Battery module

Abstract

To provide a battery module that can prevent gas leaking outside the exhaust duct from coming into contact with the energy storage cell. [Solution] The energy storage device 1 comprises a plurality of energy storage cells 110 arranged in a unidirectional line, a smoke exhaust duct 124A that defines the exhaust path for gas released from the energy storage cells, and a cover member 200 that covers the smoke exhaust duct. Each energy storage cell 110 has a valve mounting surface 112a on which a safety valve SV is provided. The smoke exhaust duct 124A has a plurality of duct elements 124, each covering a safety valve and connected to one another. The cover member 200 has a contact portion 215 that contacts the valve mounting surface.

Description

Technical Field

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

Background Art

[0002] For example, Japanese Unexamined Patent Application Publication No. 2022-76127 discloses a power storage module including a plurality of secondary batteries and a plurality of resin frames. Each resin frame has a partition portion that partitions between a pair of adjacent secondary batteries and a duct element connected to the upper portion of the partition portion. The duct element covers a safety valve formed on the upper surface of each secondary battery. The plurality of duct elements are connected to each other to form a smoke exhaust duct. The smoke exhaust duct forms a smoke exhaust path for discharging gas generated from the secondary batteries.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power storage module described in Japanese Unexamined Patent Application Publication No. 2022-76127, there is a concern that gas may leak out of the smoke exhaust path between adjacent duct elements.

[0005] An object of the present disclosure is to provide a battery module capable of suppressing gas leaked outside the smoke exhaust duct from contacting the power storage cells.

Means for Solving the Problems

[0006] <00^0033>A battery module according to one aspect of the present disclosure comprises a plurality of energy storage cells arranged in a unidirectional manner, a smoke exhaust duct defining a path for exhausting gas released from the energy storage cells, and a cover member covering the smoke exhaust duct, wherein each of the plurality of energy storage cells has a valve mounting surface on which a safety valve is provided, the smoke exhaust duct has a plurality of duct elements, each covering the safety valve and connected to one another, and the cover member has a contact portion that contacts the valve mounting surface. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a battery module that can prevent gas leaking outside the exhaust duct from coming into contact with the energy storage cell. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view showing an energy storage device including a battery module in one embodiment of the present disclosure. [Figure 2] This is a schematic plan view showing a portion of the battery module. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 2. [Figure 4] Figure 2 shows a cross-sectional view along line IV-IV. [Figure 5] This is a perspective view showing a schematic representation of the cover body. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described with reference to the drawings. In the drawings referred to below, the same or equivalent components are given the same number.

[0010] Figure 1 is a schematic perspective view of an energy storage device including a battery module in one embodiment of the present disclosure. Figure 2 is a schematic plan view of a portion of the battery module. Figure 3 is a cross-sectional view taken along line III-III in Figure 2. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 2. This energy storage device 1 is mounted, for example, in a vehicle.

[0011] As shown in Figures 1 to 4, the energy storage device 1 comprises at least one energy storage module 10 and a housing 20. In this embodiment, the at least one energy storage module 10 includes two energy storage modules 10.

[0012] The housing 20 houses each energy storage module 10. The housing 20 has a lower case 22 and an upper cover 24 (see Figures 3 and 4). The lower case 22 is open upwards. The upper cover 24, together with the lower case 22, houses each energy storage module 10 in a sealed state. Note that the upper cover 24 is not shown in Figure 1.

[0013] Each energy storage module 10 comprises an energy storage stack 100, a cover member 200, a thermistor 300, and a busbar module 400. Note that the busbar module 400 is not shown in Figure 1.

[0014] The energy storage stack 100 includes a plurality of energy storage cells 110, a plurality of resin frames 120, a first end plate 131, and a second end plate 132.

[0015] Multiple energy storage cells 110 are arranged in a line in one direction (hereinafter referred to as "first direction DR1"). Examples of energy storage cells 110 include lithium-ion batteries. Each energy storage cell 110 has a cell case 112 and a pair of external terminals 114.

[0016] The cell case 112 houses the electrode body and the electrolytic solution. The cell case 112 is formed in a rectangular shape. As shown in FIGS. 3 and 4, the cell case 112 has a valve installation surface 112a. A safety valve SV is provided on the valve installation surface 112a. In the present embodiment, the valve installation surface 112a is constituted by the upper surface of the cell case 112. However, the valve installation surface 112a may be constituted by the side surface of the cell case 112 in the second direction DR2 or the bottom surface of the cell case 112. Note that the second direction DR2 is a direction orthogonal to both the first direction DR1 and the vertical direction.

[0017] A pair of external terminals 114 are provided on the valve installation surface 112a of the cell case 112. In the present embodiment, each external terminal 114 protrudes upward from the valve installation surface 112a. One of the pair of external terminals 114 is a positive electrode terminal, and the other is a negative electrode terminal. The positive electrode terminal is provided on one side of the safety valve SV in the second direction DR2. The negative electrode terminal is provided on the other side of the safety valve SV in the second direction DR2.

[0018] Each resin frame 120 is arranged so as to be adjacent to the power storage cell 110 in the first direction DR1. Each resin frame 120 is arranged between a pair of power storage cells 110 adjacent to each other in the first direction DR1. Each resin frame 120 has a partition portion 122 and a duct element 124.

[0019] The partition portion 122 is made of an insulating material (resin). The partition portion 122 partitions between the power storage cells 11% adjacent to each other in the first direction DR1.

[0020] The duct element 124 is connected to the partition portion 122. Specifically, the duct element 124 protrudes from the partition portion 122 toward the valve installation surface 112a side of the cell case 112. In the present embodiment, the duct element 124 is connected to the upper portion of the partition portion 122. As shown in FIGS. 3 and 4, the duct element 124 has a shape that covers the safety valve SV of each power storage cell 110.

[0021] Each duct element 124 is connected to a duct element 124 adjacent in the first direction DR1. A plurality of duct elements 124 constitute a smoke exhaust duct 124A by being connected to each other. In other words, the smoke exhaust duct 124A is composed of a plurality of duct elements 124 connected to each other. The smoke exhaust duct 124A is provided on a plurality of power storage cells 110 and defines an exhaust path C (see FIGS. 3 and 4) for the gas discharged from the safety valve SV of the power storage cell 110.

[0022] The first end plate 131 and the second end plate 132 are arranged outside the plurality of power storage cells 110 in the first direction DR1. The first end plate 131 is in contact with one end of the smoke exhaust duct 124A in the first direction DR1. The first end plate 131 closes the opening at one end side of the duct element 124. The second end plate 132 is separated from the other end of the duct element 124 in the first direction DR1. A smoke exhaust pipe (not shown) is provided in the gap between the second end plate 132 and the smoke exhaust duct 124A.

[0023] The thermistor 300 can detect the temperature of the power storage cell 110. The thermistor 300 is provided outside the exhaust path C. The thermistor 300 is provided at a portion of the cell case 112 that is separated from the smoke exhaust duct 124A. As shown in FIGS. 2 and 4, the thermistor 300 is provided so as to contact the valve installation surface 112a of the cell case 112.

[0024] The cover member 200 covers the smoke exhaust duct 124A. In FIG. 1, the illustration of one cover member 200 is omitted. As shown in FIGS. 3 and 4, the cover member 200 has a cover body 210 and a seal member 220.

[0025] FIG. 5 is a perspective view schematically showing the cover body 210. The cover body 210 is made of, for example, non-combustible paper. The non-combustible paper is formed by pressing ceramic fibers into a sheet shape. The cover body 210 has a covering portion 212 and a flange portion 214.

[0026] The covering portion 212 covers the exhaust duct 124A. The covering portion 212 extends from one end to the other end of the exhaust duct 124A in the first direction DR1. The covering portion 212 has a pair of upright portions 212a and a connecting portion 212b.

[0027] The pair of upright portions 212a are positioned to sandwich the exhaust duct 124A in the second direction DR2. As shown in Figure 4, a notch 212s is provided in the portion of the upright portion 212a facing the thermistor 300. The notch 212s creates a gap S between the valve mounting surface 112a and the upright portion 212a.

[0028] The connecting portion 212b connects the upper ends of the pair of upright portions 212a.

[0029] The flange portion 214 is connected to the covering portion 212. The flange portion 214 protrudes outward in the second direction DR2 from the end of each upright portion 212a on the valve mounting surface 112a side.

[0030] As shown in Figures 2 and 5, the flange portion 214 is provided with slits 214s. The slits 214s are provided in the portion of the flange portion 214 facing the thermistor 300. As shown in Figure 2, the flange portion 214 is provided with three slits 214s. The first slit 214s is provided at one end of one flange portion 214 in the first direction DR1. The second slit 214s is provided at the other end of the other flange portion 214 in the first direction DR1. The third slit 214s is provided in the middle portion of one flange portion 214 in the first direction DR1.

[0031] The sealing member 220 is provided between the flange portion 214 and the valve mounting surface 112a. The sealing member 220 is made of sponge or the like. A slit is also formed in the portion of the sealing member 220 that overlaps with the slit 214s.

[0032] To prevent gas leaking from between adjacent duct elements 124 from diffusing into the housing 20 or coming into contact with the external terminals 114, the cover member 200 has a contact portion 215 that comes into contact with the valve mounting surface 112a. In this embodiment, the flange portion 214 and the sealing member 220 constitute the contact portion 215. As shown in Figure 2, the thermistor 300 is positioned such that at least a portion of the thermistor 300 faces the contact portion 215 in the first direction DR1.

[0033] The busbar module 400 is attached to the energy storage stack 100. In this embodiment, the busbar module 400 is fixed to the top of the energy storage stack 100. Note that the busbar module 400 is not shown in Figure 1. The busbar module 400 has a plurality of busbars 410 (see Figure 2) and a busbar case 420.

[0034] Each busbar 410 electrically connects a pair of adjacent energy storage cells 110 from among the multiple energy storage cells 110. As shown in Figure 2, each busbar 410 connects the positive external terminal 114 of one energy storage cell 110 to the negative external terminal 114 of an adjacent energy storage cell 110. Therefore, each energy storage cell 110 included in the energy storage stack 100 is connected in series by each busbar 410. Note that only some of the busbars 410 are shown in Figure 2.

[0035] The busbar case 420 holds a plurality of busbars 410. The busbar case 420 is made of, for example, synthetic resin. The busbar case 420 may be fixed to the resin frame 120. The busbar case 420 has a wall portion 422 and a pressing portion 424.

[0036] The wall portion 422 is provided in a position that sandwiches the cover member 200 together with the valve mounting surface 112a. In this embodiment, the wall portion 422 is positioned above the cover member 200. As shown in Figures 3 and 4, the wall portion 422 is located above the covering portion 212. As shown in Figure 3, the wall portion 422 may include a projection 423 that contacts the upper surface of the covering portion 212.

[0037] The pressing portion 424 presses the contact portion 215 against the valve mounting surface 112a. In this embodiment, the busbar case 420 has a pair of pressing portions 424. Each pressing portion 424 extends from the wall portion 422 toward the contact portion 215. The lower end of each pressing portion 424 is in contact with the flange portion 214. Each pressing portion 424 is located outside the upright portion 212a in the second direction DR2. Each pressing portion 424 faces the upright portion 212a. A small clearance is provided between the pressing portion 424 and the upright portion 212a.

[0038] In the energy storage device 1 described above, when gas is released from the safety valve SV of any of the energy storage cells 110, the gas flows through the discharge path C in the smoke exhaust duct 124A towards the smoke exhaust pipe. At this time, some of the gas may leak out of the smoke exhaust duct 124A from between adjacent duct elements 124. In this embodiment, since the cover member 200 covers the smoke exhaust duct 124A, the gas that leaks out of the smoke exhaust duct 124A is prevented from diffusing into the housing 20 or coming into contact with the external terminals 114.

[0039] Furthermore, since the cover member 200 is provided with a notch 212s, the gas that flows out of the cover member 200 through the gap S formed by this notch 212s comes into contact with the thermistor 300. Therefore, the thermistor 300 can detect the generation of gas.

[0040] Those skilled in the art will understand that the exemplary embodiments described above are specific examples of the following embodiments.

[0041] [Aspect 1] Multiple energy storage cells arranged in a line in one direction, A smoke exhaust duct that defines the exhaust path for the gas released from the energy storage cell, The system comprises a cover member that covers the smoke exhaust duct, Each of the plurality of energy storage cells has a valve mounting surface on which a safety valve is provided. The smoke exhaust duct has a plurality of duct elements, each covering the safety valve and connected to one another. The cover member has a contact portion that contacts the valve mounting surface, and is used as an energy storage device.

[0042] In this energy storage device, the cover member covers the exhaust duct, and the cover member has contact points. Therefore, even if gas leaks out of the exhaust duct from between adjacent duct elements, contact with the external terminals of the energy storage cell is suppressed.

[0043] [Aspect 2] The system further includes a busbar module that includes a busbar that electrically connects a pair of adjacent energy storage cells among the plurality of energy storage cells, Each of the energy storage cells includes a pair of external terminals provided on the valve mounting surface, The energy storage device according to embodiment 1, wherein the busbar module includes a pressing portion that presses the contact portion against the valve mounting surface.

[0044] In this embodiment, by connecting busbar modules to multiple energy storage cells, the pressing portion presses the contact portion against the valve mounting surface, thereby more reliably suppressing gas leakage outside the cover member.

[0045] [Aspect 3] The busbar module further includes a wall portion provided at a position that sandwiches the cover member together with the valve mounting surface, The energy storage device according to embodiment 2, wherein the pressing portion extends from the wall portion toward the contact portion.

[0046] In this embodiment, the wall portion restricts the cover member from separating from the valve mounting surface due to the pressure of the gas released from the safety valve.

[0047] [Aspect 4] The system further includes a thermistor located outside the aforementioned discharge path, The energy storage device according to any one of embodiments 1 to 3, wherein the cover member has a notch provided in a portion facing the thermistor.

[0048] In this embodiment, the gas that flows out of the cover member through the notch in the cover member comes into contact with the thermistor, making it possible to detect the generation of gas by the thermistor.

[0049] [Aspect 5] The cover member further includes a covering portion that covers the exhaust duct, The energy storage device according to embodiment 4, wherein the thermistor is separated from the covering portion.

[0050] [Aspect 6] The contact portion is connected to the covering portion, The energy storage device according to embodiment 5, wherein at least a portion of the thermistor is positioned to face the contact portion in the one direction.

[0051] In this embodiment, the gas effectively contacts the thermistor while avoiding interference between the thermistor and the covering.

[0052] [Aspect 7] The cover member further includes a covering portion that covers the exhaust duct, The aforementioned contact portion is The flange portion connected to the covering portion, The energy storage device according to embodiment 1, further comprising a sealing member provided between the flange portion and the valve mounting surface.

[0053] [Aspect 8] The power storage device according to embodiments 1 to 7, wherein the cover member is made of non-combustible paper.

[0054] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of this disclosure is defined by the claims rather than the description of the embodiments above, and includes all modifications within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0055] 1 Energy storage device, 10 Energy storage module, 20 Housing, 100 Energy storage stack, 110 Energy storage cell, 112 Cell case, 112a Valve mounting surface, 114 External terminal, 120 Resin frame, 122 Partition, 124 Duct element, 124A Smoke exhaust duct, 200 Cover member, 210 Cover body, 212 Covering part, 212a Upright part, 212b Connecting part, 212s Notch, 214 Flange part, 214s Slit, 215 Contact part, 220 Seal member, 300 Thermistor, 400 Busbar module, 410 Busbar, 420 Busbar case, 422 Wall part, 424 Pressing part, C Discharge path, S Gap, SV Safety valve.

Claims

1. Multiple energy storage cells arranged in a line in one direction, A smoke exhaust duct that defines the exhaust path for the gas released from the aforementioned energy storage cell, The system comprises a cover member that covers the smoke exhaust duct, Each of the plurality of energy storage cells has a valve mounting surface on which a safety valve is provided. The smoke exhaust duct has a plurality of duct elements, each covering the safety valve and connected to one another. The cover member has a contact portion that contacts the valve mounting surface, and is an energy storage device.

2. The system further includes a busbar module that includes a busbar that electrically connects a pair of adjacent energy storage cells among the plurality of energy storage cells, Each of the energy storage cells includes a pair of external terminals provided on the valve mounting surface, The energy storage device according to claim 1, wherein the busbar module includes a pressing portion that presses the contact portion against the valve mounting surface.

3. The busbar module further includes a wall portion provided at a position that sandwiches the cover member together with the valve mounting surface, The energy storage device according to claim 2, wherein the pressing portion extends from the wall portion toward the contact portion.

4. The system further includes a thermistor located outside the aforementioned discharge path, The energy storage device according to claim 1, wherein the cover member has a notch provided in a portion facing the thermistor.

5. The cover member further includes a covering portion that covers the exhaust duct, The energy storage device according to claim 4, wherein the thermistor is separated from the covering portion.

6. The contact portion is connected to the covering portion, The energy storage device according to claim 5, wherein at least a portion of the thermistor is positioned to face the contact portion in the one direction.

7. The cover member further includes a covering portion that covers the exhaust duct, The aforementioned contact portion is The flange portion connected to the covering portion, The energy storage device according to claim 1, further comprising a sealing member provided between the flange portion and the valve mounting surface.

8. The energy storage device according to claim 1, wherein the cover member is made of non-combustible paper.

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