battery pack

Abstract

The present application provides a battery pack comprising a support assembly, a first insulating member, a plurality of battery cells, and a second insulating member, wherein a plurality of first pressure release holes are provided in the support assembly; the first insulating member is connected to the support assembly; a plurality of battery cells are installed on one side facing away from the first insulating member and the support assembly, and the explosion-proof valves of each battery cell are all installed facing the corresponding first pressure release holes; the second insulating member is connected to one side facing away from the support assembly and the first insulating member and at least one of the first insulating member and the second insulating member seals the plurality of first pressure release holes.

Description

Technology Field

[0001] This application claims priority to a Chinese patent application filed with the China Intellectual Property Administration on November 2, 2023, with application number 2023229718151, and the entire contents of the application are incorporated by reference into this application.

[0002] This application relates to the field of battery technology, specifically to battery packs. Background Technology

[0003] In recent years, the new energy vehicle market has been continuously expanding, and sales of new energy vehicles have been increasing year by year. As a core component of new energy vehicles, the battery system has a significant impact on the safety and performance limits of the vehicle.

[0004] To ensure the safety of the battery pack, explosion-proof valves are typically installed at the ends of the battery cells, and if thermal runaway occurs in any battery cell under extreme operating conditions, the high-temperature, high-pressure material generated inside the cell ruptures the explosion-proof valve, releasing the pressure in a timely manner. The problem to be solved

[0005] High-temperature, high-pressure substances ejected due to thermal runaway in battery cells are prone to diffusing to other healthy battery cells, causing short circuits between them and resulting in the spread of heat. means of solving the problem

[0006] The present application provides a battery pack comprising a support assembly, a first insulating member, a plurality of battery cells, and a second insulating member, wherein a plurality of first pressure relief holes are provided in the support assembly; the first insulating member is connected to the support assembly; a plurality of battery cells are each installed on one side facing away from the first insulating member of the support assembly, and the explosion-proof valve of each battery cell is installed facing a corresponding first pressure relief hole; a second insulating member is connected to one side facing away from the first insulating member of the support assembly, and at least one of the first insulating member and the second insulating member seals the plurality of first pressure relief holes. Effects of the invention

[0007] The beneficial effects of the battery pack provided in this application are as follows. The battery pack seals a first pressure release hole with a first insulating member and provides insulating protection for the support assembly. When a thermal runaway occurs in a battery cell, the high-temperature, high-pressure material ejected ruptures the first insulating member and flows into the pressure release chamber through the corresponding first pressure release hole. Subsequently, the remaining first insulating member sealing the first pressure release hole can prevent the high-temperature, high-pressure material within the pressure release chamber from transferring heat in the reverse direction or flowing into the good battery cell. At the same time, the second insulating member can ensure that the high-temperature, high-pressure material within the pressure release chamber does not rupture the bottom protection plate, thereby preventing the high-temperature, high-pressure material within the pressure release chamber from overflowing and damaging the bottom protection plate. This prevents a short circuit between the good battery cells and avoids the phenomenon of heat spreading within the battery pack. Brief explanation of the drawing

[0008] FIG. 1 is a schematic diagram of the perspective structure of a battery pack provided in one embodiment of the present application. FIG. 2 is a schematic diagram of the exploded structure of a battery pack provided in one embodiment of the present application. Figure 3 is an enlarged view of position B in Figure 2. Figure 4 is an enlarged view of position C in Figure 2. Figure 5 is a schematic diagram of the cross-sectional structure along line AA in Figure 1. Figure 6 is an enlarged view of position D in Figure 5. Specific details for implementing the invention

[0009] Referring to FIGS. 2 and FIGS. 6, an embodiment of the present application provides a battery pack (10), wherein the battery pack (10) comprises a support assembly (100), a first insulating member (200), a plurality of battery cells (300), and a second insulating member (900), wherein a plurality of first pressure relief holes (110) are provided in the support assembly (100), the first insulating member (200) is connected to the support assembly (100), and each of the plurality of battery cells (300) is installed on one side facing away from the support assembly (100), and each explosion-proof valve (310) of each battery cell (300) is installed facing the corresponding first pressure relief hole (110), and the second insulating member (900) is connected to one side facing away from the support assembly (100), and at least one of the first insulating member (200) and the second insulating member (900) One seals a plurality of first pressure release holes (110). Compared to related technology, the battery pack (10) provided in this application provides insulation insulation protection for a support assembly (100) with a first insulation member (200) and a second insulation member (900), and by having the first insulation member (200) and / or the second insulation member (900) seal the first pressure release hole (110), the high-temperature, high-pressure material ejected when a thermal runaway occurs in any battery cell (300) can rupture the corresponding first insulation member (200) and / or the second insulation member (900), and the remaining first insulation member (200) and / or the second insulation member (900) sealing the first pressure release hole (110) can prevent the high-temperature, high-pressure material from transferring heat in the reverse direction or flowing into the good battery cell (300), thereby avoiding the phenomenon of heat spreading in the battery pack (10).

[0010] For example, as shown in FIG. 2, a support assembly (100) includes a rack (120), and a plurality of first subholes (121) are provided in the rack (120), and a first pressure relief hole (110) includes the first subholes (121), and a first insulating member (200) is in close contact with the rack (120) to seal the plurality of first subholes (121).

[0011] In one embodiment, the rack (120) is a plastic plate, and a plurality of first subholes (121) are installed on the rack (120) at spaced intervals to improve space utilization.

[0012] In one embodiment, the support assembly (100) further includes a tray (130), the tray (130) is in close contact with one side facing away from the first insulation member (200) and has a second subhole (131), the first pressure relief hole (110) further includes the second subhole (131), the second subhole (131) is installed facing the first subhole (121), and the horizontal projection area of ​​the second subhole (131) is greater than or equal to the horizontal projection area of ​​the corresponding first subhole (121).

[0013] Specifically, the tray (130) is an aluminum plate and secures the strength of the support assembly (100). The rack (120) has an insulating thermal effect, and the rack (120) can increase the distance between the tray (130) and the battery cell (300), thereby increasing the creepage distance and securing the safety performance of the battery pack (10).

[0014] In one embodiment, as shown in FIGS. 1 and FIGS. 5, the support assembly (100) further comprises a box body (140), a tray (130) is mounted on the box body (140), and a rack (120) is in close contact with the tray (130). It can be understood that the box body (140) may be integrally molded with the tray (130) and / or the rack (120).

[0015] In one embodiment, the first insulating member (200) is made of mica material and can be attached to one side facing away from the rack (120) and the tray (130), thereby providing insulating protection for the rack (120) and the tray (130). In FIG. 2, the number of first insulating members (200) is multiple, and each first insulating member (200) is covered and installed in a corresponding first subhole (121) to seal the corresponding first subhole (121). In another embodiment, the first insulating member (200) may be made of a different insulating material, or the first insulating member (200) may be integrally molded, that is, it can be understood that the first insulating member (200) is a single plate.

[0016] In another embodiment, the first insulating member (200) may be designed as an opening, and the first subhole (121) is sealed with the second insulating member (900).

[0017] In one embodiment, as shown in FIG. 6, each first insulating member (200) includes a valve opening (210) and an annular portion (220), the valve opening (210) is installed facing the first subhole (121), and the annular portion (220) is connected to the outer circumference of the valve opening (210) and the rack (120), and the thickness of the valve opening (210) is smaller than the thickness of the annular portion (220), thereby not only reducing the production cost of the battery pack (10), but also allowing the high-temperature, high-pressure material ejected when thermal runaway occurs in any battery cell (300) to rupture the valve opening (210) more easily.

[0018] Specifically, the ratio of the thickness of the valve opening (210) to the thickness of the annular portion (220) is 0.2 or more and 0.5 or less. In a specific embodiment, the thickness of the valve opening (210) is 0.1 mm, and the thickness of the annular portion (220) is 0.2 mm or more and 0.5 mm or less.

[0019] In one embodiment, the horizontal projection area of ​​each valve opening (210) is 80% or more of the horizontal projection area of ​​the corresponding battery cell (300) and is smaller than or equal to the horizontal projection area of ​​the corresponding first subhole (121), while the horizontal projection area of ​​the first subhole (121) is smaller than or equal to the horizontal projection area of ​​the second subhole (131), thereby controlling the horizontal projection areas of the valve opening (210), the first subhole (121), and the second subhole (131), thereby securing multiple designs and improving the protection reliability of the first insulation member (200).

[0020] In one embodiment, as shown in FIG. 6, a first extension (122) extending toward a second subhole (131) is installed on the outer periphery of each first subhole (121) of the rack (120), and the first extension (122) is inserted into the second subhole (131) and may be in contact with the side wall of the second subhole (131) or may be installed spaced apart from the side wall of the second subhole (131), and the extension length of the first extension (122) is equal to the thickness of the tray (130), that is, the height of the side of the first extension (122) facing away from the first insulation member (200) matches the height of the side of the tray (130) facing away from the first insulation member (200). The first extension part (122) can make it more convenient when the rack (120) is mounted on the tray (130) (by simply inserting the first extension part (122) into the second sub-hole (131) so that the first sub-hole (121) can be installed facing the second sub-hole (131)), and also allows for insulation thermal protection for the tray (130), increases the creepage distance, and ensures the safety performance of the battery pack (10).

[0021] In another embodiment, a second extension (not shown) extending sequentially toward a first subhole (121) and a second subhole (131) may be installed in the first insulation member (200), and the second extension may provide insulation insulation protection for the rack (120) and the tray (130).

[0022] In one embodiment, an explosion-proof valve (310) is installed at one end where each battery cell (300) approaches the valve opening (210), and the explosion-proof valve (310) is installed facing the valve opening (210). When a thermal runaway occurs in any battery cell (300) under extreme operating conditions, the high-temperature, high-pressure material generated inside the battery cell (300) penetrates the explosion-proof valve (310) and releases pressure in time. The high-temperature, high-pressure material ejected from the battery cell (300) ruptures the corresponding valve opening (210) and flows out sequentially through the first sub-hole (121) and the second sub-hole (131), while the annular portion (220) can prevent the high-temperature, high-pressure material ejected from the battery cell (300) from flowing into the adjacent good battery cell (300), and the remaining intact valve opening (210) prevents the high-temperature, high-pressure material from transferring heat in the reverse direction or to the good battery cell (300). It can also prevent inflow.

[0023] In one embodiment, the second insulating member (900) is a plate made of mica material, and the second insulating member (900) is attached to one side of the tray (130) facing away from the rack (120), and high-temperature, high-pressure material ejected from a thermally runaway battery cell (300) sequentially ruptures the first insulating member (200) and the second insulating member (900) and then leaks out. The second insulating member (900) can not only prevent the high-temperature, high-pressure material from transferring heat in the reverse direction or entering the good battery cell (300), but also provide insulating protection for the rack (120) and the tray (130). In another embodiment, the second insulating member (900) may be made of a different insulating material.

[0024] In one embodiment, a plurality of second pressure release holes (910) are provided in the second insulation member (900), and each second pressure release hole (910) is connected to a corresponding second subhole (131), and each second pressure release hole (910) is installed facing the corresponding second subhole (131), and each second pressure release hole (910) must be larger than or equal to the horizontal plane projected area of ​​the first subhole (121) and smaller than or equal to the area of ​​the second subhole (131). The presence of the second pressure release holes (910) can prevent the second insulation member (900) from detaching from the support assembly (100) when a high-temperature, high-pressure material impacts the second insulation member (900).

[0025] In another embodiment, a plurality of vulnerable parts (not shown) may be provided in the second insulation member (900), and each vulnerable part is installed facing the corresponding second sub-hole (131), and the horizontal projection area of ​​each vulnerable part is greater than or equal to the horizontal projection area of ​​the corresponding first sub-hole (121) and less than or equal to the horizontal projection area of ​​the corresponding second sub-hole (131). Here, the thickness of the vulnerable part location is smaller than the thickness of other parts (non-vulnerable parts) on the second insulation member (900), and the vulnerable part can not only reduce production costs but also rupture more easily by high-temperature, high-pressure material, thereby preventing the second insulation member (900) from detaching from the tray (130) under the impact of high-temperature, high-pressure material.

[0026] In one embodiment, as shown in FIGS. 2, 3 and 6, the battery pack (10) further comprises an adhesive blocking member (240), wherein the adhesive blocking member (240) is installed on one side facing away from the rack (120) and has a plurality of through holes (241) formed therein, each through hole (241) is installed facing a corresponding battery cell (300) and a corresponding first sub-hole (121), and the horizontal projected area of ​​each through hole (241) is greater than or equal to the horizontal projected area of ​​the valve opening (210). In another embodiment, the adhesive blocking member (240) may be integrally molded with the first insulation member (200), that is, the adhesive blocking member (240) may be integrally molded with the annular portion (220), thereby reducing the assembly steps of the battery pack (10) and improving production efficiency.

[0027] The adhesive blocking member (240) is a plate made of an adhesive blocking foam material and is used to contact the cross-section of the battery cell (300), and its thickness is determined by the planar view of the support assembly (100) and the stack height of the battery cell assembly. In a specific embodiment, the thickness of the adhesive blocking member (240) is 1 mm or more, and thus the adhesive blocking member (240) not only performs an adhesive blocking function but also prevents the adhesive from flowing into the explosion-proof valve (310) on the battery cell (300), and also ensures that the battery cell (300) and the first insulation member (200) are installed apart, thereby ensuring the smooth development of the battery cell (300).

[0028] In one embodiment, as shown in FIG. 2, the battery pack (10) further comprises a structural adhesive (250), and the structural adhesive (250) is connected to one side facing away from the first insulating member (200) and is used to bond a plurality of battery cells (300) to the adhesive blocking member (240).

[0029] In one embodiment, as shown in FIGS. 4 and 6, a plurality of mounting holes (251) are provided in a structural adhesive (250), and the mounting holes (251) are installed facing through holes (241), and each mounting hole (251) has a battery cell (300) attached to it, and each mounting hole (251) has a connecting part (252) formed on its side wall, and the connecting part (252) is used to connect to the side wall of the battery cell (300), thereby making the battery cell (300) more stable after mounting.

[0030] In one embodiment, the battery pack (10) further includes a bottom protection plate (400), the bottom protection plate (400) is installed on one side facing away from the battery cell (300), a pressure relief chamber (600) is formed between the tray (130) and the bottom protection plate (400), and a second insulation member (900) is located within the pressure relief chamber (600). When a thermal runaway occurs in a battery cell (300), the high-temperature, high-pressure material ejected ruptures the corresponding first insulation member (200) and / or second insulation member (900) and flows into the pressure release chamber (600), and the remaining first insulation member (200) and / or second insulation member (900) sealing the first pressure release hole (110) can prevent the high-temperature, high-pressure material in the pressure release chamber (600) from transferring heat in the reverse direction or flowing into the good battery cell (300), thereby preventing the phenomenon of heat spreading in the battery pack (10).

[0031] In one embodiment, the bottom protection plate (400) is detachably mounted to the box body (140), or the bottom protection plate (400) and the box body (140) are formed integrally.

[0032] In one embodiment, as shown in FIG. 2, the battery pack (10) further comprises a plurality of support members (800), and the plurality of support members (800) are spaced apart between the tray (130) and the bottom protection plate (400) and are each connected to the tray (130) and the bottom protection plate (400). The plurality of support members (800) are used to improve the overall strength of the battery pack (10), secure the height of the pressure release chamber (600), and prevent the rack (120) and the tray (130) from sinking in the direction approaching the bottom protection plate (400) due to the gravity of the battery cell (300).

[0033] The support member (800) can be connected directly to the tray (130) by penetrating the second insulation member (900), or it can be connected indirectly to the tray (130) through the second insulation member (900).

[0034] In a specific embodiment, the support member (800) is a cushioning block, and the cushioning block is attached to the tray (130) and the bottom protection plate (400), respectively. The support member (800) may be a convex body with cushioning material added to the bottom protection plate (400) or a convex body with cushioning material added to the tray (130), in other words, the support member (800) and the tray (130) or the bottom protection plate (400) are formed integrally.

[0035] The height of the support member (800) is greater than or equal to the height of the pressure release chamber (600), and the support force provided by the support member (800) must be greater than the gravity of the battery cell (300) assembly, and the horizontal plane projection of the support member (800) does not overlap with the horizontal plane projection of the second subhole (131), and the support member (800) avoids hindering high temperature and high pressure material from flowing into the pressure release chamber (600) from the second subhole (131).

[0036] In one embodiment, as shown in FIGS. 2 and FIGS. 6, the battery pack (10) further comprises a third insulating member (500), the third insulating member (500) being a plate made of mica material and coupled to one side where the bottom protection plate (400) approaches the tray (130) and located within the pressure release chamber (600). The compressive strength of the third insulating member (500) is greater than the compressive strength of the first insulating member (200), thereby ensuring that the high-temperature, high-pressure material within the pressure release chamber (600) does not rupture the bottom protection plate (400). In another embodiment, the third insulating member (500) may be made of a different insulating material.

[0037] In one embodiment, the thickness of the third insulating member (500) is 0.50 mm or more and 2.00 mm or less, thereby reducing the production cost of the battery pack (10).

[0038] In one embodiment, the projected area of ​​the bottom protection plate (400) of the third insulation member (500) must be at least 110% of the projected area of ​​the bottom protection plate (400) of the battery cell (300) assembly, thereby ensuring the safety performance of the battery pack (10).

[0039] Compared to related technologies, the battery pack (10) provided in the present application provides insulation insulation protection for a support assembly (100) with a first insulation member (200) and a second insulation member (900), and by having the first insulation member (200) and / or the second insulation member (900) seal the first pressure release hole (110), the high-temperature, high-pressure material ejected when a thermal runaway occurs in any battery cell (300) can rupture the corresponding first insulation member (200) and / or the second insulation member (900), and the remaining first insulation member (200) and / or the second insulation member (900) sealing the first pressure release hole (110) can prevent the high-temperature, high-pressure material from transferring heat in the reverse direction or flowing into the good battery cell (300), thereby avoiding the phenomenon of heat spreading in the battery pack (10). Explanation of the symbols

[0040] 10: Battery pack 100: Support assembly 110: First pressure relief hole 120: Rack 121: 1st Subhole 122: 1st extension 130: Tray 131: 2nd Subhole 140: Box 200: First insulating member 210: Valve opening 220: Ring part 240: Adhesive blocking member 241: Through hole 250: Structural adhesive 251: Mounting hole 252: Stiffness connection 300: Battery cell 310: Explosion-proof valve 400: Bottom protection plate 500: Third insulation member 600: Pressure relief chamber 800: Support member 900: Second insulation member 910: Second pressure relief hole

Claims

Claim 1 A battery pack comprising a support assembly, a first insulating member, a plurality of battery cells, and a second insulating member, wherein a plurality of first pressure release holes are provided in the support assembly; the first insulating member is connected to the support assembly; each of the plurality of battery cells is installed on one side facing away from the first insulating member and each of the explosion-proof valves of the respective battery cells is installed facing the corresponding first pressure release holes; the second insulating member is connected to one side facing away from the support assembly and at least one of the first insulating member and the second insulating member seals the plurality of first pressure release holes. Claim 2 A battery pack according to claim 1, wherein the support assembly includes a rack, and the rack has a plurality of first subholes provided, and the first pressure relief hole includes the first subhole, and the first insulating member is in close contact with the rack. Claim 3 In paragraph 2, the first insulating member seals a plurality of the first subholes, and the number of the first insulating members is plurality, and each of the first insulating members includes a valve opening and an annular portion, the valve opening is installed facing the corresponding first subhole, and the annular portion is connected to the outer circumference of the valve opening and the rack, and the thickness of the valve opening is smaller than the thickness of the annular portion of the battery pack. Claim 4 A battery pack according to paragraph 3, wherein the ratio of the thickness of the valve opening to the thickness of the annular portion is 0.2 or more and 0.5 or less. Claim 5 In paragraph 3, the horizontal plane projected area of ​​each of the valve openings is greater than or equal to 80% of the horizontal plane projected area of ​​the corresponding battery cell and is smaller than or equal to the horizontal plane projected area of ​​the corresponding first subhole. Claim 6 In paragraph 2, the support assembly further comprises a tray, wherein the tray is installed on one side facing the rack and has a plurality of second subholes, and the first pressure release hole further comprises the second subholes, and the second subholes are installed facing the corresponding first subholes, and the horizontal projection area of ​​each of the second subholes is greater than or equal to the horizontal projection area of ​​the corresponding first subhole in the horizontal plane, and the second insulation member is a battery pack that is in close contact with the tray on one side facing the rack. Claim 7 A pattern pack according to claim 6, wherein a first extension extending toward the second subhole is installed in the rack, or a second extension extending toward the first subhole and the second subhole is installed sequentially in the first insulating member. Claim 8 A battery pack according to claim 6, wherein a plurality of second pressure release holes are provided in the second insulating member, and each of the second pressure release holes is installed facing the corresponding second sub-hole, and the horizontal plane projected area of ​​each of the second pressure release holes is greater than or equal to the horizontal plane projected area of ​​the corresponding first sub-hole and is smaller than or equal to the horizontal plane projected area of ​​the corresponding second sub-hole. Claim 9 A battery pack according to claim 6, wherein a plurality of vulnerable parts are provided in the second insulating member, each of which is installed facing the corresponding second subhole, and the horizontal projection area of ​​each of which is greater than or equal to the horizontal projection area of ​​the corresponding first subhole and less than or equal to the horizontal projection area of ​​the corresponding second subhole. Claim 10 In any one of claims 1 to 9, the battery pack further comprises an adhesive blocking member, wherein the adhesive blocking member is used to be in close contact with one side facing away from the support assembly and to be in contact with the cross-section of a plurality of battery cells, and wherein a plurality of through holes are formed in the adhesive blocking member, and each of the through holes is installed facing the corresponding battery cell and the corresponding first pressure release hole. Claim 11 In claim 10, the battery pack further comprises a structural adhesive, wherein the structural adhesive is connected to one side facing away from the first insulating member, and the structural adhesive has a plurality of mounting holes provided in the structural adhesive, and the battery cell is mounted within the corresponding mounting hole, and a locking connection is provided on the side wall of each mounting hole, and the locking connection is used to lock onto the side wall of the battery cell. Claim 12 A battery pack according to any one of claims 1 to 9, wherein the battery pack further comprises a bottom protection plate, the bottom protection plate is installed on one side facing away from the battery cell, and a pressure relief chamber is formed between the bottom protection plate and the support assembly. Claim 13 In claim 12, the battery pack further comprises a plurality of support members, and the plurality of support members are spaced apart and installed between the support assembly and the bottom protection plate. Claim 14 In paragraph 13, the support member is a buffer block, and the buffer block is bonded to the support assembly and the bottom protection plate, respectively, in a battery pack. Claim 15 In claim 12, the battery pack further comprises a third insulating member, and the battery pack is installed on one side where the bottom protective plate approaches the support assembly and is located within the pressure relief chamber. Claim 16 A battery pack according to claim 15, wherein the projected area of ​​the bottom protection plate of the third insulating member is 110% or more of the projected area of ​​the bottom protection plates of a plurality of battery cells.

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