Temperature detection device and battery module

Abstract

A temperature detection device (24) is provided for detecting the temperature of a battery cell (10). The temperature detection device (24) comprises: a temperature detection element (242); and an elastic body (243) configured to bias the temperature detection element (242) toward the battery cell (10). The elastic body (243) is positioned at least partially on the periphery of the temperature detection element (242).

Description

Temperature detection device and battery module

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

[0002] In recent years, various battery modules have been developed. A battery module may comprise a battery cell and a temperature detection device for detecting the temperature of the battery cell.

[0003] Patent Document 1 describes a mounting device for mounting a temperature sensor in a mounting hole provided in a mounting wall of a member to be mounted. The mounting device comprises a clip body mounted to the mounting hole, and an elastic seal member disposed between the clip body and the mounting wall.

[0004] Patent Document 2 describes a temperature sensor. The temperature sensor comprises a metal plate formed with a U-shaped notch, an elastic body closing the U-shaped notch, and a thermosensitive element placed at a substantially central portion of the elastic body.

[0005] Patent Document 3 describes a thermistor temperature sensor. The thermistor temperature sensor comprises a thermistor element, a covered lead wire electrically connected to the thermistor element, and an elastic body covering a connection portion between the thermistor element and the covered lead wire.

[0006] JP 2010-54270 AJP 7-286911 AJP 11-351975 A

[0007] In a temperature detection device for detecting the temperature of a battery cell, the temperature detection element may be biased against the battery cell by an elastic body. However, when the temperature detection element is biased by the elastic body in a state where the temperature detection element and the elastic body overlap each other, it may become difficult to suppress an increase in the thickness of the temperature detection device, or it may become difficult to suppress the compressed elastic body from crushing the temperature detection element.

[0008] An example of the object of the present invention is to reduce the thickness of a temperature detection device and suppress crushing of a temperature detection element by an elastic body. Other objects of the present invention will become apparent from the description of the present specification.

[0009] One aspect of the present invention is as follows: 1. A temperature detection device for detecting the temperature of a battery cell, comprising: a temperature detection element; and an elastic body configured to bias the temperature detection element to the battery cell, wherein the elastic body is at least partially located around the temperature detection element. 2. The temperature detection device according to 1, further comprising a support for supporting the elastic body, wherein the temperature detection element is at least partially located inside a hole or recess provided in the support. 3. The temperature detection device according to 2, wherein the elastic body is at least partially located inside a hole or recess provided in the support. 4. The temperature detection device according to 1, further comprising a support for supporting the elastic body, wherein the elastic body is located on the side of the support opposite to the side where the battery cell is located, the temperature detection element is at least partially located inside a hole penetrating the support, the hole has an opening located on the side of the support, and the side of the temperature detection element opposite to the side where the battery cell is located is located on the side where the battery cell is located, A temperature detection device as described in [reference]. 5. A battery module comprising a battery cell and a temperature detection device as described in any one of [references] 1 to 4, which detects the temperature of the battery cell using the temperature detection element.

[0010] According to the above embodiment of the present invention, the thickness of the temperature detection device can be reduced, and crushing of the temperature detection element by an elastic body can be suppressed.

[0011] This is an exploded perspective view of a portion of a battery module according to an embodiment. The figure shows a temperature detection device pressed against the battery cell by a pressing body in a cross-section along the line A-A in Figure 1.

[0012] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate.

[0013] Figure 1 is an exploded perspective view of a portion of the battery module 1 according to an embodiment.

[0014] Figure 1 shows the X-axis, Y-axis, and Z-axis for illustrative purposes, indicating the X, Y, and Z directions, respectively. The X-axis indicates the front-to-back direction of the battery module 1. The Y-axis is one of the directions perpendicular to the X-axis and indicates the left-to-right direction of the battery module 1. The Z-axis is perpendicular to both the X and Y directions and indicates the up-to-down direction of the battery module 1. Hereafter, unless otherwise specified, the directions indicated by the arrows on the X-axis, Y-axis, and Z-axis refer to the rear, right, and up directions of the battery module 1, respectively. The front-to-back, left-to-right, and up-to-down directions of the battery module 1 are not limited to the examples given above.

[0015] Unless otherwise specified, the +X side or +X refers to the side indicated by the arrow on the X axis, and the -X side or -X refers to the opposite side of the side indicated by the arrow on the X axis. Unless otherwise specified, the +Y side or +Y refers to the side indicated by the arrow on the Y axis, and the -Y side or -Y refers to the opposite side of the side indicated by the arrow on the Y axis. Unless otherwise specified, the +Z side or +Z refers to the side indicated by the arrow on the Z axis, and the -Z side or -Z refers to the opposite side of the side indicated by the arrow on the Z axis.

[0016] Referring to Figure 1, the battery module 1 according to the embodiment will be described. The battery module 1 according to the embodiment includes a plurality of battery cells 10, a voltage detection device 20, and a busbar 30.

[0017] Multiple battery cells 10 are stacked in the Y direction. Each battery cell 10 has an outer casing 11, a positive terminal 12, and a negative terminal 13.

[0018] The outer casing 11 seals a battery element (not shown) and an electrolyte. In one example, the battery element includes a plurality of positive electrodes and a plurality of negative electrodes stacked alternately in the Y direction, and a separator located between adjacent positive and negative electrodes in the Y direction. The positive and negative electrodes may be wound around a winding shaft extending in a predetermined direction. Each battery cell 10 may be an all-solid-state battery that does not use an electrolyte. The portion of the outer casing 11 that seals the battery element has a substantially rectangular parallelepiped shape with a pair of faces substantially perpendicular to the X direction, a pair of faces substantially parallel to the Y direction, and a pair of faces substantially parallel to the Z direction. The dimensions of each side of this portion of the outer casing 11 are in the order of the sides substantially parallel to the Y direction, the sides substantially parallel to the Z direction, and the sides substantially parallel to the X direction being the longest. The shape of each battery cell 10 is not limited to the example shown in Figure 1.

[0019] The positive terminal 12 is electrically connected to the positive electrode of the battery element, and the negative terminal 13 is electrically connected to the negative electrode of the battery element. In some embodiments, the positive terminal 12 is formed of at least one of aluminum and an aluminum alloy. In some embodiments, the negative terminal 13 is formed of at least one of copper and a copper alloy. The materials used to form the positive terminal 12 and the negative terminal 13 are not limited to those described above. The positive terminal 12 is drawn out from one of the +X side and -X side of the housing material 11, and the negative terminal 13 is drawn out from the other of the +X side and -X side of the housing material 11.

[0020] In the battery module 1, multiple battery cells 10 connected in parallel are connected in series. Hereafter, unless otherwise specified, "parallel battery cell 10" refers to battery cells 10 connected in parallel. In the example shown in Figure 1, the parallel battery cell 10 includes two battery cells 10 adjacent to each other in the Y direction. The two battery cells 10 included in the parallel battery cell 10 are connected in parallel by the positive terminals 12 located on one of the +X and -X sides of the two battery cells 10 being electrically connected to each other, and the negative terminals 13 located on the other of the +X and -X sides of the two battery cells 10 being electrically connected to each other. Two parallel battery cells 10 adjacent to each other in the Y direction are connected in series by the positive terminal 12 located on one of the +X and -X sides of one of the parallel battery cells 10 and the negative terminal 13 located on one of the +X and -X sides of the other parallel battery cell 10 being electrically connected to each other. Unless otherwise specified, the terminal group 14 refers to the positive terminal 12 located on one of the +X and -X sides of one of two parallel battery cells 10 adjacent in the Y direction, and the negative terminal 13 located on one of the +X and -X sides of the other parallel battery cell 10 adjacent in the Y direction. The positive terminal 12 and negative terminal 13 included in the terminal group 14 are electrically connected to each other. Multiple parallel battery cells 10 are connected in series via multiple terminal groups 14 that are alternately located in the X direction, from the parallel battery cell 10 located at one end of the multiple battery cells 10 in the Y direction to the parallel battery cell 10 located at the other end of the multiple battery cells 10 in the Y direction.

[0021] The electrical connections of the multiple battery cells 10 are not limited to the examples of the embodiment. For example, the parallel battery cells 10 may include three or more battery cells 10 connected in parallel. Alternatively, instead of multiple parallel battery cells 10, multiple single battery cells 10 may be connected in series.

[0022] The voltage detection device 20 includes a protector 21, a flexible substrate 22, a plurality of voltage detection terminals 23, and a plurality of temperature detection devices 24.

[0023] The protector 21 is positioned on the -X side portion of the plurality of battery cells 10. The protector 21 has electrical insulating properties and is made of a resin such as PBT (polybutylene terephthalate). The protector 21 defines a plurality of openings 211 that expose a plurality of +X side terminal groups 14. The protector 21 covers substantially the entire +X side portion of the plurality of battery cells 10, except for the portion that overlaps with the plurality of openings 211 of the plurality of battery cells 10 in the X direction.

[0024] The flexible substrate 22 is, for example, a flexible printed circuit board (FPC). The flexible substrate 22 is provided on the -X side of the protector 21. In the example shown in Figure 1, the flexible substrate 22 is arranged around a plurality of openings 211. A plurality of bosses 212 are provided on the -X side of the protector 21. The plurality of bosses 212 penetrate the flexible substrate 22. The protector 21 and the flexible substrate 22 are fixed to each other by heat crimping the -X side tips of the plurality of bosses 212 while they are penetrating the flexible substrate 22. Heat crimping the -X side tips of the bosses 212 prevents the flexible substrate 22 from detaching from the protector 21. Because the protector 21 and the flexible substrate 22 are fixed to each other, the flexible substrate 22 is supported by the protector 21. The method of fixing the protector 21 and the flexible substrate 22 is not limited to the method described above.

[0025] Each voltage detection terminal 23 has a substantially plate shape that is substantially perpendicular to the X direction. Viewed from the X direction, each voltage detection terminal 23 has a substantially rectangular shape with a pair of short sides substantially parallel to the Y direction and a pair of long sides substantially parallel to the Z direction. The shape of each voltage detection terminal 23 is not limited to the example shown in Figure 1. The -X faces of each terminal group 14 on the -X side and the +X faces of each voltage detection terminal 23 are joined to each other, for example, by laser welding. Therefore, each terminal group 14 on the -X side and each voltage detection terminal 23 are electrically connected to each other.

[0026] In the example shown in Figure 1, the multiple temperature detection devices 24 include two temperature detection devices 24 provided on the +Z side of the protector 21 and two temperature detection devices 24 provided on the -Z side of the protector 21. The temperature detection device 24 provided on the +Z side of the protector 21, approximately in the center in the Y direction, is provided to detect the temperature of the +Z side portion of the -X side end of the battery cell 10 located approximately in the center in the Y direction. The temperature detection device 24 provided on the +Z side of the protector 21, at the -Y side end, is provided to detect the temperature of the +Z side portion of the -X side end of the battery cell 10 located at the -Y side end. The temperature detection device 24 provided on the -Z side of the protector 21, approximately in the center in the Y direction, is provided to detect the temperature of the -Z side portion of the -X side end of the battery cell 10 located approximately in the center in the Y direction. The temperature detection device 24 provided at the -Y end on the -Z side of the protector 21 is provided to detect the temperature of the -Z portion of the -X end of the battery cell 10 located at the -Y end. The two temperature detection devices 24 provided on the +Z side of the protector 21 can be substantially identical. The two temperature detection devices 24 provided on the -Z side of the protector 21 can be substantially identical. The two temperature detection devices 24 provided at the approximate center of the protector 21 in the Y direction are arranged substantially symmetrically with respect to a plane passing through the approximate center of the protector 21 in the Z direction in a direction perpendicular to the Z direction. The two temperature detection devices 24 provided at the -Y end of the protector 21 are arranged substantially symmetrically with respect to a plane passing through the approximate center of the protector 21 in the Z direction in a direction perpendicular to the Z direction. The number and position of the temperature detection devices 24 are not limited to the example shown in Figure 1, and can be appropriately determined according to the number of battery cells 10 to be measured and the measurement position of the battery cells 10.

[0027] The busbar 30 is located at the -Y end of the protector 21. The busbar 30 is electrically connected to the positive terminal 12 that is drawn out to the -X side from the parallel battery cell 10 located at the -Y end.

[0028] In the example shown in Figure 1, a voltage detection device 20 located on the -X side relative to a plurality of battery cells 10 is illustrated. In this embodiment, a voltage detection device, not shown in Figure 1, is also located on the +X side relative to the plurality of battery cells 10. In one example, the voltage detection device located on the +X side relative to the plurality of battery cells 10 can be substantially the same as the voltage detection device 20 shown in Figure 1.

[0029] Figure 2 shows a temperature detection device 24 pressed against the battery cell 10 by the pressing body 40 in a cross-section along the line A-A in Figure 1. In Figure 2, the white circle with a black dot indicating the Y-axis indicates that the Y-axis arrow is pointing towards the viewer on the page.

[0030] Referring to Figure 2, the temperature detection device 24 located on the -Y side of the protector 21 on the +Z side in Figure 1 will be described. Refer to Figure 1 as needed. The matters described with reference to Figure 2 are also applicable to other temperature detection devices 24.

[0031] As shown in Figures 1 and 2, the temperature detection device 24 includes a support 241, a temperature detection element 242, two elastic bodies 243, and a reinforcing frame 244. In the example shown in Figure 2, the temperature detection device 24 is pressed against the battery cell 10 by a pressing body 40 located on the +Z side relative to the temperature detection device 24. The pressing body 40 is, for example, a plate that forms a housing for a plurality of battery cells 10 and a voltage detection device 20 and covers the +Z side portion of the plurality of battery cells 10. In Figure 1, the pressing body 40 is omitted. In Figure 2, the battery cell 10 is omitted.

[0032] Viewed from the +Z side, the support 241 has a substantially rectangular shape with a pair of long sides substantially parallel to the X direction and a pair of short sides substantially parallel to the Y direction. The support 241 is made of, for example, resin. As shown in Figure 1, the support 241 of the temperature detection device 24 located on the -Y side on the +Z side of the protector 21 protrudes from the +Z side portion of the protector 21 toward the +X side. In the example shown in Figure 2, the support 241 is positioned substantially perpendicular to the Z direction when the temperature detection device 24 is pressed against the battery cell 10 by the pressing body 40. The shape of the support 241 is not limited to the examples shown in Figures 1 and 2.

[0033] In this embodiment, the temperature detection element 242 is a thermistor. The temperature detection element 242 is not limited to a thermistor, as long as it is an element capable of detecting the temperature of the battery cell 10. As shown in Figure 2, the temperature detection element 242 is at least partially located inside a hole 241a that penetrates the approximate center of the support 241 in the Z direction. Therefore, the thickness of the temperature detection device 24 in the Z direction can be suppressed compared to the case where the temperature detection element 242 is provided on the +Z side of the support 241 when the hole 241a is not provided in the support 241. The temperature detection element 242 may also be at least partially located inside a recess provided on the -Z side of the support 241. This recess is open on the -Z side and does not penetrate the support 241 in the Z direction. Alternatively, the temperature detection element 242 may be located on the +Z side of the support 241 when neither a hole nor a recess is provided in the support 241.

[0034] As shown in Figure 2, a portion of the flexible substrate 22 is located on the -Z side of the support 241. The +X side end of the flexible substrate 22 closes the -Z side opening of the hole 241a. The temperature detection element 242 and the +Z side of the +X side end of the flexible substrate 22 are electrically connected to each other by conductivity such as soldering. In the example shown in Figure 2, the +X side end of the flexible substrate 22 also functions as a support to prevent the temperature detection element 242 from falling from the hole 241a to the -Z side. In the example shown in Figure 2, the temperature detection element 242 detects the temperature of the battery cell 10 in close proximity to the battery cell 10 with the +X side end of the flexible substrate 22 positioned between the battery cell 10 and the temperature detection element 242. The temperature detection element 242 may also detect the temperature of the battery cell 10 by directly contacting it.

[0035] In the example shown in Figure 2, the +Z plane of the temperature detection element 242 is located on the -Z side of the +Z opening of the hole 241a. When the +Z plane of the temperature detection element 242 is located on the -Z side of the +Z opening of the hole 241a, the +Z plane of the temperature detection element 242 and the -Z plane of the pressing body 40 are less likely to come into contact compared to when the +Z plane of the temperature detection element 242 is located on the +Z side of the +Z opening of the hole 241a. Therefore, the temperature of the battery cell 10 can be more accurately detected by the temperature detection element 242 compared to when the +Z plane of the temperature detection element 242 and the -Z plane of the pressing body 40 are in contact.

[0036] The two elastic bodies 243 are configured to bias the temperature sensing element 242 to the battery cell 10. Each elastic body 243 is, for example, a sponge or rubber. In the example shown in Figure 2, the two elastic bodies 243 are at least partially located inside two recesses 241b provided on both sides of the hole 241a in the support 241 in the X direction. Each recess 241b opens to the +Z side. The thickness of the support 241 in the Z direction is partially reduced by the recesses 241b. The support 241 supports the two elastic bodies 243 by at least partially fitting inside the recesses 241b. By at least partially fitting the elastic bodies 243 into the recesses 241b, the thickness of the temperature sensing device 24 in the Z direction can be reduced compared to the case where the elastic bodies 243 are provided on the +Z side of the support 241 without the recesses 241b being provided in the support 241. The elastic body 243 may be located inside a hole provided in the support 241. Alternatively, the elastic body 243 may be located on the +Z side of the support 241 where neither a hole nor a recess is provided.

[0037] When the temperature detection device 24 is pressed against the battery cell 10 by the pressing body 40, each elastic body 243 is compressed in the Z direction by the support body 241 and the pressing body 40. The compression of each elastic body 243 in the Z direction biases the support body 241 and the temperature detection element 242 against the battery cell 10. Therefore, compared to the case where the support body 241 and the temperature detection element 242 are not biased, the battery cell 10 and the temperature detection element 242 can be reliably pressed against each other with the flexible substrate 22 positioned between the battery cell 10 and the temperature detection element 242. In the example shown in Figure 2, the +Z surface of each elastic body 243 protrudes to the +Z side from the +Z side opening of the recess 241b. Therefore, compared to the case where the +Z surface of the elastic body 243 is located to the -Z side from the +Z side opening of the recess 241b, it is possible to compress the elastic body 243 in the Z direction by the -Z surface of the pressing body 40.

[0038] The two elastic bodies 243 are located on either side of the temperature sensing element 242 in the X direction. Therefore, when viewed from the +Z side, the two elastic bodies 243 are at least partially located around the temperature sensing element 242. Consequently, the temperature sensing element 242 and the elastic bodies 243 do not overlap each other in the Z direction. Thus, the thickness of the temperature detection device 24 in the Z direction can be reduced compared to the case where the temperature sensing element 242 and the elastic bodies 243 overlap each other in the Z direction. Furthermore, if the temperature detection device 24 were pressed against the battery cell 10 by the pressing body 40 while the temperature sensing element 242 and the elastic bodies 243 were overlapping each other in the Z direction, the elastic bodies 243, which are compressed in the Z direction and become substantially rigid, could crush the temperature sensing element 242. In the example shown in Figure 2, even if the elastic bodies 243 become substantially rigid when compressed in the Z direction, crushing of the temperature sensing element 242 by the elastic bodies 243 can be suppressed. The elastic body 243 may be located at least partially inside a hole penetrating the support 241, instead of in a recess provided on the +Z plane of the support 241.

[0039] The positions of the temperature sensing element 242 and the elastic body 243 are not limited to the examples shown in Figures 1 and 2, as long as the temperature sensing element 242 and the elastic body 243 do not overlap each other in the Z direction. For example, the elastic body 243 may be located only on either the +X side or the -X side of the temperature sensing element 242. Alternatively, when viewed from the +Z side, the elastic body 243 may have a frame shape surrounding the temperature sensing element 242.

[0040] In the examples shown in Figures 1 and 2, a reinforcing frame 244 is provided around the temperature sensing element 242 in the hole 241a. The reinforcing frame 244 is made of a material harder than the material constituting the support 241. Therefore, the strength of the support 241 can be reinforced by the reinforcing frame 244. Thus, compared to the case where the reinforcing frame 244 is not provided, the portion of the support 241 around the hole 241a can withstand a stronger pressing force from the pressing body 40. The reinforcing body corresponding to the reinforcing frame 244 does not have to be located around the entire area of ​​the temperature sensing element 242, but may be located at least partially around the temperature sensing element 242.

[0041] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted.

[0042] This application claims priority based on Japanese Patent Application No. 2025-051848, filed on 26 March 2025, and incorporates all of its disclosures herein.

[0043] 1 Battery module, 10 Battery cell, 11 Outer casing, 12 Positive terminal, 13 Negative terminal, 14 Terminal group, 20 Voltage detection device, 21 Protector, 211 Opening, 212 Boss, 22 Flexible substrate, 23 Voltage detection terminal, 24 Temperature detection device, 241 Support, 241a Hole, 241b Recess, 242 Temperature detection element, 243 Elastic body, 244 Reinforcement frame, 30 Busbar, 40 Pressing body

Claims

1. A temperature detection device for detecting the temperature of a battery cell, comprising: a temperature detection element; and an elastic body configured to bias the temperature detection element toward the battery cell, wherein the elastic body is at least partially located around the temperature detection element.

2. The temperature detection device according to claim 1, further comprising a support for the elastic body, wherein the temperature detection element is at least partially located inside a hole or recess provided in the support.

3. The temperature detection device according to claim 2, wherein the elastic body is at least partially located inside a hole or recess provided in the support.

4. The temperature detection device according to claim 1, further comprising a support for the elastic body, wherein the elastic body is located on the side of the support opposite to the side in which the battery cell is located, the temperature detection element is located at least partially inside a hole penetrating the support, the hole has an opening located on the side of the support, and the side of the temperature detection element opposite to the side in which the battery cell is located is located on the side in which the battery cell is located, beyond the opening of the hole.

5. A battery module comprising: a battery cell; and a temperature detection device according to any one of claims 1 to 4, which detects the temperature of the battery cell using the temperature detection element.

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