Battery module

Abstract

A battery module (1) is provided with: a battery cell (100); a fuse (233) electrically connected to the battery cells (100) and extending in a given direction; and a surrounding heat-resistant body (211) and a covering heat-resistant body (311) that at least partially surround the fuse (233) around the given direction.

Description

Technical Field

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

[0002] In recent years, various battery modules have been developed. For example, as described in Patent Document 1, a battery module includes multiple battery cells stacked in a predetermined direction and bus bars electrically connecting the multiple battery cells. In the battery module described in Patent Document 1, the bus bars have fuses. The battery module also includes an insulating cover surrounding the bus bars and a module cover secured to the upper portion of the insulating cover.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2019 / 069837 Summary of the Invention

[0006] -Problems to be solved by the invention-

[0007] For example, as described in Patent Document 1, a fuse is sometimes electrically connected to a battery cell. If the fuse melts, it not only falls downward but also sometimes scatters around the fuse. However, if the fuse scatters around the fuse, it can be difficult to prevent the impact on components surrounding the fuse.

[0008] One example of the purpose of the present invention is to suppress the influence of the scattering of the fuse on the components around the fuse. Other purposes of the present invention will become clear from the description of this specification.

[0009] -Methods for solving the problem-

[0010] One embodiment of the present invention is as follows.

[0011] [1] A battery module comprising: a battery cell; a fuse electrically connected to the battery cell and extending in a given direction; and a heat-resistant member at least partially surrounding the fuse in the given direction.

[0012] [2] The battery module according to [1], further comprising: a voltage detection unit electrically connected to the battery cell; and a holder that holds the voltage detection unit, wherein at least a portion of the heat-resistant body is provided on the holder.

[0013] [3] The battery module according to [1] or [2], further comprising a housing for housing the battery cell, wherein the housing includes at least a portion of the heat-resistant body.

[0014] -Effects of the Invention-

[0015] According to the above aspect of the present invention, it is possible to suppress the influence of scattering of the fuse on members surrounding the fuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a perspective view of a battery module according to the embodiment.

[0017] Figure 2 It is an exploded perspective view of a battery module according to the embodiment.

[0018] Figure 3 It is an exploded enlarged perspective view of the right front portion of the battery module according to the embodiment.

[0019] Figure 4 yes Figure 1 AA cross-sectional view.

[0020] Figure 5 Yes Figure 4 FIG. 1 is a diagram of a modified example of . DETAILED DESCRIPTION

[0021] Hereinafter, embodiments and modifications of the present invention will be described using the accompanying drawings. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

[0022] Figure 1 It is a perspective view of the battery module 1 according to the embodiment. Figure 2 It is an exploded perspective view of the battery module 1 according to the embodiment. Figure 3 It is an exploded enlarged perspective view of the right front portion of the battery module 1 according to the embodiment.

[0023] For purposes of illustration, arrows indicating the X, Y, and Z directions are shown in each figure. Hereinafter, unless otherwise specified, the tip of an arrow indicating the X direction will be referred to as the rear side of the battery module 1, and the base of an arrow indicating the X direction will be referred to as the front side of the battery module 1. The Y direction is perpendicular to the X direction. The Y direction is the left-right direction of the battery module 1. Hereinafter, unless otherwise specified, the tip of an arrow indicating the Y direction will be referred to as the left side of the battery module 1, and the base of an arrow indicating the Y direction will be referred to as the right side of the battery module 1. The Z direction is perpendicular to both the X and Y directions. The Z direction is the vertical direction of the battery module 1. Hereinafter, unless otherwise specified, the tip of an arrow indicating the Z direction will be referred to as the top side of the battery module 1, and the base of an arrow indicating the Z direction will be referred to as the bottom side of the battery module 1. Hereinafter, as appropriate, directions perpendicular to the X direction will be referred to as the YZ plane direction, directions perpendicular to the Y direction will be referred to as the ZX plane direction, and directions perpendicular to the Z direction will be referred to as the XY plane direction. In addition, the relationship between the X direction, the Y direction, and the Z direction and the front-rear direction, the left-right direction, and the up-down direction of the battery module 1 is not limited to the above-described example.

[0024] Reference Figures 1 to 3 , the structure of the battery module 1 is described.

[0025] The battery module 1 includes a cell stack 10 , a front voltage detection device 20 , a rear voltage detection device 20 ′, and a housing 30 .

[0026] like Figure 2 As shown, the cell stack 10 includes a plurality of battery cells 100 and a plurality of compression pads 110. The battery cells 100 and the compression pads 110 are arranged alternately in the Y direction. Compression pads 110 are positioned on both sides of each battery cell 100 in the Y direction. The battery cells 100 and the compression pads 110 are compressed in the Y direction by the right plate 330 and the left plate 340 described later. This suppresses displacement of the battery cells 100 in the ZX plane.

[0027] like Figure 2 As shown, the long side of each battery cell 100 is substantially parallel to the X direction. The short side of each battery cell 100 is substantially parallel to the Z direction. The thickness of each battery cell 100 is substantially parallel to the Y direction. Multiple battery cells 100 are stacked in the Y direction. The shape of each battery cell 100 is not limited to this example.

[0028] Each battery cell 100 includes a battery element (not shown), an exterior member 102, a positive electrode tab 104, and a negative electrode tab 106. The battery element includes a plurality of positive electrodes and a plurality of negative electrodes (not shown) alternately stacked in the Y direction, and a separator (not shown) located between the positive and negative electrodes adjacent in the Y direction. The exterior member 102 seals the battery element and the electrolyte (not shown). The positive electrode tab 104 is electrically connected to the positive electrode of the battery element. The positive electrode tab 104 extends from one of the two sides of the exterior member 102 in the X direction. The negative electrode tab 106 is electrically connected to the negative electrode of the battery element. The negative electrode tab 106 extends from the other of the two sides of the exterior member 102 in the X direction. However, the structure of each battery cell 100 is not limited to this example.

[0029] In an embodiment, a plurality of cell groups 100G are connected in series from a cell group 100G located at one end in the Y direction to a cell group 100G located at the other end in the Y direction. Each cell group 100G includes a plurality of battery cells 100 connected in parallel. In an embodiment, each cell group 100G includes two battery cells 100 adjacent to each other in the Y direction. The two positive electrode tabs 104 extending from the two battery cells 100 included in each cell group 100G face the same side in the X direction. The two negative electrode tabs 106 extending from the two battery cells 100 included in each cell group 100G face the same side in the X direction. The positive electrode tab 104 and negative electrode tab 106 extending from one of the cell groups 100G adjacent to each other in the Y direction and the positive electrode tab 104 and negative electrode tab 106 extending from the other cell group 100G adjacent to each other in the Y direction face opposite sides in the X direction. Two adjacent cell groups 100G in the Y direction include tab groups 108 located in front of or behind the two cell groups 100G. The tab groups 108 include positive electrode tabs 104 and negative electrode tabs 106 joined to each other. The positive electrode tabs 104 and negative electrode tabs 106 included in the tab groups 108 are joined to each other by, for example, laser welding. Therefore, the plurality of tab groups 108 located in front of the cell stack 10 and the plurality of tab groups 108 located in the rear of the cell stack 10 are arranged alternately.

[0030] In the embodiment, positive electrode tabs 104 are extended forward from the two battery cells 100 located at the right end of the cell stack 10. Hereinafter, these positive electrode tabs 104 are referred to as terminal positive electrode tabs 104T, as needed. However, the number of terminal positive electrode tabs 104T may be only one, or three or more. Furthermore, negative electrode tabs 106 are extended rearward from the two battery cells 100 located at the left end of the cell stack 10. Hereinafter, these negative electrode tabs 106 are referred to as terminal negative electrode tabs 106T, as needed. However, the number of terminal negative electrode tabs 106T may be only one, or three or more.

[0031] The structure of the monomer stack 10 is not limited to the above-mentioned example. For example, each monomer group 100G may also include three or more battery cells 100 connected in parallel. Alternatively, a plurality of single battery cells 100 may be connected in series from the battery cell 100 located at one end in the Y direction to the battery cell 100 located at the other end in the Y direction. In addition, the positions of the terminal positive electrode tab 104T and the terminal negative electrode tab 106T are not limited to the above-mentioned examples. The positions of the terminal positive electrode tab 104T and the terminal negative electrode tab 106T vary according to the number of monomer groups 100G. For example, depending on the number of monomer groups 100G, both the terminal positive electrode tab 104T and the terminal negative electrode tab 106T are arranged in front of or behind the monomer stack 10.

[0032] like Figure 2 As shown, the front voltage detection device 20 includes a front holding body 210 , a plurality of front voltage detection units 220 , a plurality of front voltage detection lines 222 , a front connector 224 , and a positive bus bar 230 .

[0033] The front holding body 210 is disposed in front of the cell stack 10. The front holding body 210 defines a plurality of front openings 212. The plurality of tab groups 108 located in the front of the cell stack 10 are exposed forward through each of the plurality of front openings 212. The front holding body 210 integrally holds a plurality of front voltage detection units 220 and a plurality of front voltage detection lines 222.

[0034] A plurality of front voltage detection units 220 are mounted on the front retaining body 210. The plurality of front voltage detection units 220 are respectively joined to the front surface of each of the plurality of tab groups 108 located in front of the cell stack 10 by, for example, laser welding. The plurality of front voltage detection units 220 are electrically connected to the front connector 224 via a plurality of front voltage detection lines 222. The plurality of front voltage detection lines 222 are routed through the front retaining body 210. In an embodiment, by setting the front retaining body 210 at an appropriate position relative to the cell stack 10, the plurality of front voltage detection units 220 can be respectively arranged at an appropriate position relative to each of the plurality of tab groups 108 located in front of the cell stack 10.

[0035] The positive bus bar 230 is located at the right end of the front retaining body 210. It is generally L-shaped. Specifically, the positive bus bar 230 includes a front horizontal conductor 232 and a front vertical conductor 234. The front horizontal conductor 232 extends generally parallel to the Y direction. The front vertical conductor 234 extends downward from the right end of the front horizontal conductor 232 and generally parallel to the Z direction.

[0036] The front transverse conductor 232 functions as a terminal for electrical connection to external devices such as other battery modules. Specifically, a fastening hole 232a is provided at the left end of the front transverse conductor 232. Fasteners (not shown) can be installed in fastening hole 232a to fasten busbars (not shown) that are electrically connected to external devices such as other battery modules (not shown).

[0037] like Figure 3 As shown, the front transverse conductor 232 includes a fuse 233. The fuse 233 is located to the right of the fastening hole 232a. The fuse 233 extends approximately parallel to the Y direction. A notch is provided in the front transverse conductor 232 behind the fuse 233. Therefore, the cross-section of the fuse 233 perpendicular to the Y direction is smaller than the cross-sections perpendicular to the Y direction on either side of the fuse 233 in the front transverse conductor 232. Therefore, when a current exceeding a predetermined value flows through the fuse 233, the fuse 233 melts. However, the structure of the fuse 233 is not limited to this example. For example, the fuse 233 may be defined by a notch provided in front of the front transverse conductor 232. Alternatively, the fuse 233 may be defined by notches provided both in front and behind the front transverse conductor 232. In this example, the fuse 233 is located approximately in the center of the front transverse conductor 232 in the X direction. However, the fuse 233 may be offset in the X direction from the approximately center portion of the front transverse conductor 232 in the X direction. Alternatively, the thickness of the front transverse conductor 232 in the Z direction may be partially thinned. In this case, the fuse 233 forms a portion of the front transverse conductor 232 where the thickness in the Z direction is locally thinner.

[0038] The front columnar conductor 234 is electrically connected to the terminal positive electrode tab 104T. The terminal positive electrode tab 104T is located to the right of the front columnar conductor 234. In the embodiment, the terminal positive electrode tab 104T and the front columnar conductor 234 are joined by laser welding. However, the joining method between the terminal positive electrode tab 104T and the front columnar conductor 234 is not limited to laser welding.

[0039] The rear voltage detection device 20' is identical to the front voltage detection device 20 except for the following: The rear voltage detection device 20' includes a rear holding body 210', a plurality of rear voltage detection portions 220', a plurality of rear voltage detection lines 222', a rear connector 224', and a negative bus bar 230'.

[0040] The rear retaining member 210′ ​​is disposed at the rear of the cell stack 10. The rear retaining member 210′ ​​defines a plurality of rear openings 212′. The plurality of tab groups 108 located at the rear of the cell stack 10 pass through each of the plurality of rear openings 212′ and are exposed rearward. The rear retaining member 210′ ​​integrally retains a plurality of rear voltage detection units 220′ and a plurality of rear voltage detection lines 222′.

[0041] A plurality of rear voltage detection parts 220' are mounted on the rear retaining body 210'. The plurality of rear voltage detection parts 220' are respectively joined to the rear surface of each of the plurality of tab groups 108 located at the rear of the monomer stack 10 by, for example, laser welding. The plurality of rear voltage detection parts 220' are electrically connected to the rear connector 224' via a plurality of rear voltage detection lines 222'. The plurality of rear voltage detection lines 222' are laid out via the rear retaining body 210'. In an embodiment, by setting the rear retaining body 210' at an appropriate position relative to the monomer stack 10, the plurality of rear voltage detection parts 220' can be respectively arranged at an appropriate position relative to each of the plurality of tab groups 108 located at the rear of the monomer stack 10.

[0042] The negative busbar 230' is located at the left end of the rear retaining body 210'. It is roughly L-shaped. It includes a rear horizontal conductor 232' and a rear vertical conductor 234'. The rear horizontal conductor 232' extends roughly parallel to the Y direction. The rear vertical conductor 234' extends downward from the left end of the rear horizontal conductor 232', roughly parallel to the Z direction.

[0043] The rear horizontal conductor 232' functions as a terminal for electrically connecting to external devices such as other battery modules. Similar to the front horizontal conductor 232, the rear horizontal conductor 232' includes a fuse.

[0044] The rear columnar conductor 234' is electrically connected to the terminal negative electrode tab 106T. The terminal negative electrode tab 106T is located to the left of the rear columnar conductor 234'. In the embodiment, the terminal negative electrode tab 106T and the rear columnar conductor 234' are joined by laser welding. However, the joining method between the terminal negative electrode tab 106T and the rear columnar conductor 234' is not limited to laser welding.

[0045] The container 30 has a front plate 310, a rear plate 320, a right plate 330, a left plate 340, a lower plate 350 and an upper plate 360. Figure 4 As will be described later, the housing 30 further includes a heat-resistant coating 311 .

[0046] The front plate 310 covers the unit stack 10 and the front voltage detection device 20 from the front. The front plate 310 is, for example, a metal plate such as an aluminum plate.

[0047] The rear plate 320 covers the unit laminate 10 and the rear voltage detection device 20' from the rear. The rear plate 320 is, for example, a metal plate such as an aluminum plate.

[0048] The right plate 330 covers the single-unit laminate 10, the front voltage detection device 20, and the rear voltage detection device 20' from the right. The right plate 330 is made of a conductive material such as metal.

[0049] The left plate 340 covers the single-unit laminate 10, the front voltage detection device 20, and the rear voltage detection device 20' from the left. The left plate 340 is made of a conductive material such as metal.

[0050] The lower plate 350 covers the cell stack 10, the front voltage detection device 20, and the rear voltage detection device 20' from below. The lower plate 350 is made of a conductive material such as metal. A thermally conductive adhesive 352 is disposed between the upper surface of the lower plate 350 and the lower end of the cell stack 10. This allows heat generated by the cell stack 10 to be dissipated downward toward the battery module 1 through the thermally conductive adhesive 352.

[0051] The upper plate 360 ​​covers the unit stack 10, the front voltage detection device 20, and the rear voltage detection device 20' from above. The upper plate 360 ​​is made of a conductive material such as metal.

[0052] Figure 4 yes Figure 1 AA section view. Figure 4 In the figure, a white circle with an X indicating the Y direction means that the direction from the base end toward the front end of the arrow indicating the Y direction is from the front to the back of the paper.

[0053] The front holding body 210 is provided with a surrounding heat-resistant body 211. Figure 4 In the example shown, the front retaining member 210 and the surrounding heat-resistant member 211 are integrally formed. The surrounding heat-resistant member 211 is made of a heat-resistant material such as a heat-resistant resin. Examples of heat-resistant materials include polypropylene (PP), polybutylene terephthalate (PBT), modified polyphenylene ether, silicone resin, and silica fiber. The surrounding heat-resistant member 211 may be made of a single heat-resistant material as exemplified here, or it may be made of a plurality of heat-resistant materials as exemplified here. The melting point of the heat-resistant material is, for example, 150°C or higher, preferably 200°C or higher.

[0054] The heat-resistant body 211 surrounds at least a portion of the fuse 233 in the Y direction. Figure 4In the example shown, the surrounding heat-resistant body 211 surrounds the fuse 233 in the Y direction, excluding the front of the fuse 233. In other words, the surrounding heat-resistant body 211 is open toward the front. Therefore, when viewed from the Y direction, the surrounding heat-resistant body 211 has a roughly U-shaped or N-shaped shape.

[0055] exist Figure 4 In the example shown, the surrounding heat-resistant body 211 extends along the entire circumference of the fuse 233 in the Y direction and is separated from the fuse 233. Therefore, when viewed in the Y direction, a gap exists between the fuse 233 and the surrounding heat-resistant body 211, except in front of the fuse 233. Therefore, as the fuse 233 melts, it can fall into the gap below the fuse 233. Therefore, compared to a case where the fuse 233 and the surrounding heat-resistant body 211 are in contact with each other, the fuse 233 can be shut off more easily by the melting of the fuse 233. However, the surrounding heat-resistant body 211 may also be in contact with the fuse 233, at least partially, in addition to the lower surface of the fuse 233.

[0056] A protrusion 310a is provided on the rear surface of the upper end portion of the front plate 310. The protrusion 310a protrudes rearward from the rear surface of the upper end portion of the front plate 310. Protrusion 310a increases the contact area between the upper surface of the upper end portion of the front plate 310 and the lower surface of the front end portion of the upper plate 360 ​​compared to when protrusion 310a is not provided. Therefore, when protrusion 310a is provided, the upper surface of the upper end portion of the front plate 310 and the lower surface of the front end portion of the upper plate 360 ​​can be joined more easily using welding or other joining methods than when protrusion 310a is not provided.

[0057] The heat-resistant coating 311 is provided on the rear surface of the front plate 310. The heat-resistant coating 311 comprises a heat-resistant material such as a heat-resistant resin. Examples of the heat-resistant material of the heat-resistant coating 311 include the materials exemplified for the surrounding heat-resistant body 211. The heat-resistant material forming the heat-resistant coating 311 may be different from or the same as the heat-resistant material forming the surrounding heat-resistant body 211. In one example, the heat-resistant coating 311 is adhered to the rear surface of the front plate 310. Alternatively, the heat-resistant coating 311 may be formed on the rear surface of the front plate 310 by a deposition method such as evaporation.

[0058] The heat-resistant coating 311 covers at least a portion of the rear surface of the front plate 310. Figure 4 In the example shown, the upper end of the heat-resistant coating 311 is located in front of the fuse 233. Therefore, the surrounding heat-resistant body 211 and the heat-resistant coating 311 together surround at least a portion of the fuse 233 in the Y direction. This can suppress the effects of scattering of the fuse 233 on surrounding components.

[0059] exist Figure 4 In the example shown, the heat-resistant covering 311 exposes the lower surface of the protrusion 310a. Therefore, compared to a case where the heat-resistant covering 311 covers the lower surface of the protrusion 310a, the heat-resistant covering 311 can be more easily positioned on the rear surface of the front plate 310. In one example, the distance between the fuse 233 and the protrusion 310a can be set such that scattered debris from the fuse 233 does not reach the protrusion 310a. In this example, even if at least a portion of the protrusion 310a is exposed from the heat-resistant covering 311, the impact of scattered debris from the fuse 233 on the protrusion 310a can be suppressed.

[0060] In the embodiment, the surrounding heat-resistant body 211 is provided on the front retaining body 210. Therefore, the number of components in the battery module 1 can be reduced compared to a case where a member separate from the front retaining body 210 is provided for providing the surrounding heat-resistant body 211. Similarly, the covering heat-resistant body 311 is provided on the front plate 310. Therefore, the number of components in the battery module 1 can be reduced compared to a case where a member separate from the front plate 310 is provided for providing the covering heat-resistant body 311.

[0061] The method of at least partially surrounding the fuse 233 with a heat-resistant body in the Y direction is not limited to the method according to the embodiment.

[0062] For example, the heat-resistant covering 311 may not be provided. In this example, for example, a portion surrounding the heat-resistant covering 211 may be located in front of the fuse 233. Alternatively, the front plate 310 itself may be heat-resistant. Alternatively, the gap between the fuse 233 and the rear surface of the front plate 310 may be set to a distance sufficient to prevent scattered debris from reaching the rear surface of the front plate 310. In this example, the heat-resistant covering 211 may not be provided in front of the fuse 233.

[0063] In the embodiment, the heat-resistant body is described as being provided around the fuse 233 of the positive electrode bus bar 230. However, a heat-resistant body similar to that described in the embodiment may also be provided around a fuse other than the fuse 233 of the positive electrode bus bar 230. For example, a heat-resistant body may also be provided around the fuse of the negative electrode bus bar 230'.

[0064] Figure 5 Yes Figure 4 FIG. 1 is a diagram of a modified example of .

[0065] exist Figure 5In the example shown, the upper end of the heat-resistant covering 311A ​​is bent rearward at a substantially right angle when viewed in the Y direction. In other words, the upper end of the heat-resistant covering 311A ​​forms a roughly L-shaped shape when viewed in the Y direction. Therefore, the upper end of the heat-resistant covering 311A ​​covers the lower surface of the protrusion 310a. This makes it easier to protect the protrusion 310a from flying debris from the fuse 233, compared to a case where the upper end of the heat-resistant covering 311A ​​does not cover the lower surface of the protrusion 310a.

[0066] As mentioned above, although embodiment and modification of this invention were described with reference to drawings, these are illustrations of this invention, and various structures other than the above-mentioned can also be adopted.

[0067] This application claims priority based on Japanese Patent Application No. 2023-021503, filed on February 15, 2023, the entire disclosure of which is incorporated herein.

[0068] -Description of Reference Numerals-

[0069] 1: Battery module, 10: Cell stack, 20: Front voltage detection device, 20': Rear voltage detection device, 30: Container, 100: Battery cell, 100G: Cell group, 102: Exterior component, 104: Positive electrode tab, 104T: Terminal positive electrode tab, 106: Negative electrode tab, 106T: Terminal negative electrode tab, 108: Tab group, 110: Compression pad, 210: Front retaining body, 210': Rear retaining body, 211: Surrounding heat-resistant body, 212: Front opening, 212': Rear opening, 220: Front voltage detection unit, 220': Rear voltage detection unit, 222 : Front voltage detection line, 222´: Rear voltage detection line, 224: Front connector, 224´: Rear connector, 230: Positive bus bar, 230´: Negative bus bar, 232: Front horizontal conductor, 232´: Rear horizontal conductor, 232a: Fastening hole, 233: Fuse, 234: Front vertical conductor, 234´: Rear vertical conductor, 310: Front plate, 310a: Protrusion, 311: Covered heat-resistant body, 311A: Covered heat-resistant body, 320: Rear plate, 330: Right plate, 340: Left plate, 350: Lower plate, 352: Thermally conductive adhesive, 360: Upper plate.

Claims

1. A battery module, characterized in that: have: Battery cells; a fuse electrically connected to the battery cell and extending in a given direction; and A heat-resistant body at least partially surrounds the fuse in the given direction.

2. The battery module according to claim 1, wherein: The battery module further comprises: a voltage detection unit electrically connected to the battery cell; and a holding body holding the voltage detection unit, At least a portion of the heat-resistant body is provided on the holding body.

3. The battery module according to claim 1 or 2, wherein: The battery module further comprises: a housing for housing the battery cells; The housing includes at least a portion of the heat-resistant body.

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