Heat insulation panels, battery modules, and battery packs

Abstract

This application relates to a heat insulation board, a battery module, and a battery pack. The heat insulation board includes a heat insulation frame, a composite thermally conductive material layer, and a heat-shrinkable film. The heat insulation frame is a support frame with an opening. The heat-shrinkable film is connected to the opening of the heat insulation frame to surround the heat insulation frame and form a receiving cavity. The composite thermally conductive material layer fills the receiving cavity. When within the normal temperature range, the composite thermally conductive material layer can provide good thermal conductivity. The composite thermally conductive material layer and the heat insulation frame form at least one contact interface. When the ambient temperature reaches a preset temperature, the heat-shrinkable film deforms and detaches from the opening of the heat insulation frame. The composite thermally conductive material layer changes phase to liquid and flows out from the opening of the heat insulation frame. At this time, only the heat insulation frame remains of the heat insulation board, and the average thermal conductivity of the heat insulation board decreases, thereby suppressing heat spread.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a heat insulation plate, a battery module, and a battery pack. Background Technology

[0002] With the rapid development of electric vehicles, the safety issues of electric vehicle power battery systems have constrained this rapid development. Safety incidents involving electric vehicle power batteries are primarily characterized by the propagation of thermal runaway from battery modules. After a single battery cell experiences thermal runaway, the high temperature rapidly transfers to adjacent cells, causing a chain reaction of thermal runaway and resulting in fires, explosions, and other safety accidents. Suppressing the spread of thermal runaway heat from the power battery to surrounding cells is a crucial means of ensuring the safety of passengers' lives and property.

[0003] Currently, the main method to suppress heat spread in power batteries is to add thermally insulating materials with high thermal resistance between the batteries to isolate the heat generated by each battery. However, this method is not conducive to heat dissipation during normal battery use, and poor heat dissipation can even lead to abnormal temperature rise in the battery. Summary of the Invention

[0004] Therefore, it is necessary to provide a heat insulation plate, battery module, and battery pack to address the problem that traditional heat insulation materials are not conducive to heat dissipation during normal battery use.

[0005] An insulation panel, comprising:

[0006] Insulation frame, forming a support frame with openings;

[0007] A heat-shrinkable film is connected to the opening of the heat insulation frame to surround the heat insulation frame and form a receiving cavity; and

[0008] A composite thermally conductive material layer is filled in the cavity, and the composite thermally conductive material layer forms at least one contact interface with the thermal insulation frame;

[0009] When the ambient temperature reaches the preset temperature, the heat-shrinkable film deforms and falls off from the opening of the heat insulation frame. The composite thermally conductive material layer changes phase to liquid and flows out from the opening of the heat insulation frame.

[0010] In one embodiment, the thermal insulation frame includes:

[0011] The first crossbeam, the end of which is connected to the heat-shrinkable film;

[0012] A connecting beam, one end of which is connected to the middle connecting portion of the first crossbeam; and

[0013] The second crossbeam has a middle connecting portion connected to the other end of the connecting beam, and the end of the second crossbeam is connected to the heat-shrinkable film.

[0014] In one embodiment, the first crossbeam is provided with an air hole that communicates with the receiving cavity.

[0015] In one embodiment, the contact interface is curved and extends along the direction from the connecting beam toward the opening of the thermal insulation frame, facilitating the flow of the composite thermally conductive material layer.

[0016] In one embodiment, the composite thermally conductive material layer is composed of a mixture of high thermal conductivity powder and a phase change material.

[0017] In one embodiment, the high thermal conductivity powder is any one or more of copper powder, aluminum powder, or graphite powder, and the phase change material is any one or more of paraffin wax, inorganic hydrated salt, or phase change silicone grease.

[0018] In one embodiment, the thermal insulation frame is any one or more of aluminum silicate fiberboard, glass fiberboard, mica board, or microporous calcium silicate board.

[0019] In one embodiment, the heat-shrinkable film is any one or more of plastic polyethylene composite film, polyolefin heat-shrinkable composite film, or low-pressure polyethylene composite film.

[0020] In one embodiment, the phase transition temperature of the composite thermally conductive material layer is 45°C to 60°C, and the deformation temperature of the heat-shrinkable film is greater than 80°C.

[0021] A battery module, comprising:

[0022] Multiple battery cells;

[0023] The heat insulation plate described in any of the above embodiments is disposed between two adjacent battery cells.

[0024] A battery pack, comprising:

[0025] The battery modules described in several of the above embodiments.

[0026] The aforementioned heat insulation board includes a heat insulation frame, a composite thermally conductive material layer, and a heat-shrinkable film. The heat insulation frame is a support frame with an opening. The heat-shrinkable film is connected to the opening of the heat insulation frame to surround the heat insulation frame and form a receiving cavity. The composite thermally conductive material layer fills the receiving cavity. Within the normal temperature range, the composite thermally conductive material layer provides good thermal conductivity. The composite thermally conductive material layer forms at least one contact interface with the heat insulation frame. When the ambient temperature reaches a preset temperature, the heat-shrinkable film deforms and detaches from the opening of the heat insulation frame. The composite thermally conductive material layer changes phase to liquid and flows out from the opening of the heat insulation frame. At this point, only the heat insulation frame remains of the heat insulation board, and the average thermal conductivity of the heat insulation board decreases, thereby inhibiting heat spread. Attached Figure Description

[0027] Figure 1 This is a structural diagram of a heat insulation panel provided in one embodiment of this application;

[0028] Figure 2 This is a structural diagram of a heat insulation panel provided in one embodiment of this application;

[0029] Figure 3 This is a structural diagram of a thermal insulation frame provided in one embodiment of this application;

[0030] Figure 4 This is a structural diagram of a thermal insulation frame provided in one embodiment of this application;

[0031] Figure 5 This is a structural diagram of a battery module provided in one embodiment of this application;

[0032] Figure 6 This is a simulation result diagram of thermal equilibrium provided in one embodiment of this application;

[0033] Figure 7 A thermal equilibrium simulation result diagram for a lithium-ion battery with a thermal insulation mica plate of the same thickness added between them, according to an embodiment of this application;

[0034] Figure 8 A simulation result diagram of heat spread when the heat shrink film does not fall off, provided in one embodiment of this application;

[0035] Figure 9 This is a simulation result diagram of the thermal spread during normal shedding of heat shrink film according to an embodiment of this application.

[0036] Explanation of reference numerals for main components

[0037] Insulation board 10

[0038] Thermal insulation frame 100

[0039] Reception cavity 101

[0040] First crossbeam 110

[0041] Air hole 111

[0042] Connecting beam 120

[0043] Second crossbeam 130

[0044] Composite thermally conductive material layer 200

[0045] 300 heat shrink film

[0046] Battery Module 20

[0047] 400 cells Detailed Implementation

[0048] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0049] It should be noted that when a component is said to be "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] Please see Figure 1 One embodiment of this application provides a heat insulation board 10. The heat insulation board 10 includes a heat insulation frame 100, a composite thermally conductive material layer 200, and a heat shrink film 300.

[0052] The thermal insulation frame 100 forms a support frame with an opening. The heat-shrinkable film 300 is connected to the opening of the thermal insulation frame 100 to surround the thermal insulation frame 100 and form a receiving cavity 101. The composite thermally conductive material layer 200 fills the receiving cavity 101. The composite thermally conductive material layer 200 forms at least one contact interface with the thermal insulation frame 100. When the ambient temperature reaches a preset temperature, the heat-shrinkable film 300 deforms and detaches from the opening of the thermal insulation frame 100, the composite thermally conductive material layer 200 changes phase to liquid, and the composite thermally conductive material layer 200 flows out from the opening of the thermal insulation frame 100.

[0053] It is understood that the shape and material of the heat insulation frame 100 are not specifically limited, as long as at least one side of the heat insulation frame 100 has an opening to allow the composite thermally conductive material layer 200 to flow out when it is in a liquid state. In an optional embodiment, the thermal conductivity of the heat insulation frame 100 is less than that of the composite thermally conductive material layer 200. In an optional embodiment, the thermal conductivity of the heat insulation frame 100 is 0.038 W / (m·K) - 0.07 W / (m·K). The heat insulation frame 100 has a certain strength to separate the two batteries by a certain distance to ensure the heat insulation function. In an optional embodiment, the heat insulation frame 100 is any one or more of aluminum silicate fiberboard, glass fiberboard, mica board, or microporous calcium silicate board.

[0054] It is understood that the composite thermally conductive material layer 200 has different phase transition states under different ambient temperatures. For example, if the phase transition temperature of the composite thermally conductive material layer 200 is 50°C, it is in a solid phase when the ambient temperature is below 50°C, and in a liquid phase when the ambient temperature is above 50°C. The composite thermally conductive material layer 200 fills the receiving cavity 101 of the heat insulation frame 100. When the heat insulation plate 10 is placed between two batteries, the composite thermally conductive material layer 200 directly contacts the battery casing or aluminum-plastic film, providing good thermal conductivity. When the battery operates within its normal temperature range, the composite thermally conductive material layer 200 provides good thermal conductivity, allowing full utilization of the thermal management system for cooling or heating. When the battery operates at temperatures above 50°C, the composite thermally conductive material 200 becomes liquid, increasing the contact area with the battery casing or aluminum-plastic film and thus increasing its thermal conductivity.

[0055] In an optional embodiment, the composite thermally conductive material layer 200 is composed of a mixture of high thermal conductivity powder and a phase change material. The mixing ratio of the high thermal conductivity powder and the phase change material can be arbitrarily set according to the desired phase change temperature. The thermal conductivity of the high thermal conductivity powder is in the range of 3.5 W / (m·K) to 6.0 W / (m·K). In an optional embodiment, the phase change temperature of the composite thermally conductive material layer 200 is 45°C to 60°C. In an optional embodiment, the high thermal conductivity powder is any one or more of copper powder, aluminum powder, or graphite powder, and the phase change material is any one or more of paraffin wax, inorganic hydrated salt, or phase change silicone grease.

[0056] It is understood that, in an optional embodiment, the deformation temperature of the heat-shrinkable film 300 is greater than 80°C. In an optional embodiment, the heat-shrinkable film 300 is any one or more of a plastic polyethylene composite film, a polyolefin heat-shrinkable composite film, or a low-pressure polyethylene composite film. The heat-shrinkable film 300 seals the sides of the thermal insulation frame 100, limiting the leakage of the composite thermally conductive material layer 200. At temperatures above 80°C, it will deform and detach from the sides of the thermal insulation frame 100. At this time, the composite thermally conductive material layer 200 can flow out from the opening of the thermal insulation frame 100. Please refer to [link to details]. Figure 2 When the composite thermally conductive material layer 200 completely flows out from the opening of the thermal insulation frame 100, the average thermal conductivity of the thermal insulation plate 10 decreases, thereby suppressing heat spread.

[0057] In this embodiment, the heat insulation plate 10 includes a heat insulation frame 100, a composite thermally conductive material layer 200, and a heat-shrinkable film 300. The heat insulation frame 100 is a support frame with an opening. The heat-shrinkable film 300 is connected to the opening of the heat insulation frame 100 to surround the heat insulation frame 100 and form a receiving cavity 101. The composite thermally conductive material layer 200 fills the receiving cavity 101. When within the normal temperature range, the composite thermally conductive material layer 200 can provide good thermal conductivity. The composite thermally conductive material layer 200 and the heat insulation frame 100 form at least one contact interface. When the ambient temperature reaches a preset temperature, the heat-shrinkable film 300 deforms and detaches from the opening of the heat insulation frame 100. The composite thermally conductive material layer 200 changes phase to liquid and flows out from the opening of the heat insulation frame 100. At this point, only the heat insulation frame 100 remains of the heat insulation board 10, and the average thermal conductivity of the heat insulation board 10 decreases, thereby suppressing heat spread.

[0058] In an optional embodiment, the thermal insulation frame 100 includes a first crossbeam 110, a connecting beam 120, and a second crossbeam 130.

[0059] The end of the first crossbeam 110 is connected to the heat-shrinkable film 300. One end of the connecting beam 120 is connected to the middle connecting portion of the first crossbeam 110. The middle connecting portion of the second crossbeam 130 is connected to the other end of the connecting beam 120. The end of the second crossbeam 130 is connected to the heat-shrinkable film 300.

[0060] For details, please see Figure 3 The connecting beam 120 is a central connecting beam that divides the heat insulation frame 100 into two symmetrical parts. At this time, the heat insulation frame 100 has two openings, one on the left and one on the right. The heat-shrinkable film 300 can be correspondingly disposed on the left and right sides of the heat insulation frame 100 to form two receiving cavities 101 within the heat insulation frame 100. The two receiving cavities 101 are filled with the composite thermally conductive material layer 200 so that the heat insulation plate 10 can provide good heat dissipation when the battery is operating normally. When the battery is in a thermal runaway state, the heat-shrinkable film 300 deforms, and the composite thermally conductive material layer 200 liquefies and flows out from the openings, reducing the thermal conductivity of the heat insulation plate 10 and thus inhibiting heat spread.

[0061] In an optional embodiment, the first crossbeam 110, the connecting beam 120, and the second crossbeam 130 can be integrally formed. In an optional embodiment, the contact interface formed by the composite thermally conductive material layer 200 and the thermal insulation frame 100 is a curved surface, and the contact interface is along the direction from the connecting beam 120 to the opening of the thermal insulation frame 100, which facilitates the flow of the composite thermally conductive material layer 200. That is, the connection between the connecting beam 120 and the second crossbeam 130 is a smooth curved surface.

[0062] Please see Figure 4 In an optional embodiment, the connecting beam 120 is connected to one side of the first crossbeam 110 and the second crossbeam 130. In this case, the thermal insulation frame 100 has an opening. The heat-shrinkable film 300 can be correspondingly disposed on one side of the thermal insulation frame 100 to form a receiving cavity 101 within the thermal insulation frame 100. The receiving cavity 101 is filled with the composite thermally conductive material layer 200 so that the thermal insulation plate 10 can provide good heat dissipation when the battery is operating normally. When the battery is in a thermal runaway state, the heat-shrinkable film 300 deforms, and the composite thermally conductive material layer 200 liquefies and flows out from the opening, reducing the thermal conductivity of the thermal insulation plate 10 and thus suppressing heat spread.

[0063] In one embodiment, the first crossbeam 110 is provided with an air hole 111, which communicates with the receiving cavity 101. When the composite thermally conductive material layer 200 can flow out from the opening of the thermal insulation frame 100, air enters the receiving cavity 101 through the air hole 111 of the thermal insulation frame 100. At this time, the thermal conductivity of the receiving cavity 101 decreases to the range of 0.015 W / (m·K)-0.17 W / (m·K). This results in a decrease in the average thermal conductivity of the thermal insulation plate 10, thereby suppressing heat spread.

[0064] Please see Figure 5 This application provides a battery module 20 in one embodiment. The battery module 20 includes a plurality of battery cells 400 and a heat insulation plate 10 as described in any of the above embodiments.

[0065] The heat insulation plate 10 is disposed between two adjacent battery cells 400. The heat insulation plate 10 is attached to the two adjacent battery cells 400. The structure and materials of the heat insulation plate 10 are exactly the same as those of the heat insulation plate 10 in the above embodiment, and will not be repeated here. The battery cell 400 can be a lithium-ion battery. The heat insulation frame 100 has a certain strength and is used to separate the two batteries by a certain distance to ensure the heat insulation function. When the battery cell 400 is working normally, the heat insulation plate 10 can play a good heat dissipation function. When the battery cell 400 is in a thermal runaway state, the heat shrink film 300 deforms, and the composite thermally conductive material layer 200 liquefies and flows out from the opening, reducing the thermal conductivity of the heat insulation plate 10, thereby inhibiting heat spread.

[0066] One embodiment of this application provides a battery pack. The battery pack includes multiple battery modules 20 as described in the above embodiments and a housing. The structure and materials of the battery modules 20 are exactly the same as those of the battery modules 20 in the above embodiments, and will not be described again here. The housing assembles the multiple battery modules 20 into a battery pack.

[0067] Please see Figures 6-9 ,like Figure 6 According to the thermal equilibrium simulation results of this application embodiment, when the initial temperature of the first battery is 60°C, the average temperature of the first battery drops to below 45°C within 1227 seconds. Figure 7 The simulation results show the thermal equilibrium when a mica insulating plate of the same thickness is added between the lithium-ion batteries. When the initial temperature of the first battery is 60℃, it takes 3606 seconds for the average temperature of the first battery to drop to 45℃. Figure 6 and Figure 7 The comparison shows that the insulation board 10 of this application has a significant advantage in thermal balance. For example... Figure 8The simulation results show the thermal propagation when the heat-shrink film 300 of this application embodiment does not detach. The results show that the time from thermal runaway of the first lithium-ion battery to thermal runaway of the second lithium-ion battery is approximately 38 seconds. Figure 9 The simulation results show the thermal propagation during the normal detachment of the heat-shrink film 300 according to an embodiment of this application. The results show that the time from thermal runaway of the first lithium-ion battery to thermal runaway of the second lithium-ion battery is approximately 2316 seconds, indicating a significant suppression effect.

[0068] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A thermal barrier plate characterized by, include: A thermal insulation frame (100) forms a support frame with an opening; the thermal insulation frame (100) is used to separate two battery cells (400) to ensure thermal insulation function; A heat-shrinkable film (300) is connected to the opening of the heat insulation frame (100) to surround the heat insulation frame (100) and form a receiving cavity (101); and A composite thermally conductive material layer (200) is filled in the receiving cavity (101), and the composite thermally conductive material layer (200) forms at least one contact interface with the thermal insulation frame (100); the heat shrink film (300) is on the side of the thermal insulation frame (100) to seal the side and limit the leakage of the composite thermally conductive material layer (200), and will deform and fall off from the side of the thermal insulation frame (100) at a temperature above 80°C; When the ambient temperature reaches the preset temperature, the heat shrink film (300) deforms and falls off from the opening of the heat insulation frame (100), the composite thermal conductive material layer (200) changes phase to liquid, and the composite thermal conductive material layer (200) flows out from the opening of the heat insulation frame (100). The thermal insulation frame (100) includes a first crossbeam (110), a connecting beam (120), and a second crossbeam (130); the contact interface formed between the composite thermally conductive material layer (200) and the thermal insulation frame (100) is a curved surface, and the contact interface is along the direction from the connecting beam (120) to the opening of the thermal insulation frame (100) to facilitate the flow of the composite thermally conductive material layer (200); the connection between the connecting beam (120) and the second crossbeam (130) is a smooth curved surface. The connecting beam (120) divides the heat insulation frame (100) into two symmetrical parts. The heat insulation frame (100) has two openings. The heat shrink film (300) is disposed on the left and right sides of the heat insulation frame (100) to form two receiving cavities (101) in the heat insulation frame (100). The composite thermally conductive material layer (200) is filled in the cavity (101) of the heat insulation frame (100). When the heat insulation plate is placed between two battery cells (400), the composite thermally conductive material layer (200) directly contacts the outer shell or aluminum-plastic film of the battery cell (400) to achieve good thermal conductivity. When the battery cell (400) is operating within the normal temperature range, the composite thermally conductive material layer (200) plays a good role in thermal conduction, and the thermal management system is used for cooling or heating. When the battery cell (400) operates at a temperature above 50 degrees Celsius, the composite thermally conductive material becomes liquid, and the contact area with the outer shell or aluminum-plastic film of the battery cell (400) increases, thereby increasing the thermal conductivity.

2. The heat insulation board according to claim 1, characterized in that, The thermal insulation frame (100) includes: The first crossbeam (110) has its end connected to the heat-shrinkable film (300); A connecting beam (120), one end of which is connected to the middle connecting portion of the first crossbeam (110); and The second crossbeam (130) has its middle connecting portion connected to the other end of the connecting beam (120), and the end of the second crossbeam (130) is connected to the heat shrink film (300).

3. The heat insulation board according to claim 2, characterized in that, The first crossbeam (110) is provided with an air hole (111), which is connected to the receiving cavity (101).

4. The heat insulation board according to claim 2, characterized in that, The contact interface is a curved surface, and the contact interface is along the direction from the connecting beam (120) to the opening of the thermal insulation frame (100), which facilitates the flow of the composite thermally conductive material layer (200).

5. The heat insulation board according to claim 1, characterized in that, The composite thermally conductive material layer (200) is composed of a mixture of high thermal conductivity powder and phase change material.

6. The heat insulation board according to claim 5, characterized in that, The high thermal conductivity powder is any one or more of copper powder, aluminum powder, or graphite powder, and the phase change material is any one or more of paraffin wax, inorganic hydrated salt, or phase change silicone grease.

7. The heat insulation board according to claim 1, characterized in that, The thermal insulation frame (100) is any one or more of aluminum silicate fiberboard, glass fiberboard, mica board or microporous calcium silicate board.

8. The heat insulation board according to claim 1, characterized in that, The heat shrink film (300) is any one or more of plastic polyethylene composite film, polyolefin heat shrink composite film, or low-pressure polyethylene composite film.

9. The heat insulation board according to claim 1, characterized in that, The phase transition temperature of the composite thermally conductive material layer (200) is 45°C to 60°C, and the deformation temperature of the heat-shrinkable film (300) is greater than 80°C.

10. A battery module, characterized in that, include: Multiple battery cells (400). The heat insulation plate (10) according to any one of claims 1-9 is disposed between two adjacent battery cells (400).

11. A battery pack, characterized in that, include: The battery module (20) as described in multiple claims 10.

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