Battery pack

Abstract

The present application provides a battery pack, comprising: a supporting assembly, provided with a plurality of first pressure relief holes; first heat insulation members, connected to the supporting assembly; a plurality of battery cells, arranged on the side of the first heat insulation members away from the supporting assembly, wherein an explosion-proof valve of each battery cell is arranged right opposite to a corresponding first pressure relief hole; and a second heat insulation member, connected to the side of the supporting assembly away from the first heat insulation members, wherein at least one of the first heat insulation members and the second heat insulation member seals the plurality of first pressure relief holes.

Description

battery pack

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 2, 2023, with application number 2023229718151. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery pack. Background Art

[0003] The new energy vehicle market has continued to grow in recent years, with sales increasing year by year. As a core component of new energy vehicles, the battery system closely impacts a vehicle's safety and performance.

[0004] In order to ensure the safety of the battery pack, an explosion-proof valve is usually installed at the end of the battery cell. When a battery cell experiences thermal runaway under extreme operating conditions, the high-temperature and high-pressure substances generated inside the battery cell will rush open the explosion-proof valve and release the pressure in time. Technical issues

[0005] The high-temperature and high-pressure substances ejected from the battery cells due to thermal runaway can easily spread to other good battery cells, causing short circuits between the good battery cells and heat spread. Technical Solutions

[0006] The present application provides a battery pack, comprising: a support assembly, having a plurality of first pressure relief holes; a first thermal insulation member connected to the support assembly; a plurality of battery cells, respectively arranged on a side of the first thermal insulation member facing away from the support assembly, and an explosion-proof valve of each battery cell is arranged opposite to the corresponding first pressure relief hole; a second thermal insulation member connected to a side of the support assembly facing away from the first thermal insulation member, and at least one of the first thermal insulation member and the second thermal insulation member seals the plurality of first pressure relief holes. Beneficial effects

[0007] The beneficial effect of the battery pack provided by the present application is that the battery pack seals the first pressure relief hole with a first thermal insulation member and insulates and protects the supporting assembly. When a certain battery cell has thermal runaway, the high-temperature and high-pressure material ejected penetrates the first thermal insulation member and flows into the pressure relief cavity through the corresponding first pressure relief hole. The remaining first thermal insulation members that seal the first pressure relief hole can prevent the high-temperature and high-pressure material in the pressure relief cavity from reverse heat transfer or flowing into the good battery cell. At the same time, the second thermal insulation member can ensure that the high-temperature and high-pressure material in the pressure relief cavity will not penetrate the bottom guard plate, prevent the high-temperature and high-pressure material in the pressure relief cavity from overflowing and damaging the bottom guard plate, thereby preventing short circuits between good battery cells and avoiding heat spread in the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG1 is a schematic diagram of the three-dimensional structure of a battery pack provided in one embodiment of the present application;

[0009] FIG2 is a schematic diagram of an exploded structure of a battery pack provided in one embodiment of the present application;

[0010] Figure 3 is an enlarged view of point B in Figure 2;

[0011] Figure 4 is an enlarged view of point C in Figure 2;

[0012] FIG5 is a schematic cross-sectional view of the structure along line AA in FIG1 ;

[0013] FIG6 is an enlarged view of point D in FIG5.

[0014] Explanation of the accompanying drawings: 10, battery pack; 100, support assembly; 110, first pressure relief hole; 120, bracket; 121, first sub-hole; 122, first extension part; 130, tray; 131, second sub-hole; 140, box body; 200, first thermal insulation member; 210, valve opening part; 220, annular part; 240, rubber stopper; 241, through hole; 250, structural adhesive; 251, mounting hole; 252, clamping part; 300, battery cell; 310, explosion-proof valve; 400, bottom guard plate; 500, third thermal insulation member; 600, pressure relief chamber; 800, support member; 900, second thermal insulation member; 910, second pressure relief hole. Modes for Carrying Out the Invention

[0015] Please refer to Figures 2 and 6. An embodiment of the present application provides a battery pack 10, which includes a support assembly 100, a first thermal insulation member 200, a plurality of battery cells 300 and a second thermal insulation member 900. The support assembly 100 is provided with a plurality of first pressure relief holes 110, the first thermal insulation member 200 is connected to the support assembly 100, and the plurality of battery cells 300 are respectively arranged on the side of the first thermal insulation member 200 away from the support assembly 100, and the explosion-proof valve 310 of each battery cell 300 is arranged opposite to the corresponding first pressure relief hole 110, the second thermal insulation member 900 is connected to the side of the support assembly 100 away from the first thermal insulation member 200, and at least one of the first thermal insulation member 200 and the second thermal insulation member 900 seals the plurality of first pressure relief holes 110. Compared with the related art, the battery pack 10 provided in the present application uses the first thermal insulation member 200 and the second thermal insulation member 900 to insulate and protect the support assembly 100, and the first thermal insulation member 200 and / or the second thermal insulation member 900 seal the first pressure relief hole 110. When a certain battery cell 300 experiences thermal runaway, the high-temperature and high-pressure material ejected breaks through the corresponding first thermal insulation member 200 and / or the second thermal insulation member 900. The remaining first thermal insulation member 200 and / or the second thermal insulation member 900 that seals the first pressure relief hole 110 can prevent the high-temperature and high-pressure material from reversely transferring heat or flowing into the good battery cell 300, thereby avoiding the phenomenon of heat spread in the battery pack 10.

[0016] Exemplarily, as shown in FIG2 , the support assembly 100 includes a bracket 120 , the bracket 120 is provided with a plurality of first sub-holes 121 , the first pressure relief hole 110 includes the first sub-holes 121 , and the first thermal insulation member 200 is attached to the bracket 120 to seal the plurality of first sub-holes 121 .

[0017] In one embodiment, the bracket 120 is a plastic plate, and the plurality of first sub-holes 121 are evenly spaced apart on the bracket 120 to improve space utilization.

[0018] In one embodiment, the support assembly 100 further includes a tray 130, which is attached to the side of the bracket 120 away from the first thermal insulation component 200 and is provided with a second sub-hole 131. The first pressure relief hole 110 further includes a second sub-hole 131, which is arranged opposite to the first sub-hole 121. The projection area of ​​the second sub-hole 131 on the horizontal plane is greater than or equal to the projection area of ​​the corresponding first sub-hole 121 on the horizontal plane.

[0019] Specifically, the tray 130 is an aluminum plate to ensure the strength of the support assembly 100. The bracket 120 has the function of insulation and heat preservation. The bracket 120 can increase the distance between the tray 130 and the battery cell 300, thereby increasing the creepage distance and ensuring the safety performance of the battery pack 10.

[0020] 1 and 5 , the support assembly 100 further includes a box 140, the tray 130 is mounted on the box 140, and the bracket 120 is attached to the tray 130. It is understood that the box 140 can be integrally formed with the tray 130 and / or the bracket 120.

[0021] In one embodiment, the first thermal insulation member 200 is made of mica and can be bonded to the side of the bracket 120 facing away from the tray 130, thereby providing insulation and heat protection for the bracket 120 and the tray 130. In Figure 2, there are multiple first thermal insulation members 200, each of which covers a corresponding first sub-hole 121 to seal the corresponding first sub-hole 121. It is understood that in other embodiments, the first thermal insulation member 200 can also be made of other thermally insulating materials, and the first thermal insulation member 200 can also be integrally formed, that is, the first thermal insulation member 200 is a plate.

[0022] In other embodiments, the first thermal insulation member 200 may also be designed with an open hole, and the first sub-hole 121 may be sealed by the second thermal insulation member 900 .

[0023] In one embodiment, as shown in Figure 6, each first thermal insulation member 200 includes a valve opening portion 210 and an annular portion 220. The valve opening portion 210 is arranged opposite to the first sub-hole 121, and the annular portion 220 is respectively connected to the outer periphery of the valve opening portion 210 and the bracket 120, and the thickness of the valve opening portion 210 is less than the thickness of the annular portion 220. This can not only reduce the production cost of the battery pack 10, but also make it easier for high-temperature and high-pressure materials ejected when a certain battery cell 300 suffers thermal runaway to penetrate the valve opening portion 210.

[0024] Specifically, the ratio of the thickness of the valve opening portion 210 to the thickness of the annular portion 220 is greater than or equal to 0.2 and less than or equal to 0.5. In a specific implementation, the thickness of the valve opening portion 210 is 0.1 mm, and the thickness of the annular portion 220 is greater than or equal to 0.2 mm and less than or equal to 0.5 mm.

[0025] In one embodiment, the projected area of ​​each valve opening portion 210 on the horizontal plane is greater than or equal to 80% of the projected area of ​​the corresponding battery cell 300 on the horizontal plane and less than or equal to the projected area of ​​the corresponding first sub-hole 121 on the horizontal plane, and the projected area of ​​the first sub-hole 121 on the horizontal plane is less than or equal to the projected area of ​​the second sub-hole 131 on the horizontal plane, providing a control for the projected areas of the valve opening portion 210, the first sub-hole 121 and the second sub-hole 131 on the horizontal plane, thereby ensuring a redundant design and improving the protection reliability of the first thermal insulation component 200.

[0026] In one embodiment, as shown in FIG6 , the bracket 120 is provided with a first extension portion 122 extending toward the second sub-hole 131 on the outer periphery of each first sub-hole 121. The first extension portion 122 can be inserted into the second sub-hole 131 and abut against the sidewall of the second sub-hole 131, or can be spaced apart from the sidewall of the second sub-hole 131. The extension length of the first extension portion 122 is equal to the thickness of the tray 130. That is, the side of the first extension portion 122 facing away from the first thermal insulation member 200 is flush with the side of the tray 130 facing away from the first thermal insulation member 200. The first extension portion 122 not only facilitates installation of the bracket 120 on the tray 130 (simply inserting the first extension portion 122 into the second sub-hole 131 directly aligns the first and second sub-holes 121, 131), but also provides insulation and thermal protection for the tray 130 and increases creepage distance, thereby ensuring the safety of the battery pack 10.

[0027] In other embodiments, the first thermal insulation member 200 may also be provided with a second extension portion (not shown) extending toward the first sub-hole 121 and the second sub-hole 131 in sequence. The second extension portion may provide insulation and heat protection for the bracket 120 and the tray 130 .

[0028] In one embodiment, an explosion-proof valve 310 is provided at one end of each battery cell 300 close to the valve opening portion 210, and the explosion-proof valve 310 is arranged opposite to the valve opening portion 210. When a battery cell 300 suffers thermal runaway under extreme working conditions, the high-temperature and high-pressure material generated inside the battery cell 300 will rush open the explosion-proof valve 310 to release the pressure in time, and the high-temperature and high-pressure material ejected from the battery cell 300 will break through the corresponding valve opening portion 210 and flow out through the first sub-hole 121 and the second sub-hole 131 in sequence, and the annular portion 220 can prevent the high-temperature and high-pressure material ejected from the battery cell 300 from flowing to the adjacent good battery cell 300, and the remaining intact valve opening portions 210 can also prevent the high-temperature and high-pressure material from reverse heat transfer or flowing into the good battery cell 300.

[0029] In one embodiment, the second thermal insulator 900 is a plate made of mica material. It is bonded to the side of the tray 130 facing away from the support 120. The high-temperature, high-pressure material ejected from the uncontrolled battery cell 300 will sequentially penetrate the first thermal insulator 200 and the second thermal insulator 900 before flowing out. The second thermal insulator 900 prevents the high-temperature, high-pressure material from conducting heat backward or flowing into the intact battery cell 300, while also providing insulation and protection for the support 120 and tray 130. In other embodiments, the second thermal insulator 900 can be made of other insulating materials.

[0030] In one embodiment, the second thermal insulation member 900 is provided with a plurality of second pressure relief holes 910. Each second pressure relief hole 910 is connected to a corresponding second sub-hole 131 and is disposed directly opposite the corresponding second sub-hole 131. Each second pressure relief hole 910 should be larger than or equal to the horizontal projection area of ​​the first sub-hole 121 and smaller than or equal to the area of ​​the second sub-hole 131. The presence of the second pressure relief holes 910 prevents the second thermal insulation member 900 from being detached from the support assembly 100 when high-temperature, high-pressure materials impact the second thermal insulation member 900.

[0031] In other embodiments, the second thermal insulation member 900 may also be provided with multiple weakened portions (not shown), each of which is positioned directly opposite a corresponding second sub-hole 131, and the projected area of ​​each weakened portion on a horizontal plane is greater than or equal to the projected area of ​​the corresponding first sub-hole 121 on the horizontal plane, and less than or equal to the projected area of ​​the corresponding second sub-hole 131 on the horizontal plane. The thickness of the weakened portions is thinner than the thickness of other portions of the second thermal insulation member 900 (non-weakened portions). This weakened portion can reduce production costs and is more easily penetrated by high-temperature, high-pressure materials, thereby preventing the second thermal insulation member 900 from separating from the tray 130 under the impact of high-temperature, high-pressure materials.

[0032] In one embodiment, as shown in Figures 2, 3, and 6, the battery pack 10 further includes a rubber stopper 240. The rubber stopper 240 is disposed on a side of the first thermal insulation member 200 facing away from the bracket 120 and is formed with a plurality of through-holes 241. Each through-hole 241 is disposed directly opposite a corresponding battery cell 300 and a corresponding first sub-hole 121. The projected area of ​​each through-hole 241 on a horizontal plane is greater than or equal to the projected area of ​​the valve opening portion 210 on a horizontal plane. It is understood that in other embodiments, the rubber stopper 240 can be integrally formed with the first thermal insulation member 200, that is, the rubber stopper 240 can be integrally formed with the annular portion 220, thereby reducing the assembly steps of the battery pack 10 and improving production efficiency.

[0033] The rubber stopper 240 is a plate made of rubber-blocking foam and is used to contact the end faces of the battery cells 300. Its thickness depends on the flatness of the support assembly 100 and the height of the battery cell assembly stack. In practice, the thickness of the rubber stopper 240 is greater than or equal to 1 mm. This prevents glue from flowing into the explosion-proof valve 310 on the battery cells 300 and also ensures that the battery cells 300 are spaced apart from the first thermal insulation member 200, ensuring smooth opening of the battery cells 300.

[0034] In one embodiment, as shown in FIG. 2 , the battery pack 10 further includes a structural adhesive 250 , which is connected to a side of the adhesive stopper 240 facing away from the first thermal insulation member 200 , so as to bond the plurality of battery cells 300 to the adhesive stopper 240 .

[0035] In one embodiment, as shown in Figures 4 and 6, the structural adhesive 250 is formed with a plurality of mounting holes 251, and the mounting holes 251 are arranged opposite to the through holes 241. A battery cell 300 is bonded in each mounting hole 251, and a clamping portion 252 is formed on the side wall of each mounting hole 251. The clamping portion 252 is used to clamp with the side wall of the battery cell 300, thereby making the battery cell 300 more stable after installation.

[0036] In one embodiment, the battery pack 10 further includes a bottom guard plate 400, which is disposed on the side of the tray 130 facing away from the battery cells 300. A pressure relief chamber 600 is formed between the tray 130 and the bottom guard plate 400, and a second thermal insulator 900 is located within the pressure relief chamber 600. When a battery cell 300 experiences thermal runaway, the high-temperature, high-pressure material ejected from it penetrates the corresponding first thermal insulator 200 and / or second thermal insulator 900 and flows into the pressure relief chamber 600. The remaining first thermal insulator 200 and / or second thermal insulator 900, which seals the first pressure relief hole 110, prevents the high-temperature, high-pressure material in the pressure relief chamber 600 from conducting reverse heat transfer or flowing into intact battery cells 300, thereby preventing heat spread in the battery pack 10.

[0037] In one embodiment, the bottom guard plate 400 is detachably mounted on the box body 140 , or the bottom guard plate 400 and the box body 140 are integrally formed.

[0038] In one embodiment, as shown in FIG2 , the battery pack 10 further includes a plurality of support members 800 , which are spaced apart between the tray 130 and the bottom guard plate 400 and are respectively connected to the tray 130 and the bottom guard plate 400. The plurality of support members 800 are used to enhance the overall rigidity of the battery pack 10 , thereby ensuring the height of the pressure relief chamber 600 and preventing the bracket 120 and tray 130 from collapsing toward the bottom guard plate 400 due to the weight of the battery cells 300.

[0039] The support member 800 may be directly connected to the tray 130 through the second thermal insulation member 900 , or may be indirectly connected to the tray 130 through the second thermal insulation member 900 .

[0040] In a specific implementation, the support member 800 is a buffer block, which is respectively bonded to the tray 130 and the bottom guard plate 400. The support member 800 can also be a convex bump on the bottom guard plate 400 with a buffer material or a convex bump on the tray 130 with a buffer material, that is, the support member 800 is integrally formed with the tray 130 or the bottom guard plate 400.

[0041] The height of the support member 800 is greater than or equal to the height of the pressure relief chamber 600. The supporting force provided by the support member 800 should be greater than the gravity of the battery cell 300 assembly, and the projection of the support member 800 on the horizontal plane does not coincide with the projection of the second sub-hole 131 on the horizontal plane, so as to avoid the support member 800 hindering the high-temperature and high-pressure material from flowing from the second sub-hole 131 into the pressure relief chamber 600.

[0042] In one embodiment, as shown in Figures 2 and 6, the battery pack 10 further includes a third thermal insulator 500. The third thermal insulator 500 is a plate made of mica material, which is bonded to the side of the bottom guard plate 400 near the tray 130 and is located within the pressure relief cavity 600. The compressive strength of the third thermal insulator 500 is greater than the compressive strength of the first thermal insulator 200, thereby ensuring that the high-temperature and high-pressure substances within the pressure relief cavity 600 do not penetrate the bottom guard plate 400. In other embodiments, the third thermal insulator 500 can also be made of other thermally insulating materials.

[0043] In one embodiment, the thickness of the third thermal insulation member 500 is greater than or equal to 0.50 mm and less than or equal to 2.00 mm to control the production cost of the battery pack 10 .

[0044] In one embodiment, the projected area of ​​the third thermal insulation member 500 on the bottom guard plate 400 should be greater than or equal to 110% of the projected area of ​​the battery cell 300 assembly on the bottom guard plate 400 to ensure the safety performance of the battery pack 10.

[0045] Compared with the related art, the battery pack 10 provided in the present application uses the first thermal insulation member 200 and the second thermal insulation member 900 to insulate and protect the support assembly 100, and the first thermal insulation member 200 and / or the second thermal insulation member 900 seal the first pressure relief hole 110. When a certain battery cell 300 experiences thermal runaway, the high-temperature and high-pressure material ejected breaks through the corresponding first thermal insulation member 200 and / or the second thermal insulation member 900. The remaining first thermal insulation member 200 and / or the second thermal insulation member 900 that seals the first pressure relief hole 110 can prevent the high-temperature and high-pressure material from reversely transferring heat or flowing into the good battery cell 300, thereby avoiding the phenomenon of heat spread in the battery pack 10.

Claims

1. A battery pack, comprising: A support assembly is provided with a plurality of first pressure relief holes; a first thermal insulation member connected to the support assembly; A plurality of battery cells are respectively arranged on a side of the first heat insulating member away from the supporting assembly, and the explosion-proof valve of each of the battery cells is arranged directly opposite to the corresponding first pressure relief hole; A second thermal insulation member is connected to a side of the support assembly facing away from the first thermal insulation member, and at least one of the first thermal insulation member and the second thermal insulation member seals the plurality of first pressure relief holes.

2. The battery pack according to claim 1, wherein: The support assembly includes a bracket, the bracket is provided with a plurality of first sub-holes, the first pressure relief hole includes the first sub-holes, and the first heat insulating member is attached to the bracket.

3. The battery pack according to claim 2, wherein: The first thermal insulation member seals a plurality of the first sub-holes. The number of the first thermal insulation members is plural, and each of the first thermal insulation members includes a valve opening portion and an annular portion. The valve opening portion is arranged opposite to the corresponding first sub-hole, and the annular portion is respectively connected to the outer periphery of the valve opening portion and the bracket. The thickness of the valve opening portion is less than the thickness of the annular portion.

4. The battery pack according to claim 3, wherein: A ratio of a thickness of the valve opening portion to a thickness of the annular portion is greater than or equal to 0.2 and less than or equal to 0.

5.

5. The battery pack according to claim 3, wherein: The projection area of ​​each of the valve opening portions on the horizontal plane is greater than or equal to 80% of the projection area of ​​the corresponding battery cell on the horizontal plane and less than or equal to the projection area of ​​the corresponding first sub-hole on the horizontal plane.

6. The battery pack according to claim 2, wherein: The support assembly also includes a tray, which is arranged on the side of the bracket away from the first thermal insulation member and has a plurality of second sub-holes. The first pressure relief hole also includes the second sub-hole, which is arranged opposite to the corresponding first sub-hole. The projection area of ​​each second sub-hole on the horizontal plane is greater than or equal to the projection area of ​​the corresponding first sub-hole on the horizontal plane. The second thermal insulation member is attached to the side of the tray away from the bracket.

7. The battery pack according to claim 6, wherein: The bracket is provided with a first extending portion extending toward the second sub-hole, or the first heat insulating member is provided with a second extending portion extending toward the first sub-hole and the second sub-hole in sequence.

8. The battery pack according to claim 6, wherein: The second thermal insulation component is provided with a plurality of second pressure relief holes, each of which is arranged opposite to the corresponding second sub-hole, and the projection area of ​​each of the second pressure relief holes on the horizontal plane is greater than or equal to the projection area of ​​the corresponding first sub-hole on the horizontal plane and less than or equal to the projection area of ​​the corresponding second sub-hole on the horizontal plane.

9. The battery pack according to claim 6, wherein: The second thermal insulation component is provided with multiple weak parts, each of the weak parts is arranged directly opposite to the corresponding second sub-hole, and the projection area of ​​each weak part on the horizontal plane is greater than or equal to the projection area of ​​the corresponding first sub-hole on the horizontal plane and less than or equal to the projection area of ​​the corresponding second sub-hole on the horizontal plane.

10. The battery pack according to any one of claims 1-9, further comprising a rubber stopper, wherein the rubber stopper is attached to a side of the first heat insulating member away from the supporting assembly and is used to contact end faces of the plurality of battery cells, wherein the rubber stopper is formed with a plurality of via holes, and each of the via holes is respectively arranged opposite to the corresponding battery cell and the corresponding first pressure relief hole.

11. According to the battery pack of claim 10, the battery pack also includes structural adhesive, the structural adhesive is connected to the side of the adhesive stopper facing away from the first thermal insulation component, the structural adhesive forms a plurality of mounting holes, the battery cells are installed in the corresponding mounting holes, and a clamping portion is provided on the side wall of each mounting hole, and the clamping portion is used to clamp with the side wall of the battery cell.

12. The battery pack according to any one of claims 1-9, further comprising a bottom guard plate, wherein the bottom guard plate is arranged on a side of the support assembly away from the battery cell, and a pressure relief chamber is formed between the bottom guard plate and the support assembly. 13 . The battery pack according to claim 12 , further comprising a plurality of support members, wherein the plurality of support members are spaced apart and arranged between the support assembly and the bottom guard plate.

14. The battery pack according to claim 13, wherein: The support member is a buffer block, and the buffer block is respectively bonded to the support assembly and the bottom guard plate.

15. The battery pack according to claim 12, further comprising a third heat insulating member, which is disposed on a side of the bottom guard plate close to the support assembly and is located in the pressure relief chamber.

16. The battery pack according to claim 15, wherein: The projection area of ​​the third thermal insulation component on the bottom guard plate is greater than or equal to 110% of the projection area of ​​the plurality of battery cells on the bottom guard plate.

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