Voltage detection device and battery module

Abstract

A first voltage detection device (300) is provided with a first holding body (310) and a plurality of first voltage detection lines (330) held by the first holding body (310). A portion, of the first holding body (310), overlapping the plurality of first voltage detection lines (330) that are bundled together has a heat resistance that is higher than the heat resistance of at least another portion of the first holding body (310) different from said portion.

Description

Voltage detection device and battery module

[0001] The present invention relates to a voltage detection device and a battery module.

[0002] In recent years, various battery modules have been developed, and some battery modules include battery cells and voltage detection devices electrically connected to the battery cells.

[0003] Patent Document 1 describes a battery module. The battery module includes a battery cell and a voltage sensing assembly. The voltage sensing assembly includes a block case and a wire fixed to the block case.

[0004] Patent Document 2 describes a wiring module, which includes connection members that connect adjacent electrode terminals of a plurality of energy storage elements together, and an insulating protector that houses the connection members.

[0005] JP 2014-516457 A JP 2015-28858 A

[0006] In a voltage detection device, a plurality of voltage detection wires may be held by a holder. The plurality of voltage detection wires may be at least partially bundled together. Meanwhile, in a battery module, a relatively high-temperature gas may be generated from a battery cell due to an abnormality in the battery cell. In a battery module, it may be necessary to prevent a short circuit between the plurality of bundled voltage detection wires when gas is generated from the battery cell.

[0007] One example of an object of the present invention is to prevent a short circuit between multiple voltage detection wires bundled together when gas is generated from a battery cell. Other objects of the present invention will become apparent from the description of this specification.

[0008] One aspect of the present invention is as follows: 1. A voltage detection device comprising: a holder; and a plurality of voltage detection wires held by the holder, wherein a portion of the holder that overlaps with the bundled voltage detection wires has a higher heat resistance than at least a portion of the holder that is different from the portion. 2. The voltage detection device described in 1., in which the thickness of the portion of the holder is at least partially greater than the thickness of the at least one other portion of the holder. 3. The voltage detection device described in 1., in which the heat resistance of a material that constitutes the portion of the holder is higher than the heat resistance of a material that constitutes the at least one other portion of the holder. 4. A battery module comprising: the voltage detection device described in any one of 1. to 3.; and battery cells electrically connected to the voltage detection wires.

[0009] According to the above aspect of the present invention, it is possible to prevent a short circuit between a plurality of voltage detection wires that are bundled together when gas is generated from a battery cell.

[0010] 2 is an exploded perspective view of a battery module according to an embodiment of the present invention; FIG. 3 is a front view of a first voltage detection device according to an embodiment of the present invention; FIG.

[0011] Hereinafter, embodiments 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 the description thereof will be omitted as appropriate.

[0012] FIG. 1 is an exploded top perspective view of a battery module 10 according to an embodiment.

[0013] For the purpose of explanation, FIG. 1 shows the X, Y, and Z directions. The X direction indicates the front-to-rear direction of the battery module 10. The Y direction is one of the directions perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery module 10. The Z direction is a direction perpendicular to both the X and Y directions. The Z direction indicates the up-down direction of the battery module 10. The arrows pointing to the X direction, the Y direction, and the Z direction indicate the rearward, rightward, and upward directions of the battery module 10, respectively. Hereinafter, as necessary, the tip side of an 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 an 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 an 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 10 is not limited to the above example.

[0014] The battery module 10 includes a plurality of battery cells 100 , a plurality of compression pads 200 , a first voltage detection device 300 , a second voltage detection device 400 , a module housing 500 , a positive bus bar 610 , and a negative bus bar 620 .

[0015] The multiple battery cells 100 and the multiple compression pads 200 are stacked alternately in the Y direction. Each compression pad 200 is disposed between adjacent battery cells 100 in the Y direction. Hereinafter, unless otherwise specified, a stack of battery cells 100 refers to the multiple battery cells 100 and the multiple compression pads 200 stacked alternately in the Y direction. The X-direction dimension of each battery cell 100 is the longitudinal dimension of each battery cell 100. The Z-direction dimension of each battery cell 100 is the lateral dimension of each battery cell 100. The Y-direction dimension of each battery cell 100 is the thickness dimension of each battery cell 100. The shape of each battery cell 100 is not limited to this example.

[0016] Each battery cell 100 includes a battery element (not shown), an exterior material 110, a positive electrode terminal 122, and a negative electrode terminal 124. 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 110 seals the battery element and an electrolyte (not shown). The positive electrode terminal 122 is electrically connected to the positive electrode of the battery element. The positive electrode terminal 122 is drawn out from one of both sides of the exterior material 110 in the X direction. The negative electrode terminal 124 is electrically connected to the negative electrode of the battery element. The negative electrode terminal 124 is drawn out from the other side of both sides of the exterior material 110 in the X direction. However, the structure of each battery cell 100 is not limited to this example.

[0017] Each battery cell 100 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 electrolytic solution. Unless otherwise specified, the following description will be given assuming that each battery cell 100 is a battery cell containing an electrolytic solution.

[0018] The multiple battery cells 100 are electrically connected in a combination of series and parallel. Specifically, cell groups including at least two battery cells 100 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 100, a positive terminal 122 drawn from a battery cell 100 of one cell group connected in parallel and a negative terminal 124 drawn from a battery cell 100 of another cell group connected in parallel are electrically connected to each other, forming a terminal group 120 including the positive terminal 122 and the negative terminal 124. The positive terminal 122 and the negative terminal 124 in the terminal group 120 are joined to each other by a joining method such as laser welding. A terminal group 120 is also located on the +X side of the stack of battery cells 100. Thus, multiple cell groups are connected in series from a cell group located at one end of the stack of battery cells 100 in the Y direction to a cell group located at the other end of the stack of battery cells 100 in the Y direction. Hereinafter, unless otherwise specified, the −X side terminal group 120 refers to the terminal group 120 located on the −X side of the stack of battery cells 100, and the +X side terminal group 120 refers to the terminal group 120 located on the +X side of the stack of battery cells 100.

[0019] The electrical connection of the plurality of battery cells 100 is not limited to the above example. For example, the cell group may include three or more battery cells 100 connected in parallel. Alternatively, a stack of battery cells 100 may be formed by connecting single battery cells 100 in series.

[0020] The first voltage detecting device 300 detects the voltages of the plurality of −X side terminal groups 120. The first voltage detecting device 300 has a first holding body 310, a plurality of first voltage detecting terminals 320, and a first connector 340.

[0021] The first holder 310 covers the -X side portion of the stack of battery cells 100. The first holder 310 is, for example, an insulator such as resin. The first holder 310 defines a plurality of first openings 311. Each of the plurality of -X side terminal groups 120 is exposed toward the -X side through each of the plurality of first openings 311.

[0022] Each of the multiple first voltage detection terminals 320 is located on the -X side of each of the multiple -X side terminal groups 120. Each first voltage detection terminal 320 is, for example, a conductor such as metal. The +X side surface of each first voltage detection terminal 320 and the -X side surface of each -X side terminal group 120 are joined to each other by a joining method such as laser welding. Therefore, each first voltage detection terminal 320 and each -X side terminal group 120 are electrically connected to each other. Therefore, the first voltage detection device 300 can detect the voltage of each -X side terminal group 120 using each first voltage detection terminal 320. The multiple first voltage detection terminals 320 are integrally held by a first holder 310. Therefore, by placing the first holder 310 at an appropriate position relative to the stack of battery cells 100, each of the multiple first voltage detection terminals 320 can be positioned appropriately relative to each of the multiple -X side terminal groups 120.

[0023] The first connector 340 is provided on the first holding body 310. The first voltage detection terminals 320 and the first connector 340 are electrically connected to each other via a plurality of voltage detection lines not shown in Fig. 1. The voltage detection lines are routed between the first voltage detection terminals 320 and the first connector 340 via the first holding body 310.

[0024] The second voltage detecting device 400 detects the voltages of the plurality of +X side terminal groups 120. The second voltage detecting device 400 has a second holding body 410 and a plurality of second voltage detecting terminals 420.

[0025] The second holder 410 covers the +X side portion of the stack of battery cells 100. The second holder 410 is, for example, an insulator such as resin. The second holder 410 defines a plurality of second openings 411. Each of the plurality of +X side terminal groups 120 is exposed toward the +X side through each of the plurality of second openings 411.

[0026] Each of the multiple second voltage detection terminals 420 is located on the +X side of each of the multiple +X side terminal groups 120. Each second voltage detection terminal 420 is, for example, a conductor such as metal. The -X side surface of each second voltage detection terminal 420 and the +X side surface of each +X side terminal group 120 are joined to each other by a joining method such as laser welding. Therefore, each second voltage detection terminal 420 and each +X side terminal group 120 are electrically connected to each other. Therefore, the second voltage detection device 400 can detect the voltage of each +X side terminal group 120 using each second voltage detection terminal 420. The multiple second voltage detection terminals 420 are integrally held by a second holder 410. Therefore, by placing the second holder 410 at an appropriate position relative to the stack of battery cells 100, each of the multiple second voltage detection terminals 420 can be positioned at an appropriate position relative to each of the multiple +X side terminal groups 120.

[0027] Similar to the first voltage detection device 300, the plurality of second voltage detection terminals 420 and a connector not shown in FIG. 1 are electrically connected to each other via a plurality of voltage detection lines not shown in FIG. 1.

[0028] The module housing 500 includes a first plate 510, a second plate 520, a third plate 530, a fourth plate 540, a fifth plate 550, and a sixth plate 560. Each plate is, for example, a conductor such as a metal.

[0029] The first plate 510 covers the -X side portion of the stack of battery cells 100 with the first voltage detection device 300 positioned between the stack of battery cells 100 and the first plate 510. The second plate 520 covers the +X side portion of the stack of battery cells 100 with the second voltage detection device 400 positioned between the stack of battery cells 100 and the second plate 520. The third plate 530 covers the -Y side portion of the stack of battery cells 100 with the first insulating cover 532 positioned between the stack of battery cells 100 and the third plate 530. The first insulating cover 532 can electrically insulate the battery cell 100 located at one end on the -Y side from the third plate 530. The first insulating cover 532 is made of, for example, silica aerogel. The fourth plate 540 covers the +Y side portion of the stack of battery cells 100, with the second insulating cover 542 positioned between the stack of battery cells 100 and the fourth plate 540. The second insulating cover 542 electrically insulates the battery cell 100 located at the other end of the +Y side from the fourth plate 540. The second insulating cover 542 is made of, for example, silica aerogel. The fifth plate 550 covers the -Z side portion of the stack of battery cells 100, with the thermally conductive adhesive 552 positioned between the stack of battery cells 100 and the fifth plate 550. The thermally conductive adhesive 552 allows heat generated from the stack of battery cells 100 to dissipate toward the fifth plate 550. The sixth plate 560 covers the +Z side portion of the stack of battery cells 100.

[0030] The positive electrode bus bar 610 is located at the end of the first holder 310 on the -Y side. The positive electrode bus bar 610 and the -X side positive electrode terminal 122 of the cell group including the plurality of battery cells 100 located at one end on the -Y side are joined to each other by a joining method such as laser welding. Therefore, the positive electrode bus bar 610 and the cell group located at one end on the -Y side are electrically connected to each other. The positive electrode bus bar 610 functions as an external terminal for electrically connecting the battery module 10 to an external device such as another battery module.

[0031] The negative electrode bus bar 620 is located at the end of the first holder 310 on the +Y side. The negative electrode bus bar 620 and the negative electrode terminal 124 on the −X side of the cell group including the plurality of battery cells 100 located at the other end on the +Y side are joined to each other by a joining method such as laser welding. Therefore, the negative electrode bus bar 620 and the cell group located at the other end on the +Y side are electrically connected to each other. The negative electrode bus bar 620 functions as an external terminal for electrically connecting the battery module 10 to an external device such as another battery module.

[0032] 1 , the positive electrode terminal 122 at the end of a group of multiple cells connected in series is the positive electrode terminal 122 on the −X side of the cell group located at one end on the −Y side, and the negative electrode terminal 124 at the end of a group of multiple cells connected in series is the negative electrode terminal 124 on the −X side of the cell group located at the other end on the +Y side. Thus, the positive electrode bus bar 610 is disposed on the −X side and the −Y side of the stack of battery cells 100, and the negative electrode bus bar 620 is disposed on the −X side and the +Y side of the stack of battery cells 100. However, the arrangement of the positive electrode terminal 122 and the negative electrode terminal 124 at the end of a group of multiple cells connected in series may differ depending on the number of cell groups included in the stack of battery cells 100. For example, there are cases where the positive electrode terminal 122 at the end of a group of multiple cells connected in series is the positive electrode terminal 122 on the −X side of the cell group located at one end on the −Y side, and the negative electrode terminal 124 at the end of a group of multiple cells connected in series is the negative electrode terminal 124 on the +X side of the cell group located at the other end on the +Y side. In this case, the positive electrode bus bar 610 is arranged on the −X side and the −Y side of the stack of battery cells 100, and the negative electrode bus bar 620 is arranged on the +X side and the +Y side of the stack of battery cells 100.

[0033] 2 is a front view of the first voltage detection device 300 according to the embodiment. In FIG. 2, the white circle with an X indicating the X direction indicates that the arrow indicating the X direction extends from the front to the back of the page. The matters described below regarding the first voltage detection device 300 using FIG. 2 are also applicable to the second voltage detection device 400.

[0034] The first holding body 310 according to the embodiment has a wiring portion 310a and a collecting portion 310b. The first holding body 310, including the wiring portion 310a and the collecting portion 310b, is made of an insulating material such as resin. The first voltage detection device 300 according to the embodiment has a plurality of first voltage detection wires 330. The plurality of first voltage detection wires 330 are electrically connected to a plurality of first voltage detection terminals 320 and a first connector 340.

[0035] The routing section 310a routes the plurality of first voltage detection wires 330 individually. The routing section 310a defines a plurality of first openings 311. Each of the first voltage detection wires 330 individually routed in the routing section 310a is drawn out from each first voltage detection terminal 320 toward the +Z side and extends at least partially in the Z direction. The routing section 310a and the first voltage detection wires 330 individually routed in the routing section 310a at least partially overlap each other in the Z direction, with the routing section 310a being at least partially positioned between the plurality of battery cells 100 and the plurality of first voltage detection wires 330.

[0036] The collecting portion 310b bundles the multiple first voltage detection wires 330 together. The first connector 340 is located approximately in the center of the collecting portion 310b in the Y direction. The multiple first voltage detection wires 330 bundled together in the collecting portion 310b are drawn out toward the first connector 340 and extend at least partially in the Y direction. The collecting portion 310b and the multiple first voltage detection wires 330 bundled together in the collecting portion 310b at least partially overlap each other in the Z direction, with the collecting portion 310b at least partially positioned between the multiple battery cells 100 and the multiple first voltage detection wires 330.

[0037] In the embodiment, the collecting portion 310b has a higher heat resistance than at least one other portion of the first holder 310 that is different from the collecting portion 310b. The at least one other portion of the first holder 310 is, for example, the routing portion 310a. Abnormalities in the battery cells 100 can generate relatively high-temperature gas from the battery cells 100. In the embodiment, melting of the collecting portion 310b due to gas generated from the battery cells 100 being blown onto the collecting portion 310b can be suppressed compared to when the heat resistance of the entire first holder 310, including the heat resistance of the collecting portion 310b, is relatively low. If gas is blown directly onto the multiple first voltage detection wires 330 bundled together, there is a possibility that the multiple first voltage detection wires 330 will be short-circuited to each other due to factors such as melting of the insulating coating of the first voltage detection wires 330. However, in the embodiment, by suppressing melting of the collecting portion 310b due to gas generated from the battery cells 100, it is possible to suppress short-circuiting between the bundled first voltage detection wires 330 in a state in which gas is generated from the battery cells 100. Furthermore, in the embodiment, the heat resistance of at least another portion of the first holding body 310 different from the collecting portion 310b can be made relatively low, and the cost of the first holding body 310 can be reduced, compared to when the heat resistance of the entire first holding body 310 is relatively high, including the heat resistance of at least another portion of the first holding body 310 different from the collecting portion 310b.

[0038] The heat resistance of the collecting portion 310b can be adjusted by the X-direction thickness of a substantially plate-shaped portion of the collecting portion 310b perpendicular to the X-direction. In one example, the X-direction thickness of the substantially plate-shaped portion of the collecting portion 310b perpendicular to the X-direction is at least partially thicker than the X-direction thickness of at least another portion of the first holding body 310 that is different from the collecting portion 310b. In this example, the heat resistance of the collecting portion 310b can be higher than the heat resistance of at least another portion of the first holding body 310 that is different from the collecting portion 310b. In this example, the material constituting the first holding body 310 may be the same regardless of the position on the first holding body 310.

[0039] The heat resistance of the aggregating portion 310b can be adjusted by the material constituting the aggregating portion 310b. In one example, the heat resistance of the material constituting the aggregating portion 310b is higher than the heat resistance of the material constituting at least a portion of the first holding body 310 that is different from the aggregating portion 310b. In this example, the material constituting the aggregating portion 310b can be polybutylene terephthalate (PBT), and the material constituting at least a portion of the first holding body 310 that is different from the aggregating portion 310b can be polypropylene (PP). In this example, the heat resistance of the aggregating portion 310b can be higher than the heat resistance of at least a portion of the first holding body 310 that is different from the aggregating portion 310b. In this example, the thickness in the X direction of the approximately plate-shaped portion of the first holding body 310 perpendicular to the X direction may be constant regardless of the position on the first holding body 310.

[0040] To improve the heat resistance of the collecting portion 310b, the thickness in the X direction of the substantially plate-shaped portion of the collecting portion 310b perpendicular to the X direction can be, for example, 3.0 mm or more if the material of the collecting portion 310b is PP, and can be, for example, 2.0 mm or more if the material of the collecting portion 310b is PBT. The upper limit of the thickness in the X direction of the substantially plate-shaped portion of the collecting portion 310b perpendicular to the X direction is not particularly limited, but can be, for example, 5.0 mm.

[0041] In the embodiment, the routing portion 310a has lower heat resistance than at least one other portion of the first holder 310 that is different from the routing portion 310a. The at least one other portion of the first holder 310 is, for example, the collecting portion 310b. In the embodiment, compared to when the entire first holder 310 has a relatively high heat resistance, including the routing portion 310a, the routing portion 310a can be more easily melted by gas generated from the battery cells 100 being blown onto the routing portion 310a. If the routing portion 310a melts, the impact of the gas generated from the battery cells 100 can break the individually routed first voltage detection wire 330. Therefore, when gas is generated from the battery cells 100, the circuit including the first voltage detection wire 330 can be interrupted. Therefore, compared to when the circuit including the first voltage detection wire 330 is not interrupted, an overcurrent can be less likely to flow through the circuit including the first voltage detection wire 330.

[0042] The heat resistance of the wiring part 310a can be adjusted by the X-direction thickness of a substantially plate-shaped portion of the wiring part 310a perpendicular to the X-direction. In one example, the X-direction thickness of the substantially plate-shaped portion of the wiring part 310a perpendicular to the X-direction is at least partially thinner than the X-direction thickness of at least a portion of the substantially plate-shaped portion of the first holding body 310 that is different from the wiring part 310a. In this example, the heat resistance of the wiring part 310a can be lower than the heat resistance of at least a portion of the first holding body 310 that is different from the wiring part 310a. In this example, the material constituting the first holding body 310 may be the same regardless of the position on the first holding body 310.

[0043] The heat resistance of the wiring part 310a can be adjusted by the material constituting the wiring part 310a. In one example, the heat resistance of the material constituting the wiring part 310a is lower than the heat resistance of the material constituting at least a portion of the first holding body 310 that is different from the wiring part 310a. In this example, the material constituting the wiring part 310a can be PP, and the material constituting the at least a portion of the first holding body 310 that is different from the wiring part 310a can be PBT. In this example, the heat resistance of the wiring part 310a can be lower than the heat resistance of at least a portion of the first holding body 310 that is different from the wiring part 310a. In this example, the thickness in the X direction of the approximately plate-shaped portion of the first holding body 310 perpendicular to the X direction may be constant regardless of the position on the first holding body 310.

[0044] From the viewpoint of making it easier for the wiring part 310a to melt due to the gas generated from the battery cell 100, the thickness in the X direction of the substantially plate-shaped part of the wiring part 310a perpendicular to the X direction can be set to, for example, 1.5 mm or less when the material constituting the wiring part 310a is PP. The lower limit of the thickness in the X direction of the substantially plate-shaped part of the wiring part 310a perpendicular to the X direction is not particularly limited, but can be set to, for example, 1.0 mm.

[0045] To make the first voltage detection wire 330 more susceptible to disconnection by gas generated from the battery cell 100, the first voltage detection wire 330 may at least partially include a flexible printed circuit (FPC). The FPC includes, for example, a flexible member such as polyimide and a conductor such as copper foil held by the flexible member. When gas generated from the battery cell 100 is blown onto the FPC, the flexible member melts due to the temperature of the gas, and the conductor is disconnected by the impact of the gas jet. The entire first voltage detection wire 330 may be an FPC. Alternatively, only the routed portion of the routed portion 310a of the first voltage detection wire 330 may be an FPC. The first voltage detection wire 330 may include, for example, a harness instead of or in addition to an FPC.

[0046] Figure 3 shows a modification of Figure 2. The modification shown in Figure 3 is similar to the embodiment shown in Figure 2, except for the following points.

[0047] In the example shown in Fig. 3 , the wiring portion 310a is at least partially cut out by a notch 311a. The notch 311a and the first voltage detection line 330 at least partially overlap in the X direction. Therefore, gas generated from the battery cell 100 passes through the notch 311a and is sprayed onto the portion of the first voltage detection line 330 that overlaps with the notch 311a in the X direction. Therefore, the impact of the spray of gas generated from the battery cell 100 can break the first voltage detection line 330 in the wiring portion 310a. Therefore, when gas is generated from the battery cell 100, the circuit including the first voltage detection line 330 can be interrupted.

[0048] Instead of or in addition to the notch 311a, the routing portion 310a may be at least partially cut out by a hole penetrating the routing portion 310a in the X direction. The hole in the routing portion 310a and the first voltage detection line 330 at least partially overlap in the X direction. Even when the routing portion 310a defines a hole, gas generated from the battery cell 100 passes through the hole in the routing portion 310a and is sprayed onto the portion of the first voltage detection line 330 that overlaps with the hole in the X direction. Therefore, the impact of the gas sprayed from the battery cell 100 can break the first voltage detection line 330 in the routing portion 310a. Therefore, when gas is generated from the battery cell 100, the circuit including the first voltage detection line 330 can be interrupted.

[0049] Although the embodiments 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.

[0050] This application claims priority based on Japanese Patent Application No. 2024-028320, filed February 28, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0051] REFERENCE SIGNS LIST 10 Battery module, 100 Battery cell, 110 Exterior material, 120 Terminal group, 122 Positive electrode terminal, 124 Negative electrode terminal, 200 Compression pad, 300 First voltage detection device, 310 First holder, 310a Wiring section, 310b Aggregation section, 311 First opening, 311a Notch, 320 First voltage detection terminal, 330 First voltage detection line, 340 First connector, 400 Second voltage detection device, 410 Second holder, 411 Second opening, 420 Second voltage detection terminal, 500 Module housing, 510 First plate, 520 Second plate, 530 Third plate, 532 First insulating cover, 540 Fourth plate, 542 Second insulating cover, 550 Fifth plate, 552 Thermally conductive adhesive, 560 Sixth plate, 610 Positive bus bar, 620 negative bus bar

Claims

1. A voltage detection device comprising: a holder; and a plurality of voltage detection wires held by the holder, wherein a portion of the holder that overlaps with the plurality of voltage detection wires bundled together has higher heat resistance than the heat resistance of at least another portion of the holder that is different from the overlapping portion.

2. A voltage detection device according to claim 1, wherein the thickness of said portion of said holder is at least partially greater than the thickness of said at least one other portion of said holder.

3. A voltage detection device according to claim 1, wherein the heat resistance of the material constituting said portion of said holder is higher than the heat resistance of the material constituting said at least one other portion of said holder.

4. A battery module comprising: a voltage detection device according to any one of claims 1 to 3; and a battery cell electrically connected to the voltage detection line.

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