at least partially twisted between the +Z side portion of flexible substrate 123B attached to frame 121f and the -Z side portion electrically connected to -X side tab group 118 of flexible substrate 123B. Therefore, by at least partially twisting flexible substrate 123B, it is possible to easily route flexible substrate 123B between the +Z side portion attached to frame body 121f of flexible substrate 123B and the -Z side portion electrically connected to tab group 118 on the -X side of flexible substrate 123B.

[0064] 6, the +Z side portion and the −Z side portion of the flexible substrate 123B face in directions that differ by 90° when viewed from the Z direction, depending on the portion of the frame 121f where the flexible substrate 123B is attached and the portion of the battery cell 110 where the flexible substrate 123B is electrically connected. However, the +Z side portion and the −Z side portion of the flexible substrate 123B may face in directions that differ by an angle other than 90° when viewed from the Z direction, depending on the portion of the frame 121f where the flexible substrate 123B is attached and the portion of the battery cell 110 where the flexible substrate 123B is electrically connected.

[0065] As shown in FIG. 7 , the flexible substrates 123B define multiple slits 123s between the −Z side and +Z side portions of each flexible substrate 123B. The multiple slits 123s are arranged approximately parallel to the longitudinal direction of the flexible substrates 123B. Each slit 123s may penetrate the flexible substrate 123B in a direction perpendicular to the flexible substrate 123B, or may be formed on the surface of the flexible substrate 123B without penetrating the flexible substrate 123B in a direction perpendicular to the flexible substrate 123B. When slits 123s are provided, the flexible substrate 123B can be more easily twisted between the −Z side and +Z side portions of the flexible substrate 123B compared to when slits 123s are not provided. However, the flexible substrates 123B do not necessarily have to have slits 123s. Alternatively, each flexible substrate 123B may have only one slit 123s.

[0066] Although the second embodiment of the present invention has been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0067] This application claims priority based on Japanese Patent Application No. 2023-106728 filed on June 29, 2023, and Japanese Patent Application No. 2023-106727 filed on June 29, 2023, the disclosures of which are incorporated herein in their entireties.

[0068] 100A, 100B 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, 122A, 122B Voltage detection terminal, 122f First conductor portion, 122s Second conductor portion, 123A, 123B Flexible substrate, 123h1 First hole, 123h2 Second hole, 123s Slit, 124 Voltage detection line, 125 Positive electrode bus bar, 126 Negative electrode bus bar

Claims

1. A battery module comprising: a battery cell; a support; and a flexible substrate electrically connected to the battery cell and attached to the support, wherein 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 module according to claim 1, wherein the battery cells have tabs, the support has a frame body that at least partially surrounds the tabs, and the structure is provided on the frame body.

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

4. A battery module according to any one of claims 1 to 3, wherein the structure supports the flexible substrate on the support body so that the flexible substrate can swing.

5. A battery module according to any one of claims 1 to 4, wherein the structure slidably supports the flexible substrate on the support.

6. The battery module according to any one of claims 1 to 5, wherein the flexible substrate has a fuse electrically connected to the battery cell.

7. A battery module comprising: a battery cell; a support; and a flexible substrate electrically connected to the battery cell and attached to the support, wherein the flexible substrate is at least partially twisted between a portion of the flexible substrate attached to the support and a portion of the flexible substrate electrically connected to the battery cell.

8. The battery module according to claim 7, wherein the battery cells have tabs, the support has a frame body that at least partially surrounds the tabs, and the flexible substrate and the frame body are attached to each other.

9. The battery module according to claim 7 or 8, wherein the flexible substrate has a fuse electrically connected to the battery cell.

10. A battery module described in any one of claims 7 to 9, wherein the flexible substrate defines a slit between the portion of the flexible substrate attached to the support and the portion of the flexible substrate electrically connected to the battery cell.

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