Battery case and battery pack

Abstract

To provide a battery case having a pressure relief passage provided between a bracket and a bottom protective plate, which improves the impact resistance of the bottom protective plate and the connection strength with the bracket.SOLUTION: A battery case includes a case body 1, a bottom protective plate 2, a bracket 3, and a suction cup 4. The case body 1 includes an accommodation chamber 11, has an opening communicating with the accommodation chamber 11 provided on one side along the first direction, with the bottom protective plate 2 removably connected to the opening. The bracket 3 is attached to the chamber wall of the accommodation chamber 11 and is spaced apart from the bottom protective plate 2 to form a pressure relief passage 12 configured to relieve pressure against thermal runaway gas in the battery cell assembly in the bracket 3. The suction cup 4 is provided on the side of the bracket 3 facing the bottom protective plate 2, and the suction cup 4 abuts against the bottom protective plate 2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This application claims priority from a Chinese patent application bearing application number 202420636011.8, filed with the China Patent Office on March 28, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of batteries, for example, battery cases and battery packs. [Background technology]

[0003]

[0003] With the rapid development of the new energy vehicle industry, lithium battery modules have been widely applied in new energy vehicles. A lithium battery module includes a battery case body and a battery cell module installed in the battery case body, and is usually equipped with a corresponding thermal runaway design to prevent thermal runaway of an individual cell in the lithium battery module from affecting the safety of other surrounding cells. In the related art, the thermal runaway of a lithium battery module is designed by providing a pressure relief passage in the battery case body to quickly discharge thermal runaway gas from a single cell, thereby preventing it from affecting the thermal runaway of other cells. Summary of the Invention [Problem to be solved by the invention]

[0004] The pressure relief passage is usually formed by a gap between the tray on which the battery cell module is placed and the bottom protective plate of the battery case body, and the bottom protective plate is connected to the frame of the case body only at its edges, with the middle part floating in the air, resulting in poor connection strength and impact resistance. [Means for solving the problem]

[0005] In a first aspect, an embodiment of the present application provides a battery case comprising a case body, a bottom protective plate, a bracket, and a suction cup, wherein the case body has an accommodating chamber and an opening communicating with the accommodating chamber on one side along a first direction, the bottom protective plate being removably connected to the opening, the bracket being attached to a chamber wall of the accommodating chamber and spaced apart from the bottom protective plate to form a pressure relief passage configured to relieve pressure against thermal runaway gas in a battery cell assembly in the bracket, and the suction cup being abutted against the bottom protective plate on the side facing the bottom protective plate.

[0006] In a second aspect, an embodiment of the present application provides a battery pack including a battery cell assembly and a battery case as described in the first aspect, wherein the battery cell assembly is attached to a bracket of the battery case and is located on a side of the bracket farther from the bottom protective plate. [Effects of the Invention]

[0007] In some embodiments of the present application, the bottom protective plate and the case body are detachably connected, which effectively improves the production convenience of the battery case and makes it easier to replace the bottom protective plate later, thereby reducing the maintenance costs of the battery case. The connection between the bracket and the bottom protective plate using suction cups is convenient for attachment and detachment and effectively improves the connection strength of the middle region of the bottom protective plate. Supporting the bottom protective plate with suction cups further improves the impact resistance of the bottom protective plate and reduces deformation of the bottom protective plate due to external impact. Furthermore, when thermal runaway gas from the battery cell assembly enters the pressure relief passage, the increase in air pressure within the pressure relief passage allows the suction cup to separate from the bottom protective plate, and the bottom protective plate is pushed by the air pressure of the thermal runaway gas and protrudes outward away from the bracket, thereby increasing the volume of the pressure relief passage and improving the safety of the battery case. [Brief explanation of the drawings]

[0008] [Figure 1] 1A to 1C are structural schematic diagrams of battery cases according to some implementation methods of the present application. [Figure 2] 1 is a cross-sectional view of a battery case according to some implementations of the present application. [Figure 3] 1A to 1C are schematic diagrams illustrating the local structure of a battery case according to some implementations of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present application will be described in conjunction with the drawings, and the described embodiments are some of the embodiments related to the present application.

[0010] In the description of this application, unless otherwise clearly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or integration, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, internal communication between two elements, or an interaction between two elements. Those skilled in the art can understand the specific meaning of the terms used in this application depending on the specific situation.

[0011] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, a first feature being "above," "above," and "on the upper surface" of a second feature may include the first feature being directly above and diagonally above the second feature, or the first feature having a higher horizontal height than the second feature. A first feature being "below," "below," and "on the lower surface" of a second feature may include the first feature being directly below and diagonally below the second feature, or the first feature having a lower horizontal height than the second feature.

[0012] The embodiments of the present application provide a battery case and a battery pack that have a simple structure, high connection strength of the bottom protection plate, and high impact resistance.

[0013] As shown in Figures 1 and 2, the battery case of the present application comprises a case body 1, a bottom protective plate 2, a bracket 3, and a suction cup 4. The case body 1 has an accommodating chamber 11 and has an opening on one side along the first direction that communicates with the accommodating chamber 11. The bottom protective plate 2 is removably connected to the opening. The bracket 3 is attached to the chamber wall of the accommodating chamber 11 and is spaced apart from the bottom protective plate 2 to form a pressure relief passage 12. The pressure relief passage 12 is configured to release pressure against thermal runaway gas in the battery cell assembly in the bracket 3. A suction cup 4 is provided on the side of the bracket 3 facing the bottom protective plate 2, and the suction cup 4 abuts against the bottom protective plate 2.

[0014] When the battery case is in normal use, the bottom protective plate 2 is located at the bottom, and the first direction is the height direction. The bottom protective plate 2 and the case body 1 are removably connected, i.e., one complex integrated member is disassembled into several simple parts for production, which effectively improves the convenience of battery case production and makes it easy to replace the bottom protective plate 2 if it is damaged by impact later, thereby reducing the maintenance cost of the battery case. The connection between the bracket 3 and the bottom protective plate 2 by the suction cup 4 is convenient for attachment and detachment, is simpler than removable connection methods such as bolt connection, requires less work, and has good sealing performance at the connection position, guaranteeing the closure performance of the pressure relief passage 12, and preventing moisture or other impurities from entering the battery case and causing the battery cell assembly to malfunction. While reducing the impact on normal use, the connection strength of the central region of the bottom protective plate 2 is effectively improved, and by supporting the bottom protective plate 2 with the suction cups 4, the impact resistance of the bottom protective plate 2 is further improved. That is, when the bottom protective plate 2 is subjected to an external impact, the supporting force provided by the suction cups 4 can partially absorb the impact force and reduce deformation caused by the external impact. Furthermore, when thermal runaway gas from the battery cell assembly enters the pressure relief passage 12, the increase in air pressure within the pressure relief passage 12 causes the suction cups 4 to separate from the bottom protective plate 2, and the bottom protective plate 2 is pushed outward by the air pressure of the thermal runaway gas, away from the bracket 3, thereby increasing the volume of the pressure relief passage 12 and improving the safety of the battery case.

[0015] For example, a first screw hole is provided at the bottom of the case body 1, and a plurality of first through holes are provided in the bottom protective plate 2, and first bolts are passed through the first through holes and turned into the first screw holes to connect the bottom protective plate 2 and the case body 1, which makes the screw connection easy to attach and detach and provides a strong connection. In another embodiment, a locking button may be provided on the bottom protective plate 2, and a locking groove may be provided on the case body 1, and the connection may be made by engaging the locking button with the locking groove.

[0016] 2 and 3, the bracket 3 is provided with a plurality of communication holes 31 extending therethrough. The number of communication holes 31 corresponds one-to-one with the number of battery cells in the battery cell assembly, and the communication holes 31 are located directly opposite the explosion-proof valves of the battery cells. The provision of the communication holes 31 allows gas generated in the event of thermal runaway to be quickly transferred into the pressure relief passage 12. Each battery cell has a corresponding communication hole 31, which shortens the pressure relief distance and reduces the impact of thermal runaway gas spreading at high temperatures on other battery cells.

[0017] 2 and 3, in some embodiments, a plurality of insertion grooves 32 are recessed on the side of the bracket 3 away from the bottom protective plate 2, and communication holes 31 are provided through the bottoms of the insertion grooves 32, which are configured for inserting battery cells. The provision of the insertion grooves 32 makes it easier to position the battery cells when attaching them to the bracket 3, improving the positioning accuracy of the battery cell attachment, and the groove walls of the insertion grooves 32 define the periphery of the battery cells, thereby increasing the connection strength of the attached battery cells.

[0018] 2, a plurality of support portions 33 are provided at intervals on the side of the bracket 3 facing the bottom protection plate 2, and each support portion 33 is provided with at least one suction cup 4. The provision of the support portions 33 ensures the connection between the suction cups 4 and the bottom protection plate 2 when there is a certain distance between the bottom protection plate 2 and the bracket 3, and reinforces the support of the suction cups 4 by the bracket 3.

[0019] 1 , the case body 1 is provided with an exhaust port 13 that communicates with the pressure relief passage 12. The provision of the exhaust port 13 allows thermal runaway gas generated in the battery cells to be quickly discharged to the outside of the case body 1, preventing the thermal runaway gas from gathering in the pressure relief passage 12 and causing an explosion. In this embodiment, the exhaust port 13 is provided on the side wall of the case body 1, which, compared to providing the exhaust port 13 on the bottom protective plate 2, prevents the exhaust port 13 from facing the ground during normal use and reduces the occurrence of impurities or moisture entering the pressure relief passage 12.

[0020] In some embodiments, the battery case further includes an explosion-proof piece configured to block the exhaust port 13. When the thermal runaway gas reaches a certain pressure, the explosion-proof piece is broken to open the exhaust port 13 and allow the pressure relief passage 12 to communicate with the outside. The installation of the explosion-proof piece closes the exhaust port 13 during normal use, ensuring the sealing of the pressure relief passage 12 and preventing external impurities from entering the pressure relief passage 12 and affecting the use of the battery cells, thereby improving the safety of use of the case body 1 of the battery case.

[0021] In some embodiments, the thickness of the explosion-proof piece at the center is smaller than the thickness at the edge, and this design can ensure the strength of the connection between the explosion-proof piece and the case body 1, and also ensure that the explosion-proof piece is blown up first in the weak areas by the impact of thermal runaway gas, thereby ensuring the safety of using the explosion-proof piece.

[0022] In some embodiments, the bracket 3 is removably connected to the chamber wall of the receiving chamber 11. This detachability facilitates production of the battery case, reducing production costs, and allows the bracket 3 and the case body 1 to be replaced separately for later maintenance, reducing maintenance costs. In this embodiment, the bracket 3 has a second through-hole and the case body 1 has a second screw hole. A second bolt is passed through the second through-hole and threaded into the second screw hole to securely connect the bracket 3 to the case body 1, providing a strong connection and ensuring stable connection of the bracket 3. In other embodiments, the bracket 3 may be connected in other detachable ways, such as by fastening.

[0023] In some embodiments, a guide groove 14 extending along the first direction is recessed into the chamber wall of the accommodation chamber 11, and the bracket 3 is provided with a guide portion that is inserted into the guide groove 14. The cooperation between the guide portion and the guide groove 14 reinforces the guide when the bracket 3 is attached, and improves the attachment accuracy of the connection of the bracket 3.

[0024] As shown in Figures 1 to 3, an embodiment of the present application further provides a battery pack including a battery cell assembly and the battery case of any of the above embodiments, where the battery cell assembly is attached to a bracket 3 of the battery case and is located on the side of the bracket 3 farther from the bottom protective plate 2. In the battery case of the battery pack, the bracket 3 and the bottom protective plate 2 are spaced apart to form a pressure relief passage 12, which allows the battery cells to gradually release thermal runaway gas and improves the safety of the battery pack.

[0025] In some embodiments, the battery pack further includes a retaining plate 5, and the side of the case body 1 of the battery case away from the bottom protective plate 2 is provided with an attachment opening that communicates with the accommodation chamber 11 of the case body 1, and the retaining plate 5 is provided at the attachment opening, and the retaining plate 5 is configured to firmly abut against the battery cell assembly. It can be understood that the battery cell module is installed in the following order: first, the bottom protective plate 2 is attached to the case body 1 to close the opening of the case body 1, and then the bracket 3 on which the battery cell assembly is installed is installed inside the accommodation chamber 11; during installation, simply attaching the bracket 3 and adhering the suction cup 4 to the bottom protective plate 2 completes the reinforcing connection at the center position of the bottom protective plate 2; and finally, the retaining plate 5 is installed inside the case body 1 so that it firmly abuts against the battery cell assembly, ensuring the stability of the installation of the battery cell assembly.

[0026] In some embodiments, recessed recesses are provided in the retaining plate 5 at positions corresponding to the protruding poles of each battery cell in the battery cell assembly. The provision of the recesses reduces the space occupied by the protruding poles of the battery cells, improving the utilization of space within the accommodation chamber 11, and the walls of the recesses restrict the poles, thereby reinforcing the stability of the battery cell installation.

[0027] In some embodiments, a potting adhesive can be injected into the retaining plate 5 and the bracket 3 during the assembly process of the battery pack to enhance the mounting stability of the battery cell assembly and the thermal insulation between the battery cells.

[0028] In some embodiments, a cooling gel mat may be further provided on the side of the bottom protective plate 2 facing the bracket 3, which has good thermal conductivity and can speed up the heat dissipation of the battery cell assembly or the cooling of thermal runaway gases.

[0029] In the description herein, it should be understood that the terms "upper," "lower," and other orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, are for ease of description and simplification of operation only, and do not indicate or imply that such devices or elements must have a particular orientation or be configured and operated in a particular orientation.

[0030] In the description of this specification, the description of a reference to the term "embodiment" means that the specific feature, structure, material, or characteristic associated with the embodiment is included in at least one embodiment or example of the present application. In this specification, schematic representations of terms do not necessarily refer to the same embodiment.

[0031] Furthermore, although this specification has been described according to embodiments, each embodiment does not include only one independent technical solution, and such description of the specification is for the sake of clarity, and those skilled in the art should treat the specification as a whole, and should understand that the technical solutions in each example may be combined as appropriate to form other embodiments that are understandable to those skilled in the art. [Explanation of symbols]

[0032] 1...Case body, 11...Accommodation chamber, 12...Pressure relief passage, 13...Exhaust port, 14...Guide groove, 2...Bottom protective plate, 3...Bracket, 31...Communication hole, 32...Installation groove, 33...Support part, 4...Suction cup, 5...Pressure plate.

Claims

1. The device comprises a case body, a bottom protection plate, a bracket, and a suction cup, the case body has an accommodation chamber, and an opening communicating with the accommodation chamber is provided on one side along a first direction, the bottom protective plate is removably connected to the opening, the bracket is attached to a chamber wall of the accommodation chamber and is spaced apart from the bottom protective plate to form a pressure relief passage configured to relieve pressure against thermal runaway gas in the battery cell assembly at the bracket, and the suction cup is provided on the side facing the bottom protective plate to abut against the bottom protective plate; Battery case.

2. the bracket is provided with a plurality of communication holes extending therethrough, the number of which corresponds one-to-one to the number of battery cells in the battery cell assembly and which are provided directly opposite the explosion-proof valves of the battery cells; The battery case according to claim 1 .

3. The bracket has a bottom on the side farther from the bottom protective plate, through which the communication holes pass, and a plurality of recessed insertion grooves configured for inserting the battery cells. The battery case according to claim 2 .

4. A plurality of support portions are provided at intervals on the side of the bracket facing the bottom protective plate, and protrude from the bracket, each of which is provided with at least one suction cup. The battery case according to any one of claims 1 to 3.

5. An exhaust port communicating with the pressure relief passage is opened in the case body. The battery case according to any one of claims 1 to 3.

6. Further comprising an explosion-proof piece configured to block the exhaust port. The battery case according to claim 5 .

7. The bracket is removably connected to a chamber wall of the chamber. The battery case according to any one of claims 1 to 3.

8. a guide groove extending along the first direction is recessed in a chamber wall of the accommodation chamber, and a guide portion inserted into the guide groove is provided on the bracket; The battery case according to claim 7.

9. a battery cell assembly and a battery case according to any one of claims 1 to 3, wherein the battery cell assembly is attached to a bracket of the battery case and is located on a side of the bracket farther from the bottom protective plate; Battery pack.

10. a retainer plate provided in an attachment opening that is provided on the side of the case body of the battery case away from the bottom protective plate and communicates with the storage chamber of the case body, the retainer plate being configured to firmly abut against the battery cell assembly; The battery pack according to claim 9.

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