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 the priority of a Chinese patent application with an application number of 202420636011.8, which was filed with the Chinese Patent Office on March 28, 2024. All the contents of the above application are incorporated herein by reference.

[0002] This application relates to the technical field of batteries, for example, battery cases and battery packs.

Background Art

[0003] With the rapid development of the new energy vehicle industry, lithium battery modules are widely applied to new energy vehicles. A lithium battery module includes a battery case body and a battery cell module provided in the battery case body. In order to prevent the thermal runaway of an individual single cell in the lithium battery module from affecting the safety of other surrounding single cells, a corresponding thermal runaway design is usually arranged. In the related art, regarding the thermal runaway of a lithium battery module, it is designed to prevent the thermal runaway gas of a single single cell from affecting the thermal runaway of other single cells by providing a pressure relief passage in the battery case body to quickly discharge the thermal runaway gas of a single single cell.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The pressure relief passage is usually formed by spacing between the tray on which the battery cell module is placed and the bottom protection plate of the battery case body. The bottom protection plate is only connected to the frame of the case body at the edge, and the middle position floats in the air, resulting in poor connection strength and impact resistance.

Means for Solving the Problems

[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 a housing chamber, an opening communicating with the housing chamber is provided on one side along a first direction, the bottom protective plate is detachably connected to the opening, the bracket is attached to the chamber wall of the housing chamber and forms a pressure relief passage configured to release pressure from runaway thermal gas of the battery cell assembly in the bracket, spaced apart from the bottom protective plate, and the suction cup is provided on the side facing the bottom protective plate and in contact with the bottom protective plate.

[0006] In a second aspect, an embodiment of the present application provides a battery pack comprising 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 the side of the bracket furthest from the bottom protective plate. [Effects of the Invention]

[0007] In some embodiments of the present invention, by making the bottom protective plate and the case body detachably connected, the production convenience of the battery case can be effectively improved, the replacement of subsequent bottom protective plates can be facilitated, and the maintenance costs of the battery case can be reduced. The connection between the bracket and the bottom protective plate by suction cups is convenient to attach and detach, effectively improves the connection strength of the middle region of the bottom protective plate, and by supporting the bottom protective plate with suction cups, the impact resistance of the bottom protective plate can be further improved, and deformation of the bottom protective plate due to external impacts can be reduced. Furthermore, when thermal runaway gas from the battery cell assembly enters the pressure relief passage, the increase in air pressure in the pressure relief passage causes the suction cups to detach from the connection with the bottom protective plate, and the bottom protective plate is pushed outward in the direction away from the bracket by the air pressure of the thermal runaway gas, thereby increasing the volume of the pressure relief passage and improving the safety of use of the battery case. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the structure of a battery case relating to several implementation methods of the present invention. [Figure 2] This is a cross-sectional view of a battery case relating to several implementation methods of the present invention. [Figure 3] This is a schematic diagram of the local structure of a battery case relating to several implementation methods of the present invention. [Modes for carrying out the invention]

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

[0010] In the description of this application, unless otherwise explicitly provided and limited, the terms “connected,” “connection,” and “fixed” should be understood in a broad sense. For example, they may be fixed connections, detachable connections, or integrated, mechanical connections, electrical connections, direct connections, indirect connections via an intermediate mediator, or internal communication between two elements or an interaction between two elements. A person skilled in the art will understand the specific meaning of these terms in this application depending on the specific circumstances.

[0011] In this application, unless otherwise explicitly provided and limited, the presence of a first feature "above" or "below" a second feature may include direct contact between the first and second features, or it may include contact between the first and second features via other features between them, without direct contact. Furthermore, the presence of a first feature "above," "above," and "on the top surface" of a second feature may include the first feature being directly above and diagonally above the second feature, or indicating that the horizontal height of the first feature is greater than that of the second feature. The presence of a first feature "below," "below," and "on the bottom surface" of a second feature may include the first feature being directly below and diagonally below the second feature, or indicating that the horizontal height of the first feature is lower than that of the second feature.

[0012] The embodiment of the present invention provides a battery case and battery pack that have a simple structure and high connection strength and impact resistance of the bottom protective plate.

[0013] As shown in Figures 1 and 2, the battery case of the embodiment of the present invention comprises a case body 1, a bottom protective plate 2, a bracket 3, and a suction cup 4. The case body 1 has a housing chamber 11, and an opening communicating with the housing chamber 11 is provided on one side along the first direction, and the bottom protective plate 2 is detachably connected to the opening. The bracket 3 is attached to the chamber wall of the housing chamber 11 and forms a pressure relief passage 12 at a distance from the bottom protective plate 2, and the pressure relief passage 12 is configured to release pressure from the thermal runaway gas of 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, with the first direction being the height direction. The bottom protective plate 2 and the case body 1 are detachably connected. By disassembling one complex integrated component into multiple simple parts during production, the convenience of producing the battery case is effectively improved, and replacement of the bottom protective plate 2 if it is subsequently damaged by impact is made easy, reducing the maintenance cost of the battery case. The connection between the bracket 3 and the bottom protective plate 2 by suction cups 4 is convenient to attach and detach, simpler to connect than detachable connection methods such as bolt connections, requires less working force, and provides good sealing performance at the connection point, ensuring the closure performance of the pressure relief passage 12, preventing moisture or other impurities from entering the battery case and damaging the battery cell assembly. While reducing situations that affect normal use, the connection strength of the middle region of the bottom protective plate 2 can be effectively improved, and by supporting the bottom protective plate 2 with the suction cup 4, the impact resistance of the bottom protective plate 2 can be further improved. That is, when the bottom protective plate 2 is subjected to an external impact, some of the impact force is mitigated by the support force provided by the suction cup 4, and deformation due to the external impact can be reduced. Furthermore, when thermal runaway gas from the battery cell assembly enters the pressure relief passage 12, the increase in air pressure in the pressure relief passage 12 causes the suction cup 4 to detach from the connection with the bottom protective plate 2, and the bottom protective plate 2 is pushed outward in the direction away from the bracket 3 by the air pressure of the thermal runaway gas, thereby increasing the volume of the pressure relief passage 12 and improving the safety of use of the battery case.

[0015] For example, the bottom of the case body 1 is provided with a first screw hole, and the bottom protective plate 2 is provided with a plurality of first through holes. The bottom protective plate 2 and the case body 1 are connected by passing a first bolt through the first through hole and rotating it inside the first screw hole. This method allows for easy attachment and detachment of the screw connection and provides a strong connection. In other embodiments, the bottom protective plate 2 may be provided with a locking button, and the case body 1 may be provided with a locking groove, and the connection may be made by engaging the locking button and the locking groove.

[0016] In some embodiments, as shown in Figures 2 and 3, the bracket 3 is provided with multiple communication holes 31 running through it, the number of communication holes 31 corresponding one-to-one with the number of battery cells in the battery cell assembly, and the holes are positioned directly opposite the explosion-proof valves of the battery cells. The installation of the communication holes 31 allows gas generated when a battery cell experiences thermal runaway to be quickly transmitted into the pressure relief passage 12, and since each battery cell's pressure relief valve is provided with one communication hole 31, the pressure relief distance is shortened, reducing the impact of thermal runaway gases spreading at high temperatures on other battery cells.

[0017] In some embodiments, as shown in Figures 2 and 3, a plurality of insertion grooves 32 are recessed on the side of the bracket 3 furthest from the bottom protective plate 2, and a communication hole 31 is provided that penetrates the bottom of the insertion groove 32, and the insertion groove 32 is configured for inserting battery cells. The installation of the insertion grooves 32 facilitates the positioning of the battery cell when attaching it to the bracket 3, improves the positioning accuracy of the battery cell attachment, and strengthens the connection strength of the battery cell attachment by limiting the circumferential side of the battery cell with the groove walls of the insertion groove 32.

[0018] In some embodiments, as shown in Figure 2, a plurality of support portions 33 are provided at intervals and protruding from the side of the bracket 3 facing the bottom protective plate 2, and at least one suction cup 4 is provided on each support portion 33. The installation of the support portions 33 ensures the connection between the suction cup 4 and the bottom protective plate 2 when there is a certain distance between the bottom protective plate 2 and the bracket 3, and reinforces the support of the suction cup 4 by the bracket 3.

[0019] In some embodiments, as shown in Figure 1, an exhaust port 13 communicating with a pressure relief passage 12 is provided in the case body 1. By providing the exhaust port 13, runaway thermal gases generated in the battery cells can be quickly discharged to the outside of the case body 1, preventing the runaway thermal gases from accumulating 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, avoids the exhaust port 13 facing the ground during normal use, and reduces the occurrence of situations where impurities or moisture enter 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. The explosion-proof piece can be punctured when the thermal runaway gas reaches a certain pressure, opening the exhaust port 13 and allowing the pressure relief passage 12 to communicate with the outside. The installation of the explosion-proof piece blocks the exhaust port 13 during normal use, ensuring the airtightness of the pressure relief passage 12, 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 battery case body 1.

[0021] In some embodiments, the explosion-proof piece has a thickness at its central position that is smaller than the thickness at its edge position. This design ensures the strength of the connection between the explosion-proof piece and the case body 1, and further ensures that the explosion-proof piece is detonated preferentially from the weaker areas by the impact of runaway thermal gas, thereby guaranteeing the safety of use of the explosion-proof piece.

[0022] In some embodiments, the bracket 3 is removably connected to the chamber wall of the accommodation chamber 11. By making it removable, it facilitates the production of the battery case, reduces the production cost, enables the individual replacement of the bracket 3 and the case body 1 in the case of later maintenance, and results in low maintenance costs. In this embodiment, a second through hole is provided in the bracket 3, and a second screw hole is provided in the case body 1. By passing a second bolt through the second through hole and turning it into the second screw hole, the bracket 3 and the case body 1 are fixedly connected, the connection is strong, and the connection stability of the bracket 3 is guaranteed. In other embodiments, the bracket 3 may be connected by other removable methods such as latching.

[0023] In some embodiments, a guide groove 14 extending along the first direction in length is recessed and provided on the chamber wall of the accommodation chamber 11, and a guide portion inserted into the guide groove 14 is provided on the bracket 3. Through the cooperation between the guide portion and the guide groove 14, the guidance during the installation of the bracket 3 can be strengthened, and the installation accuracy of the connection of the bracket 3 can be improved.

[0024] As shown in FIGS. 1 to 3, the 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. The battery cell assembly is attached to the bracket 3 of the battery case and is located on the side far from the bottom protection plate 2 of the bracket 3. In the battery case of the battery pack, a pressure relief passage 12 is formed with a gap between the bracket 3 and the bottom protection plate 2. Thereby, the battery cell gradually releases the thermal runaway gas, and the use safety of the battery pack is enhanced.

[0025] In some embodiments, the battery pack further includes a pressing plate 5. On the side of the bottom protection plate 2 of the case body 1 of the battery case that is far from the bottom protection plate 2, mounting ports communicating with each other are provided in the accommodation chamber 11 of the case body 1. A pressing plate 5 is provided at the mounting port, and the pressing plate 5 is configured to firmly abut against the battery cell assembly. Regarding the mounting order of the battery cell module, first, the bottom protection plate 2 is mounted on the case body 1 to close the opening of the case body 1, and then the bracket 3 provided with the battery cell assembly is mounted in the accommodation chamber 11. When mounting, the bracket 3 is mounted, and only by adsorbing the suction cup 4 to the bottom protection plate 2, the reinforcing connection at the middle position of the bottom protection plate 2 can be completed. Finally, it can be understood that the pressing plate 5 is mounted in the case body 1 so as to firmly abut against the battery cell assembly to ensure the mounting stability of the battery cell assembly.

[0026] In some embodiments, at the position corresponding to the protruding pole columns of each battery cell of the battery cell assembly on the pressing plate 5, a retreat hole is recessed. By installing the retreat hole, the occupied space of the protruding pole columns of the battery cells is reduced, the utilization of the space in the accommodation chamber 11 is improved, and the mounting stability of the battery cells can be reinforced by restricting the pole columns by the hole wall of the retreat hole.

[0027] In some embodiments, in the process of assembling the battery pack, potting adhesive can be injected into the pressing plate 5 and the bracket 3 so as to reinforce the mounting stability of the battery cell assembly and the heat insulation between the battery cells.

[0028] In some embodiments, a cooling gel mat may be further provided on the side of the bottom protection plate 2 facing the bracket 3. The cooling gel mat has good thermal conductivity and can accelerate the heat dissipation of the battery cell assembly or the temperature reduction of the thermal runaway gas.

[0029] In the explanations in this paper, terms such as "up" and "down" refer to directions or positional relationships based on the directions or positional relationships shown in the drawings. They are merely used to facilitate explanation and simplify operation, and should be understood as not indicating or implying that the device or element in question has a specific direction or must be configured and operated in a specific direction.

[0030] In this specification, the term "Example" means that the specific features, structure, materials, or properties related to that example are included in at least one example or instance of the Application. In this specification, a schematic representation of a term does not necessarily refer to the same example.

[0031] Furthermore, although this specification has been described according to embodiments, each embodiment does not contain only one independent technical idea, and this method of description in the specification is for clarity only. Those skilled in the art should treat the specification as a whole and understand that the technical ideas in each embodiment may be combined as appropriate to form other embodiments understandable to those skilled in the art. [Explanation of Symbols]

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

Claims

1. The case consists of the main body, a bottom protective plate, a bracket, and a suction cup. The case body has a storage chamber, an opening communicating with the storage chamber is provided on one side along the first direction, the bottom protective plate is detachably connected to the opening, the bracket is attached to the chamber wall of the storage chamber and forms a pressure relief passage at a distance from the bottom protective plate, configured to release pressure from thermal runaway gas of the battery cell assembly in the bracket, the suction cup that abuts against the bottom protective plate is provided on the side facing the bottom protective plate, and a plurality of support parts, each provided with at least one of the suction cups, are provided at intervals and protruding from the side of the bracket facing the bottom protective plate. Battery case.

2. The bracket is provided with multiple communication holes through which the number of holes corresponds one-to-one with the number of battery cells in the battery cell assembly and which are positioned directly opposite the explosion-proof valves of the battery cells. The battery case according to claim 1.

3. On the side of the bracket furthest from the bottom protective plate, a plurality of insertion grooves are recessed in the bottom of the groove, through which the communication holes are provided, and which are configured for inserting the battery cells. The battery case according to claim 2.

4. The case body is provided with an exhaust port that communicates with the pressure relief passage. A battery case according to any one of claims 1 to 3.

5. The system further comprises explosion-proof pieces configured to close the exhaust port. The battery case according to claim 4.

6. The bracket is removably connected to the wall of the containment chamber. A battery case according to any one of claims 1 to 3.

7. A guide groove is recessed in the wall of the aforementioned storage chamber, with a length extending along the first direction, and a guide portion is provided on the bracket that is inserted into the guide groove. The battery case according to claim 6.

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

9. The battery case further comprises a retaining plate provided on the side of the case body of the battery case that is farther from the bottom protective plate, and provided in a mounting opening that communicates with the housing chamber of the case body, and configured to firmly contact the battery cell assembly. The battery pack according to claim 8.

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