A battery assembly and a vehicle

Abstract

The application discloses a battery assembly and a car, and provides the battery assembly, which comprises a box body, a plurality of battery cells are arranged in the box body, the plurality of battery cells are sequentially and spacedly distributed along a direction of the box body, and an even-temperature sheet is arranged between adjacent battery cells. A liquid cooling plate is arranged at the bottom of the battery cell, the liquid cooling plate cools and lowers the temperature of the battery cell, and heat conduction is conducted through the even-temperature sheet, so that the temperature difference between the bottom and the top of the single battery cell is reduced, and the cooling effect is improved. The even-temperature sheet comprises a first layer and a second layer which are nested with each other, the second layer is wrapped outside the first layer, the heat conduction performance of the even-temperature sheet is improved through the composite wrapping structure, the even-temperature sheet can cover the side surface of the battery cell, the temperature difference between the bottom and the top of the single battery cell is further reduced, the cooling effect of the battery is improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] This application relates to the field of new energy battery technology, and more specifically, to a battery assembly and a vehicle. Background Technology

[0002] With the continuous development of new energy vehicles, the use of batteries has become increasingly widespread. As the number of charge and discharge cycles of batteries increases during vehicle operation, the cooling requirements for batteries are gradually increasing. In existing technologies, power battery cells are usually cooled by coolant. However, current liquid cooling plates are usually placed at the bottom of the battery cell, resulting in a large temperature difference between the bottom and top of the battery cell, which leads to poor cooling effect and affects the battery's lifespan.

[0003] In conclusion, improving battery cooling and extending battery life are problems that urgently need to be solved by those skilled in the art. Utility Model Content

[0004] In view of this, the purpose of this application is to provide a battery assembly and an automobile that improves the cooling effect of the battery and extends the battery's service life.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A battery assembly includes: a housing with an accommodating space; a battery cell located within the housing, comprising a plurality of cells spaced apart sequentially along one direction of the housing, with a heat spreader disposed between adjacent cells; and a liquid cooling plate located within the housing and disposed at the bottom of the battery cell; wherein the heat spreader comprises a nested first layer and a second layer, the second layer covering the outside of the first layer, and the heat spreader covering the side of the battery cell.

[0007] In some embodiments, the thickness of the temperature distribution plate is 1.2 mm.

[0008] In some embodiments, the first layer is a thermally resistive porous plate, and the thermally resistive porous plate has channels formed inside for the flow of a homogenizing liquid.

[0009] In some embodiments, the thermal resistance porous plate is one of polyethylene foam board, polypropylene foam board, polyurethane foam board, silicone rubber foam board, and porous ceramic board.

[0010] In some embodiments, the isothermal liquid is one of silicone oil, perfluoropolyether oil, Novec hydrofluoroether, and ethylene glycol aqueous solution.

[0011] In some embodiments, the second layer is a double-layer thin film structure, the inner layer of the second layer is a thermally conductive layer, and the outer layer of the second layer is an insulating layer.

[0012] In some embodiments, the thermally conductive layer is one of an aluminum foil layer and a copper foil layer.

[0013] In some embodiments, the insulating layer is one of a resin layer and a polyimide layer.

[0014] In some embodiments, the housing includes an upper cover and a lower cover, the upper cover and the lower cover being detachably fixed together by threaded fasteners, and a sealing layer is provided between the upper cover and the lower cover.

[0015] In some embodiments, both the upper cover and the lower cover are made of long glass fiber substrate composite material.

[0016] In some embodiments, the liquid cooling plate includes at least two liquid cooling channels; the liquid cooling plate is bonded to the bottom surface of the battery cell by thermally conductive structural adhesive.

[0017] An automobile includes a battery assembly as described above.

[0018] The battery assembly provided in this application includes a housing, in which a plurality of battery cells are placed, and the plurality of battery cells are distributed sequentially at intervals along one direction of the housing. A heat spreader is provided between adjacent battery cells, and a liquid cooling plate is provided at the bottom of the battery cells. The liquid cooling plate cools the battery cells and conducts heat through the heat spreader to reduce the temperature difference between the bottom and top of a single battery cell and improve the cooling effect. The heat spreader includes a first layer and a second layer that are nested together. The second layer covers the outside of the first layer. The composite covering structure improves the heat conduction performance of the heat spreader, and the heat spreader can cover the sides of the battery cells, further reducing the temperature difference between the bottom and top of a single battery cell, thereby improving the cooling effect of the battery and extending the battery's service life. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the battery assembly provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the internal structure of the battery assembly provided in an embodiment of this application;

[0022] Figure 3 A schematic diagram showing the interaction between the battery cell and the heat spreader in the battery assembly provided in the embodiments of this application;

[0023] Figure 4 A schematic diagram showing the interaction between the battery cell and the liquid cooling plate in the battery assembly provided in this application embodiment;

[0024] Figure 5 A schematic diagram of the liquid cooling plate in the battery assembly provided in this application embodiment;

[0025] Figure 6 A comparison of the temperature difference between the bottom and top of a battery cell with and without a heat exchanger in the battery assembly, and with a heat exchanger with a thickness of 1.2mm added.

[0026] Figure 7 A comparison chart showing the temperature difference between adjacent cells in a battery assembly with and without a heat exchanger, and with a heat exchanger having a thickness of 1.2mm.

[0027] Figure 8 A comparison of the temperature difference between the bottom and top of a battery cell with and without a 1mm thick heat spreader in the battery assembly.

[0028] Figure 9 The fire resistance test results of the box material provided in the embodiments of this application are shown in the figure.

[0029] Figure 10 A comparison diagram of the temperature difference between the inside and outside of the battery pack in the case of thermal runaway, provided in the embodiments of this application.

[0030] Explanation of reference numerals in the attached figures:

[0031] 100 - Box body, 110 - Top cover, 120 - Bottom cover;

[0032] 200-cell;

[0033] 300-Population Plate;

[0034] 400 - Liquid cooling plate, 410 - Liquid cooling channel. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to be a limitation of this application. As used in the specification and appended claims of this application, the singular expressions "a," "an," "the," "the," "the," and "this" are intended to also include expressions such as "one or more," unless the context clearly indicates otherwise. It should also be understood that in the embodiments of this application, "one or more" refers to one, two, or more; "and / or" describes the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0037] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0038] The "multiple" mentioned in the embodiments of this application refers to two or more. It should be noted that in the description of the embodiments of this application, terms such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0039] like Figures 1-2As shown, the battery assembly provided in this application embodiment includes a housing 100, which forms an accommodating space to allow various components to be placed inside the housing 100; battery cells 200, which are located inside the housing 100, and there are several battery cells 200. The several battery cells 200 are sequentially spaced along one direction of the housing 100, which can be along the length or width direction of the housing 100, and a heat spreader 300 is provided between adjacent battery cells 200. A liquid cooling plate 400 is also provided inside the housing 100. At the bottom of the battery cell 200, the liquid cooling plate 400 is used to cool the battery cell 200 and the heat is conducted through the heat spreader 300 to reduce the temperature difference between the bottom and top of the individual battery cell 200 and improve the cooling effect. The heat spreader 300 includes a first layer and a second layer nested together. The second layer covers the outside of the first layer and the heat spreader 300 can cover the entire side of the battery cell 200 to further reduce the temperature difference between the bottom and top of the individual battery cell 200, thereby improving the cooling effect of the battery and extending the battery's lifespan.

[0040] It should be noted that, as Figure 3 As shown, the heat spreader 300 is adhesively bonded to the side of adjacent cells 200 to improve the stability of the connection between the cells 200 and the heat spreader 300, ensuring stable operation of the battery assembly. Simultaneously, since dimensional deviations between cells 200 may occur during actual assembly, resulting in uneven gaps between cells 200, the heat spreader 300 is placed between adjacent cells 200 to compensate for these dimensional deviations, facilitating battery assembly and further securing the cells 200.

[0041] In this application, the first layer of the heat spreader 300 is a thermal resistance porous plate, and the thermal resistance porous plate has channels for the flow of heat spreader liquid. The high thermal conductivity of the heat spreader liquid improves the heat conduction between the cells 200, thereby reducing the temperature difference between the bottom and top of the cells 200. At the same time, in the event of thermal runaway of a single cell 200 due to excessive temperature, the heat spreader liquid in the thermal resistance porous plate will vaporize and release gas, thereby insulating and cooling the adjacent cells 200, reducing the thermal runaway of the entire battery module caused by the thermal runaway of a single cell 200, and improving the safety of the battery assembly during operation.

[0042] It should be noted that the thermal resistance porous plate is a porous structure with a certain strength, high thermal resistance, and internal channels to provide structural support and flow channels for the homogenizing liquid, so that the homogenizing liquid flows in the thermal resistance porous plate to conduct heat and reduce the temperature difference of the battery cell 200.

[0043] In some embodiments, the thermal resistance porous plate is a polymer porous material plate, such as polyethylene foam board, polypropylene foam board, polyurethane foam board, silicone rubber foam board, etc., which is easy to process into a sheet structure with multiple channels, and has good chemical stability, good flame retardancy, and can provide good support strength.

[0044] In other embodiments, the thermal resistance porous plate can also be a porous ceramic material plate with high temperature resistance and high chemical inertness to further improve the flame retardant performance of the thermal resistance porous plate.

[0045] In this application, the temperature-equalizing liquid is a liquid with a high thermal conductivity and a suitable boiling point. The temperature-equalizing liquid exists in the channels of the thermal resistance porous plate. When the temperature rises in a certain local area, the temperature-equalizing liquid can absorb heat and conduct heat, or it can further reach the boiling point of the temperature-equalizing liquid. Through the vaporization-evaporation-condensation cycle mechanism of the temperature-equalizing liquid, heat is quickly transferred from the high temperature point to the low temperature point, thereby improving the temperature uniformity of the entire thermal resistance porous plate and achieving the effect of temperature equalization.

[0046] In some embodiments, the temperature homogenizing liquid can be silicone oil, which has good thermal stability, a wide viscosity range, is non-toxic, and can be selected with a lower viscosity to increase fluidity, thereby improving heat transfer efficiency through the flow of silicone oil and thus improving temperature homogenization performance.

[0047] In other embodiments, the temperature equalization liquid can be a perfluoropolyether oil, which has strong chemical inertness, can stably conduct heat, and has excellent insulation properties, thereby improving the stability of the heat conduction process.

[0048] In some other embodiments, the homogenizing liquid can be Novec hydrofluoroether, which is highly safe, can achieve two-phase heat conversion, and has high heat transfer efficiency, thereby improving the homogenization efficiency and further ensuring the operational safety of the battery cell 200.

[0049] In other embodiments, the temperature equalization liquid can be a coolant such as an aqueous solution of ethylene glycol, which can achieve heat transfer and cooling, further improving the cooling effect and temperature equalization efficiency.

[0050] It should be noted that Novec hydrofluoroether is a high-performance fluorinated liquid that is environmentally friendly, highly safe, and has excellent thermal stability. It also has low surface tension and low viscosity, which makes it easier to penetrate into tiny pores and further improve the temperature uniformity of the temperature uniform plate 300.

[0051] In this application, the second layer of the heat spreader 300 has a double-layer thin film structure, with the inner layer being a thermally conductive layer and the outer layer being an insulating layer. The second layer encloses and seals the thermally resistive porous plate of the first layer, forming an independently sealed heat spreader 300, reducing liquid leakage and external contamination, and ensuring the safe use of the heat spreader 300.

[0052] Furthermore, the heat-conducting layer enables heat transfer between the homogenizing liquid inside the thermal resistance porous plate and the battery cell 200, thereby improving the homogenization efficiency.

[0053] In some embodiments, the thermally conductive layer is an aluminum foil layer, which can provide excellent planar thermal conductivity to improve heat transfer efficiency, thereby improving temperature uniformity and extending the service life of the battery cell 200.

[0054] In other embodiments, the thermally conductive layer may also be a copper foil layer, which has excellent thermal conductivity, to further improve the temperature uniformity of the plane.

[0055] In some embodiments, the insulating layer is a resin layer that provides a certain support strength and has electrical insulation and sealing properties to ensure the stable operation of the temperature equalizer 300.

[0056] In other embodiments, the insulating layer may also be a polyimide layer, which has good high temperature resistance, good mechanical strength, and good insulation properties to ensure the stable operation of the temperature equalizer 300.

[0057] like Figure 2 As shown, the housing 100 includes an upper cover 110 and a lower cover 120, and the upper cover 110 and the lower cover 120 are detachably fixedly connected by threaded fasteners. A sealing layer is provided between the upper cover 110 and the lower cover 120 so that the housing 100 forms a relatively sealed accommodating space, improving dustproof and waterproof performance and further improving the service life of the battery assembly.

[0058] In this application, both the upper cover 110 and the lower cover 120 are made of long glass fiber substrate composite material. Specifically, both the upper cover 110 and the lower cover 120 are made of composite material based on long glass fiber substrate with added flame retardants to improve the fire resistance of the upper cover 110 and the lower cover 120. At the same time, they have the advantages of being lightweight and having high insulation to improve the flame retardant performance of the housing 100 and improve the safety of battery assembly operation.

[0059] like Figures 4-5 As shown in the present application, the liquid cooling plate 400 includes at least two liquid cooling channels 410, so that the coolant can flow through the liquid cooling channels 410 to circulate throughout the liquid cooling plate 400, thereby achieving cooling of the battery cell 200.

[0060] In this application, the liquid cooling plate 400 is bonded to the bottom surface of the battery cell 200 by thermally conductive structural adhesive, which ensures the connection stability between the liquid cooling plate 400 and the battery cell 200, improves the heat exchange efficiency between the liquid cooling plate 400 and the battery cell 200, and further extends the service life of the battery cell 200.

[0061] like Figure 6As shown, the temperature difference between the bottom and top of a single battery cell 200 with and without a heat spreader 300 provided in this embodiment was tested. It can be seen that without a heat spreader, the maximum temperature difference between the bottom and top of the single battery cell 200 can reach 4.4℃, and the temperature difference generally increases over time. With the heat spreader 300 provided in this embodiment, and the thickness of the heat spreader 300 being 1.2mm, the maximum temperature difference between the bottom and top of the single battery cell 200 is 0.91℃, and the temperature difference tends to be stable. Therefore, by setting a heat spreader 300 between adjacent battery cells 200, the temperature difference between the bottom and top of the single battery cell 200 can be significantly reduced, and the overall temperature trend of the battery cell 200 can be kept stable, improving the cooling effect of the battery cell 200 and extending its service life.

[0062] like Figure 7 As shown, the temperature difference between adjacent cells 200 without a temperature equalizer and with the temperature equalizer 300 provided in this embodiment was tested. It can be seen that without the temperature equalizer, the maximum temperature difference between adjacent cells 200 is 1.14℃, while with the temperature equalizer 300 provided in this embodiment, the maximum temperature difference between adjacent cells 200 is 0.91℃. Therefore, by setting the temperature equalizer 300 provided in this embodiment, the temperature difference between adjacent cells 200 can also be balanced, thereby further improving the overall cooling effect of the battery and extending the battery's service life.

[0063] like Figure 8 As shown, the temperature difference between the bottom and top of a single battery cell 200 was tested after setting a 1mm and a 1.2mm temperature equalizer 300. It can be seen that with the 1mm temperature equalizer 300, the maximum temperature difference between the bottom and top of the single battery cell 200 is 2.1℃, and the temperature difference shows a slight upward trend. With the 1.2mm temperature equalizer 300, the maximum temperature difference between the bottom and top of the single battery cell 200 is 0.91℃, and the temperature difference tends to be stable. Therefore, it can be seen that with a temperature equalizer 300 thickness of 1.2mm, the temperature difference between the bottom and top of the single battery cell 200 can be significantly reduced, and the temperature difference tends to be stable. Therefore, in this embodiment, the preferred thickness of the temperature equalizer 300 is 1.2mm to further improve the cooling effect on the battery.

[0064] like Figure 9As shown, a fire test was conducted on the material of the housing 100 provided in this application embodiment. It can be seen that, under the composite material of long glass fiber substrate with added flame retardant provided in this application embodiment, the interior of the material was continuously burned, and the temperature inside the material was maintained at 1200°C, while the exterior of the material was still maintained at 200°C. After burning for 30 minutes, there was still a high temperature difference between the inside and outside of the material. Therefore, it can be seen that the material did not burn through after burning for 30 minutes, and the high temperature was maintained inside the material. It can be seen that the long glass fiber substrate composite material used in the housing 100 of this application has excellent flame retardancy and can improve the safety of the battery assembly during operation.

[0065] like Figure 10 As shown, a thermal runaway test was performed on the battery assembly provided in this application. In the event of thermal runaway in the cell 200 inside the housing 100, [the following information is provided]. Figure 10 It can be seen that due to thermal runaway, the internal temperature of the housing 100 rises sharply to 980°C, and then gradually decreases to the same temperature as the outside of the housing 100. Meanwhile, the outside of the housing 100 remains stable at a temperature below 200°C. Therefore, the housing 100 has a good heat insulation effect, which can reduce the impact of thermal runaway of the battery cell 200 on other structures outside the battery assembly and improve the overall safety performance of the vehicle.

[0066] The battery assembly provided in this application embodiment reduces the temperature difference between the bottom and top of a single cell 200 by setting a heat spreader 300 between adjacent cells 200, thereby improving the cooling effect of the battery. At the same time, by setting the material of the housing 100 as a composite material with long glass fiber substrate, the flame retardant performance of the housing 100 is improved, the reliability of the housing 100 is further improved, and the service life of the battery assembly is extended.

[0067] This application also provides a vehicle that includes the battery assembly described in the above embodiments.

[0068] Since the battery assembly described above has the aforementioned technical effects, and the vehicle described above includes the battery assembly, the vehicle also has the corresponding technical effects, which will not be elaborated here.

[0069] The above description of the embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery assembly, characterized in that, include: A housing (100) having an accommodating space within it; A battery cell (200) is located inside the housing (100). There are several battery cells (200), and the several battery cells (200) are distributed sequentially at intervals along one direction of the housing (100). A heat spreader (300) is provided between adjacent battery cells (200). A liquid cooling plate (400) is located inside the housing (100) and is disposed at the bottom of the battery cell (200); The temperature distribution plate (300) includes a first layer and a second layer nested together, the second layer covering the outside of the first layer, and the temperature distribution plate (300) covering the side of the battery cell (200).

2. The battery assembly according to claim 1, characterized in that, The thickness of the temperature equalization plate (300) is 1.2 mm.

3. The battery assembly according to claim 1, characterized in that, The first layer is a thermally resistive porous plate, and the thermally resistive porous plate has channels formed inside for the flow of homogenizing liquid.

4. The battery assembly according to claim 3, characterized in that, The thermal resistance porous plate is one of polyethylene foam board, polypropylene foam board, polyurethane foam board, silicone rubber foam board, and porous ceramic board.

5. The battery assembly according to claim 3, characterized in that, The homogenizing liquid is one of silicone oil, perfluoropolyether oil, Novec hydrofluoroether, or ethylene glycol aqueous solution.

6. The battery assembly according to claim 1, characterized in that, The second layer has a double-layer thin film structure, with the inner layer being a thermally conductive layer and the outer layer being an insulating layer.

7. The battery assembly according to claim 6, characterized in that, The thermally conductive layer is either an aluminum foil layer or a copper foil layer.

8. The battery assembly according to claim 6, characterized in that, The insulating layer is one of a resin layer or a polyimide layer.

9. The battery assembly according to claim 1, characterized in that, The housing (100) includes an upper cover (110) and a lower cover (120), the upper cover (110) and the lower cover (120) being detachably fixedly connected by threaded fasteners, and a sealing layer is provided between the upper cover (110) and the lower cover (120).

10. The battery assembly according to claim 9, characterized in that, Both the upper cover (110) and the lower cover (120) are made of long glass fiber substrate composite material.

11. The battery assembly according to claim 1, characterized in that, The liquid cooling plate (400) includes at least two liquid cooling channels (410). The liquid cooling plate (400) is bonded to the bottom surface of the battery cell (200) by thermally conductive structural adhesive.

12. A car, characterized in that, Includes the battery assembly as described in any one of claims 1-11.

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