Battery module, design method thereof and vehicle

Abstract

The invention provides a battery module, a design method thereof and a vehicle. A design method of a battery module comprises the steps that a battery module model is established, the battery module model comprises a battery pack and a liquid cooling plate, the battery pack comprises a plurality of single batteries, each single battery comprises a shell and an insulating film, the outer surface of the shell is coated with the insulating film, and the liquid cooling plate is arranged in the shell; the insulating film is provided with an initial heat dissipation window penetrating in the thickness direction of the insulating film, and the liquid cooling plate is attached to the outer surface of the insulating film and covers the initial heat dissipation window; performing thermal simulation processing on the battery module model according to working conditions of the battery module model to obtain an initial simulation result; and determining the area of a target heat dissipation window of each single battery according to the initial simulation result. According to the scheme, the heat dissipation capability of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery heat dissipation, and more specifically, to a battery module, a design method thereof, and a vehicle. Background Art

[0002] Due to the improvement of environmental protection awareness and the crisis of petroleum energy, lithium-ion batteries have attracted much attention due to their advantages such as high energy density, long cycle life, and environmental friendliness.

[0003] Among them, square aluminum shell lithium-ion batteries are widely used due to their advantages such as low cost, light weight, and good ductility. In order to prevent electrochemical corrosion of the aluminum shell, the current method is to conduct the positive electrode of the battery to the cover plate so that the potentials of the positive electrode and the aluminum shell tend to be the same. Since the aluminum shell is electrically connected to the positive electrode, potential insulation failure may occur during use. In order to prevent a short-circuit loop from forming between the batteries, an insulating film is usually coated outside the aluminum shell.

[0004] However, the insulating film is a poor conductor of heat. After connecting the battery to the liquid cooling plate, the insulating film greatly reduces the heat exchange efficiency between the battery and the liquid cooling plate, thereby reducing the heat dissipation capacity of the battery. Summary of the Invention

[0005] The present application provides a battery module, a design method thereof, and a vehicle, which can improve the heat dissipation capacity of the battery.

[0006] A design method of a battery module includes: establishing a battery module model, the battery module model including a battery pack and a liquid cooling plate, the battery pack including a plurality of single batteries, each single battery including a housing and an insulating film, the insulating film covering the outer surface of the housing, the insulating film being provided with an initial heat dissipation window penetrating in the thickness direction of the insulating film, the liquid cooling plate being attached to the outer surface of the insulating film and covering the initial heat dissipation window; performing a thermal simulation process on the battery module model according to the working condition conditions of the battery module model to obtain an initial simulation result; and determining the area of the target heat dissipation window of each single battery according to the initial simulation result.

[0007] Optionally, the initial simulation result at least includes the temperature of each single battery and the average temperature of the plurality of single batteries;

[0008] The determining the area of the target heat dissipation window of each single battery according to the initial simulation result includes:

[0009] Determining the area of the target heat dissipation window of each single battery according to the temperature of each single battery and the average temperature.

[0010] Optionally, the multiple single cells include a first single cell to an nth single cell, and the first single cell to the nth single cell are configured to be sequentially distributed along the flow direction of the coolant in the liquid cooling plate, where n is greater than or equal to 2;

[0011] Determining the area of the target heat dissipation window for each single cell according to the temperature of each single cell and the average temperature further includes:

[0012] According to the temperature of the first single cell and the average temperature, gradually adjust the initial heat dissipation window area of the first single cell. According to the principle of heat balance, calculate the difference between the temperature of the first single cell after each adjustment and the average temperature until the difference between the temperature of the first single cell and the average temperature reaches a preset convergence condition, and then determine the area of the target heat dissipation window of the first single cell;

[0013] Repeat the above steps until the differences between the temperatures of the second single cell to the nth single cell and the average temperature all reach the preset convergence condition, and then determine the areas of the target heat dissipation windows of the second single cell to the nth single cell.

[0014] Optionally, the multiple single cells include a first single cell to an nth single cell, and the first single cell to the nth single cell are configured to be sequentially distributed along the flow direction of the coolant in the liquid cooling plate, where n is greater than or equal to 2;

[0015] Determining the area of the target heat dissipation window for each single cell according to the initial simulation result further includes:

[0016] When the temperatures of the first single cell to the nth single cell are all equal to the average temperature, according to the difference between the temperature of each single cell and the average temperature and the principle of heat balance, sequentially calculate the areas of the target heat dissipation windows of the first single cell to the nth single cell; according to the calculation results, determine the areas of the target heat dissipation windows of the first single cell to the nth single cell.

[0017] Optionally, the principle of heat balance is: heat dissipation of the single cell = interfacial heat exchange amount = heat absorption amount of the liquid cooling plate;

[0018] The heat dissipation of the single cell = ΔT1C1 + Q; ΔT1 is the temperature change of the single cell, C1 is the heat capacity of the single cell, and Q is the heat generation of the single cell;

[0019] The interfacial heat flux = ΔT2(S1K1 + S2K2); ΔT2 is the temperature difference between the single battery and the liquid cooling plate, S1 is the contact area between the insulating film and the liquid cooling plate, K1 is the heat transfer coefficient between the insulating film and the liquid cooling plate, S2 is the area of the heat dissipation window, K2 is the heat transfer coefficient between the housing and the liquid cooling plate, where S1 + S2 is equal to the contact area S between the single battery and the liquid cooling plate;

[0020] The heat absorption of the liquid cooling plate = ΔT3C2L; C2 is the specific heat capacity of the coolant in the liquid cooling plate, and L is the mass flow rate of the coolant.

[0021] A battery module designed by any of the above methods, the battery module includes a battery pack and a liquid cooling plate, the battery pack includes a plurality of single batteries, each single battery includes a housing and an insulating film, the insulating film covers the outer surface of the housing, and the insulating film is provided with a heat dissipation window penetrating along the thickness direction of the insulating film, and the liquid cooling plate is attached to the outer surface of the insulating film and covers the heat dissipation window.

[0022] Optionally, the plurality of single batteries include a first single battery to an nth single battery, and the first single battery to the nth single battery are configured to be distributed in sequence along the flow direction of the coolant in the liquid cooling plate; along the flow direction of the coolant, the area of the heat dissipation window of the first single battery to the area of the heat dissipation window of the nth single battery gradually increases.

[0023] Optionally, the heat exchange amount between each single battery and the liquid cooling plate is equal.

[0024] A vehicle includes the battery module according to any of the above. Description of the Drawings

[0025] Figure 1 is a flowchart of a design method of a battery module shown in an exemplary embodiment of the present application;

[0026] Figure 2 is a schematic structural diagram of a single battery shown in an exemplary embodiment of the present application;

[0027] Figure 3 is a bottom view of the single battery;

[0028] Figure 4 is a side view of the single battery;

[0029] Figure 5 is a schematic connection structure diagram of a single battery and a liquid cooling plate shown in an embodiment;

[0030] Figure 6 is a schematic structural diagram of a plurality of single batteries;

[0031] Figure 7 is a schematic structural diagram of a battery module shown in one embodiment;

[0032] Figure 8 is a schematic structural diagram of a battery module shown in another embodiment.

[0033] Explanation of reference numerals: 10, single battery; 11, insulating film; 111, safety edge; 12, heat dissipation window; 13, housing; 14, thermal conductive adhesive layer; 15, insulating film folded edge; 20, liquid cooling plate; 21, first liquid cooling plate; 22, second liquid cooling plate. Detailed implementation manners

[0034] Here, exemplary embodiments will be described in detail, and examples are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application.

[0035] The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. Unless otherwise defined, the technical terms or scientific terms used in the present application should have the ordinary meanings understood by those of ordinary skill in the art to which the present application belongs. The "first", "second" and similar terms used in the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, the terms such as "a" or "one" do not indicate a quantity limitation, but indicate that there is at least one. If only referring to "one", it will be separately stated. "Multiple" or "several" means two or more. Unless otherwise indicated, the terms such as "front part", "rear part", "lower part" and / or "upper part", "top", "bottom" are only for convenience of description and are not limited to one position or a spatial orientation. The terms such as "including" or "comprising" mean that the elements or objects appearing before "including" or "comprising" cover the elements or objects listed after "including" or "comprising" and their equivalents, and do not exclude other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect.

[0036] The embodiments of the present application provide a battery module, its design method, and a vehicle. The battery module, its design method, and the vehicle will be described in detail below with reference to the accompanying drawings. Without conflict, the features in the following embodiments and implementation manners can be combined with each other.

[0037] Reference Figure 1As shown in the figure, an embodiment of the present application provides a design method for a battery module, including:

[0038] S101, establishing a battery module model;

[0039] Among them, the battery module model includes a battery pack and a liquid cooling plate. The battery pack includes a plurality of single cells. Each single cell includes a housing and an insulating film. The insulating film is coated on the outer surface of the housing. The insulating film is provided with an initial heat dissipation window penetrating along the thickness direction of the insulating film. The liquid cooling plate is attached to the outer surface of the insulating film and covers the initial heat dissipation window. The initial heat dissipation window can be set according to actual conditions. The initial heat dissipation window can be set on the bottom surface of the single cell or on the side surface of the single cell. The area of the initial heat dissipation window should not be too large or too small. For example, when the initial heat dissipation window is set on the first surface of the single cell, the area of the initial heat dissipation window can be 20% to 80% of the area of the first surface. The first surface can be the side surface of the single cell or the bottom surface of the single cell, but it is not limited thereto.

[0040] It should be noted that the heat exchange area between the single cell and the liquid cooling plate is S. Specifically, this heat exchange area S is divided into two parts. The first part is the heat exchange area S1 between the single cell and the liquid cooling plate through the heat dissipation window of the insulating film, and the second part is the heat exchange area S2 between the single cell and the liquid cooling plate through the heat dissipation window. S1 + S2 = S. And, it is easy to understand that the insulating film is a poor conductor of heat. When the heat exchange area S is certain, the larger the area S2 of the heat dissipation window (until S2 = S), the more heat exchange between the single cell and the liquid cooling plate, that is, the better the heat dissipation of the single cell, and the lower its temperature during operation.

[0041] S102. Perform thermal simulation on the battery module model according to the operating conditions of the battery module model to obtain an initial simulation result. The operating conditions are the conditions when the battery module is discharging under normal operation, and it can also be the conditions when the battery module is charging. In this embodiment, the charging and discharging rates of the battery module are not specifically limited, and those skilled in the art can set them according to requirements. The normal temperature of each single battery can be set according to requirements. For example, the initial temperature (not charged or discharged) of each single battery can be set to 25°C, but it is not limited thereto. In some other embodiments, the initial temperature of the single battery can be 15°C, 18°C, 20°C, 22°C, etc. Similarly, the temperature of the coolant in the liquid cooling plate can be set to 5°C, but it is not limited thereto. In some other embodiments, the temperature of the coolant can be 0°C, 2°C, 8°C, 10°C, 15°C, etc. Among them, the specific heat capacity C2 and mass flow rate L of the coolant in the liquid cooling plate can be set as needed. The heat transfer coefficient K1 between the insulating film and the liquid cooling plate and the heat transfer coefficient K2 between the housing and the liquid cooling plate are also related to the materials of the insulating film and the liquid cooling plate. This application does not make specific limitations on these, but it is easy to understand that the above-mentioned are all known quantities.

[0042] S103. Determine the area of the target heat dissipation window for each single battery according to the initial simulation result. In this way, the overall heat dissipation situation of the battery pack can be judged based on the initial simulation result, and the area of the target heat dissipation window for each single battery can be determined according to actual requirements. For example, the initial simulation result at least includes the average temperature of multiple single batteries. When the average temperature of multiple single batteries is higher than the preset average temperature, the area of the heat dissipation window of at least one of the multiple single batteries can be appropriately enlarged to obtain the area of the target heat dissipation window. Or, the initial simulation result can also include the temperature of each single battery. When the average temperature of multiple single batteries is lower than the preset average temperature, but the uniformity of the temperatures of multiple single batteries is poor, that is, there are some single batteries with a large difference between their temperatures and the average temperature, the initial heat dissipation window areas of these single batteries can be adaptively adjusted to obtain the area of the target heat dissipation window. Or, when the temperature of each single battery and the average temperature of multiple single batteries both meet the preset requirements, the initial heat dissipation window of the single battery is the target heat dissipation window.

[0043] In one embodiment, the initial simulation result at least includes the temperature of each single battery and the average temperature of multiple single batteries. Step S103, determining the area of the target heat dissipation window for each single battery according to the initial simulation result, includes:

[0044] Determine the area of the target heat dissipation window for each single battery according to the temperature and average temperature of each single battery.

[0045] That is, the user can determine the area of the target heat dissipation window for each single battery by calculating the difference between the temperature of each single battery and the average temperature. When the temperature of the single battery is approximately equal to the average temperature, the initial heat dissipation window area of the single battery is the target heat dissipation window area. When the temperature of the single battery is lower than the average temperature, the user can reduce the area of the initial heat dissipation window of the single battery, and the specific reduction range can be determined according to the specific difference between the single battery and the average temperature. When the temperature of the single battery is higher than the average temperature, the user can increase the temperature of the initial heat dissipation window of the single battery, and the specific increase range can be determined according to the specific difference between the single battery and the average temperature. That is to say, given the temperature and average temperature of each single battery, the user can adjust the area of the initial heat dissipation window of the single battery according to experience or some specific algorithms.

[0046] In one embodiment, the plurality of single batteries include a first single battery to an nth single battery, and the first single battery to the nth single battery are configured to be sequentially distributed along the flow direction of the coolant in the liquid cooling plate; where n is greater than or equal to 2, that is, there are at least two single batteries.

[0047] Determining the area of the target heat dissipation window for each single battery according to the temperature and average temperature of each single battery includes:

[0048] According to the temperature of the first single battery and the average temperature, using the step-by-step analysis method, gradually adjust the area of the initial heat dissipation window of the first single battery, and according to the heat balance principle, calculate the difference between the temperature of the first single battery after each adjustment and the average temperature until the difference between the temperature of the first single battery and the average temperature reaches the preset convergence condition, and then determine the area of the target heat dissipation window of the first single battery;

[0049] Specifically, based on the temperature and average temperature of the first single cell, it can be determined whether it is necessary to increase or decrease the area of the initial heat dissipation window of the first single cell. Using the step-by-step analysis method, the area of the heat dissipation window of the first single cell is adjusted step by step. After each adjustment of the area of the heat dissipation window of the first single cell, according to the principle of heat balance, the difference between the temperature of the first single cell after each adjustment and the average temperature is calculated. When the difference between the temperature of the first single cell and the average temperature meets the convergence condition, the area of the heat dissipation window of the first single cell that meets this convergence condition is selected as the target heat dissipation window area. Among them, the number of times of adjusting the area of the heat dissipation window of the first single cell step by step is at least two, and the convergence condition can be a numerical range, such as 0 to 5 °C. That is, when the difference between the temperature of the first single cell after several adjustments and the average temperature is within 0 to 5 °C, the area of the heat dissipation window of the first single cell under this adjustment is selected as the target heat dissipation window area of the first single cell. Or, in another embodiment, the convergence condition is: after a limited number of adjustments to the initial heat dissipation window of the first single cell, the area of the heat dissipation window when the difference between the temperature of the first single cell and the average temperature is the smallest is used as the target heat dissipation window area of the first single cell.

[0050] Further, using the step-by-step analysis method to gradually adjust the area of the heat dissipation window of the first single cell can be specifically: set the minimum unit of change in the heat dissipation window area as the step size, and use 1 such step size as the change amount to gradually adjust the initial heat dissipation window area of the first single cell. That is, each adjustment amount of the initial heat dissipation window area of the first single cell is one step size. Exemplarily, for the first adjustment: the change amount of the area of the initial heat dissipation window of the first single cell is one step size; for the second adjustment, the change amount of the area of the initial heat dissipation window of the first single cell is 2 step sizes; for the third adjustment, the change amount of the area of the initial heat dissipation window of the first single cell is 3 step sizes, and so on. For the a-th adjustment, the change amount of the area of the initial heat dissipation window of the first single cell is a step sizes. Where a is a positive integer greater than or equal to 4.

[0051] Repeat the above steps until the differences between the temperatures of the second single cell to the n-th single cell and the average temperature all reach the preset convergence condition, and then determine the target heat dissipation window areas of the second single cell to the n-th single cell. Regarding the specific steps for determining the target heat dissipation window areas of the second single cell to the n-th single cell, reference can be made to the above steps for determining the target heat dissipation window area of the first single cell, and this embodiment will not elaborate on this.

[0052] Next, the embodiments of the present application will elaborate on "calculating the difference between the temperature of the first single cell after each adjustment and the average temperature according to the principle of heat balance".

[0053] The heat balance principle is that the heat dissipation of the single cell = the interfacial heat exchange = the heat absorption of the liquid cooling plate. Among them, the heat dissipation of the single cell = ΔT1C1 + Q; ΔT1 is the temperature change of the single cell, C1 is the heat capacity of the single cell, and Q is the heat generation of the single cell; the interfacial heat flux = ΔT2(S1K1 + S2K2); ΔT2 is the temperature difference between the single cell and the liquid cooling plate, S1 is the contact area between the insulating film and the liquid cooling plate, K1 is the heat conduction coefficient between the insulating film and the liquid cooling plate, S2 is the area of the heat dissipation window, and K2 is the heat conduction coefficient between the housing and the liquid cooling plate, where S1 + S2 is the contact area S between the single cell and the liquid cooling plate; the heat absorption of the liquid cooling plate = ΔT3C2L; C2 is the specific heat capacity of the coolant in the liquid cooling plate, and L is the mass flow rate of the coolant. ΔT2, C1, Q, S, K1, and K2 above can all be obtained from the battery module model and the initial simulation results, which will not be elaborated in the embodiments of the present application.

[0054] Specifically, according to the interfacial heat flux = ΔT2(S1K1 + S2K2), after adjusting the area S2 of the initial heat dissipation window of the first battery, through S1 + S2 = S, the area of S1 can be calculated. On the premise of knowing ΔT2, S1, K1, S2, and K2, the value of the interfacial heat flux between the first single cell and the liquid cooling plate can be calculated. Since the heat dissipation of the first single cell is equal to the interfacial heat exchange between the first single cell and the liquid cooling plate, according to the heat dissipation of the single cell = ΔT1C1 + Q, we get The temperature change of the first single cell can be calculated. Then, combined with the temperature of the first single cell under normal conditions, the difference between the temperature of the first single cell after each adjustment and the average temperature can be calculated. When this difference reaches the above preset convergence condition, the area of the target heat dissipation window of the first single cell can be determined.

[0055] After determining the area of the target heat dissipation window of the first single cell, the above steps can be repeated to determine the areas of the target heat dissipation windows of the second single cell to the nth single cell. However, it should be understood that since the temperature of the coolant will rise slightly after cooling the first single cell, at this time, according to the heat absorption of the liquid cooling plate = ΔT3C2L, that is, Calculate the temperature of the coolant flowing through the second single cell. Among them, the heat absorption of the liquid cooling plate is equal to the interfacial heat flux of the above first single cell, and C2 and L are both known parameters. Therefore, the temperature of the coolant flowing through the second single cell can be calculated through the above formula, so that the size of the target heat dissipation window of the second single cell can be determined according to the heat balance principle. In summary, the embodiments of the present application can determine the sizes of the target heat dissipation windows of the first single cell to the nth single cell according to the heat balance principle.

[0056] In another embodiment, determining the area of the target heat dissipation window for each single battery according to the temperature and average temperature of each single battery includes:

[0057] When the temperatures of the first single battery to the nth single battery are all equal to the average temperature, according to the difference between the temperature of each single battery and the average temperature and the heat balance principle, calculate the area of the target heat dissipation window of the first single battery to the area of the target heat dissipation window of the nth single battery in sequence; according to the calculation results, determine the area of the target heat dissipation window of the first single battery to the nth single battery. Taking the first single battery as an example, when the temperature of the first single battery changes to the average temperature, calculate the difference between the temperature of the first single battery and the average temperature, denoted as ΔT4. According to the formula of the heat dissipation of the single battery = ΔT1C1 + Q, calculate the heat dissipation of the first single battery when changing ΔT4. Then, according to the fact that the heat dissipation of the first single battery is equal to the interfacial heat flux of the first single battery, and the interfacial heat flux = ΔT2(S1K1 + S2K2), S1 + S2 = S, that is, Calculate the area of the target heat dissipation window of the first single battery when it is at the average temperature, so as to determine the area of the target heat dissipation window of the first single battery. Furthermore, by repeating the above steps, the areas of the target heat dissipation windows of the remaining single batteries can be obtained.

[0058] Similarly, since the temperature of the coolant will rise slightly after cooling the first single battery, at this time, according to the heat absorption of the liquid cooling plate = ΔT3C2L, that is, The temperature of the coolant when flowing through each single battery can be calculated.

[0059] It should be noted that the formula of the heat balance principle in the above embodiment is only a calculation formula provided by this application and is not used to limit this application. In fact, the heat balance principle also includes more other formulas. Those skilled in the art can consult relevant reference books to improve or supplement the calculation formula provided by this application, and it should all be covered within the protection scope of this application.

[0060] Reference Figures 2 to 8 , this application embodiment provides a battery module, which includes a battery pack and a liquid cooling plate 20. The battery pack includes a plurality of single batteries 10. Each single battery 10 includes a housing 13 and an insulating film 11. The insulating film 11 is coated on the outer surface of the housing 13. The insulating film 11 is provided with a heat dissipation window 12 penetrating along the thickness direction of the insulating film 11. The liquid cooling plate 20 is attached to the outer surface of the insulating film 11 and covers the heat dissipation window 12. The heat dissipation window 12 in this embodiment can be the target heat dissipation window in any of the above method embodiments.

[0061] Specifically, the single cell 10 further includes a thermal conductive adhesive layer 14, the thermal conductive adhesive layer 14 is bonded at the heat dissipation window 12, and the liquid cooling plate 20 is attached to the heat dissipation window 12 through the thermal conductive adhesive layer 14.

[0062] As described above, the heat exchange area between the single cell 10 and the liquid cooling plate 20 is S. Specifically, this heat exchange area is divided into two parts. The first part is the heat exchange area S1 between the single cell 10 and the liquid cooling plate 20 through the heat dissipation window 12 of the insulating film 11, and S1 is the area of the above-mentioned target heat dissipation window. The second part is the heat exchange area S2 between the single cell 10 and the liquid cooling plate 20 through the heat dissipation window 12. Therefore, in one embodiment, in addition to being disposed at the heat dissipation window 12, the thermal conductive adhesive layer 14 can also be disposed between the insulating film 11 and the liquid cooling plate 20. In this way, while connecting the insulating film 11 and the liquid cooling plate 20, the heat exchange capacity between the insulating film 11 and the liquid cooling plate 20 can be maximized.

[0063] In some embodiments, the heat dissipation window 12 can be disposed on the side surface of the insulating film 11 or on the bottom surface of the insulating film 11. Refer to Figure 3 and in combination with Figure 2 , Figure 2 the specific opening position of the heat dissipation window 12 of the single cell 10 shown is not shown. Figure 3 In the described embodiment, the heat dissipation window 12 is located on the bottom surface of the single cell 10. In another embodiment, refer to Figure 4 and in combination with Figure 2 , in Figure 4 the shown embodiment, the heat dissipation window 12 is located on the side surface of the single cell 10. In yet another embodiment, multiple heat dissipation windows 12 can be provided (not shown). One of the multiple heat dissipation windows 12 is located on the bottom surface of the single cell 10, and one is located on the side surface of the single cell 10 to increase the heat exchange area between the housing 13 and the liquid cooling plate 20 and improve the heat exchange efficiency.

[0064] In one embodiment, refer to Figure 5 , in addition to being disposed at the heat dissipation window 12, the thermal conductive adhesive layer 14 can also be disposed between the insulating film 11 and the liquid cooling plate 20. In this way, while connecting the insulating film 11 and the liquid cooling plate 20, the heat exchange capacity between the insulating film 11 and the liquid cooling plate 20 can be maximized. In a specific embodiment, the single cell 10 further includes a first heat exchange surface for attaching to the liquid cooling plate 20. The first heat exchange surface includes a housing heat exchange surface located at the heat dissipation window 12 and an insulating film heat exchange surface that fits with the liquid cooling plate 20. The structural adhesive layer 14 is attached to the housing heat exchange surface and the insulating film heat exchange surface at the heat dissipation window 12 to maximize the heat exchange capacity between the single cell 10 and the liquid cooling plate 20.

[0065] In one embodiment, the thickness of the thermal conductive adhesive layer 14 is greater than or equal to 1.5 mm and less than a first preset thickness. It can be understood that setting the thickness of the thermal conductive adhesive layer 14 to be greater than or equal to 1.5 mm can ensure insulation between the housing 13 and the liquid cooling plate 20 and avoid short - circuit faults.

[0066] Among them, the first preset thickness can be specifically set according to other factors such as the area of the heat dissipation window 12, and it can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc., but is not limited thereto.

[0067] In one embodiment, the heat dissipation window 12 is a symmetric structure. For example, the heat dissipation window 12 can be circular, rectangular, rhombic, equilateral triangular, regular polygon (number of sides greater than 4), etc. By setting the heat dissipation window 12 as a symmetric figure, it is convenient for operators to open the heat dissipation window 12 on the insulating film 11 and improve the opening efficiency. As Figure 2 In the illustrated embodiment, the shape of the heat dissipation window 12 is rectangular.

[0068] Furthermore, the shape of the heat dissipation window 12 can be set to be the same as the shape of the liquid cooling plate 20.

[0069] In one embodiment, the area of the heat dissipation window 12 is less than or equal to the contact area between the single - cell battery 10 and the liquid cooling plate 20. Among them, the contact area refers to the surface area where the single - cell battery 10 and the liquid cooling plate 20 are in contact with each other. Since the heat dissipation window 12 is designed for heat dissipation, the area of the heat dissipation window 12 should be less than or equal to the contact area between the single - cell battery 10 and the liquid cooling plate 20.

[0070] In one embodiment, the insulating film 11 further has a safety edge 111 on the side with the heat dissipation window 12, and the safety edge 111 is arranged around the heat dissipation window 12. The safety edge 111 arranged around the heat dissipation window 12 can effectively protect the area around the heat dissipation window 12 of the single - cell battery 10 from external damage or contact, and further improve the safety of the battery pack. It should be noted that when the insulating film 11 wraps the housing 13, an insulating film fold 15 will be formed. The specific direction of the insulating film fold 15 is related to the wrapping process of the insulating film 11, and this embodiment does not make specific limitations on this. In another embodiment, the insulating film 11 can also be coated on the outer surface of the housing 13 by spraying or other forms. At this time, no insulating film fold 15 will be formed.

[0071] In one embodiment, the single - cell battery 10 further includes a structural adhesive layer, and the structural adhesive layer is bonded to the outer surface of the insulating film 11 for fixing the single - cell battery 10.

[0072] Reference Figure 6As shown, a plurality of the single cell batteries 10 include a first single cell battery to an nth single cell battery, and the first single cell battery to the nth single cell battery are configured to be sequentially distributed along the flow direction of the coolant in the liquid cooling plate 20; along the flow direction of the coolant, the area of the heat dissipation window of the first single cell battery to the area of the heat dissipation window of the nth single cell battery gradually increases; to balance the influence brought by the gradually rising coolant. Wherein, n is a positive integer greater than or equal to 2.

[0073] As Figure 7 In the embodiment shown, there are 3 battery packs, and each battery pack includes a plurality of single cell batteries 10 arranged in parallel. Each single cell battery 10 is provided with at least two heat dissipation windows 12, one heat dissipation window 12 is located on the bottom surface of the single cell battery 10, and the surface size of the heat dissipation window 12 on the bottom surface is 80% of the length and width of the housing 13, that is, the length of the heat dissipation window 12 is 0.8 times the length of the bottom surface of the housing 13, and the width is 0.8 times the width of the bottom surface of the housing 13. The other heat dissipation window 12 is located on the side surface of the battery pack, and the width of the heat dissipation window 12 on the side surface is 0.8 times the width of the side surface of the housing 13, and the height is 0.7 times the height of the side surface of the housing 13. A plurality of liquid cooling plates 20 are provided, and the plurality of liquid cooling plates 20 at least include a first liquid cooling plate 21 and a second liquid cooling plate 22. The first liquid cooling plate 21 is attached to the heat dissipation window 12 on the side surface of the battery pack, and the second liquid cooling plate 22 is attached to the heat dissipation window 12 on the bottom surface of the battery pack. This embodiment can correspond to a battery module with a fast charging function. In another embodiment, refer to Figure 8 As shown, there can be 6 battery packs, and each single cell battery 10 is provided with at least one heat dissipation window 12, and the heat dissipation window 12 can be located on the side surface of the single cell battery 10 and face the first liquid cooling plate 21.

[0074] The embodiment of the present application further provides a vehicle, including the battery module described in any one of the above embodiments.

[0075] The foregoing is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of protection of the present application.

Claims

1. A design method for a battery module, characterized in that, Including: Establish a battery module model, where the battery module model includes a battery pack and a liquid cooling plate. The battery pack includes a plurality of single cells, and each single cell includes a housing and an insulating film. The insulating film is coated on the outer surface of the housing, and the insulating film is provided with an initial heat dissipation window penetrating along the thickness direction of the insulating film. The liquid cooling plate is attached to the outer surface of the insulating film and covers the initial heat dissipation window; According to the operating conditions of the battery module model, perform a thermal simulation process on the battery module model to obtain an initial simulation result; According to the initial simulation result, determine the area of the target heat dissipation window of each single cell.

2. The method according to claim 1, characterized in that, The initial simulation result at least includes the temperature of each single cell and the average temperature of the plurality of single cells; The determining the area of the target heat dissipation window of each single cell according to the initial simulation result includes: Determine the area of the target heat dissipation window of each single cell according to the temperature of each single cell and the average temperature.

3. The method according to claim 2, characterized in that, The plurality of single cells include a first single cell to an nth single cell, and the first single cell to the nth single cell are configured to be distributed in sequence along the flow direction of the coolant in the liquid cooling plate, where n is greater than or equal to 2; The determining the area of the target heat dissipation window of each single cell according to the temperature of each single cell and the average temperature further includes: According to the temperature of the first single cell and the average temperature, gradually adjust the area of the initial heat dissipation window of the first single cell. According to the principle of heat balance, calculate the difference between the temperature of the first single cell after each adjustment and the average temperature until the difference between the temperature of the first single cell and the average temperature reaches a preset convergence condition, and then determine the area of the target heat dissipation window of the first single cell; Repeat the above steps until the differences between the temperatures of the second single cell to the nth single cell and the average temperature all reach the preset convergence condition, and then determine the areas of the target heat dissipation windows of the second single cell to the nth single cell.

4. The method according to claim 3, wherein According to the temperature of the first single cell and the average temperature, gradually adjusting the area of the initial heat dissipation window of the first single cell includes: Set the minimum unit of change in the heat dissipation window area as the step size, and gradually adjust the area of the initial heat dissipation window of the first single cell with 1 step size as the change amount.

5. The method according to claim 2, wherein The plurality of single cells include a first single cell to an nth single cell, and the first single cell to the nth single cell are configured to be distributed in sequence along the flow direction of the coolant in the liquid cooling plate, where n is greater than or equal to 2; The determining the area of the target heat dissipation window of each single cell according to the initial simulation result further includes: When the temperatures of the first single cell to the nth single cell are all equal to the average temperature, according to the difference between the temperature of each single cell and the average temperature and the heat balance principle, the areas of the target heat dissipation windows of the first single cell to the nth single cell are calculated in sequence; according to the calculation results, the areas of the target heat dissipation windows of the first single cell to the nth single cell are determined.

6. The method according to any one of claims 3 to 5, characterized in that The heat balance principle is: the heat dissipation of the single cell = the interfacial heat exchange = the heat absorption of the liquid cooling plate; The heat dissipation of the single cell = ΔT1C1 + Q; ΔT1 is the temperature change of the single cell, C is the heat capacity of the single cell, and Q is the heat generation of the single cell; The interfacial heat flow = ΔT2(S1K1 + S2K2); ΔT2 is the temperature difference between the single cell and the liquid cooling plate, S1 is the contact area between the insulating film and the liquid cooling plate, K1 is the heat conduction coefficient between the insulating film and the liquid cooling plate, S2 is the area of the heat dissipation window, K2 is the heat conduction coefficient between the housing and the liquid cooling plate, where S1 + S2 is equal to the contact area S between the single cell and the liquid cooling plate; The heat absorption of the liquid cooling plate = ΔT3C2L; C2 is the specific heat capacity of the coolant in the liquid cooling plate, and L is the mass flow rate of the coolant.

7. A battery module designed by the method according to any one of claims 1 to 6, characterized in that, It includes a battery pack and a liquid cooling plate. The battery pack includes a plurality of single cells. Each single cell includes a housing and an insulating film. The insulating film covers the outer surface of the housing. The insulating film is provided with a heat dissipation window penetrating along the thickness direction of the insulating film. The liquid cooling plate is attached to the outer surface of the insulating film and covers the heat dissipation window.

8. The battery module according to claim 7, wherein The plurality of single cells include the first single cell to the nth single cell, and the first single cell to the nth single cell are configured to be distributed in sequence along the flow direction of the coolant in the liquid cooling plate; in the direction of the coolant flow, the areas of the heat dissipation windows of the first single cell to the nth single cell gradually increase.

9. The battery module according to claim 7, characterized in that, The heat exchange amount of each single cell and the liquid cooling plate is equal.

10. A vehicle, characterized in that, It includes the battery module according to any one of claims 7 to 9.

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