Power battery temperature difference optimization structure

Abstract

The application relates to a power battery temperature difference optimization structure, which belongs to the field of power battery thermal management and is used for reducing the temperature difference of battery cells at different positions in a battery module. The power battery temperature difference optimization structure comprises a battery mounting shell, a liquid cooling plate, a battery module, an elastic heat insulation material layer and a heat conduction adhesive layer. A containing cavity is formed in the battery mounting shell, and two openings are arranged at the bottom of the side wall of the battery mounting shell. The liquid cooling plate is arranged on the bottom wall of the containing cavity of the battery mounting shell, and the liquid cooling plate is provided with a liquid cooling inlet and a liquid cooling outlet. The liquid cooling inlet and the liquid cooling outlet are respectively and correspondingly communicated with the two openings on the battery mounting shell. The battery module is arranged in the containing cavity of the battery mounting shell and is arranged on the liquid cooling plate. The battery cell of the battery module abuts against the liquid cooling plate. The elastic heat insulation material layer is arranged at the liquid cooling inlet of the liquid cooling plate, the elastic heat insulation material layer is arranged in the battery mounting shell, and the elastic heat insulation material layer is arranged between the liquid cooling plate and the battery module.

Description

Technical Field

[0001] This application relates to the field of power battery thermal management, and in particular to a power battery temperature difference optimization structure. Background Technology

[0002] With the rapid development of new energy vehicles, the issue of temperature uniformity in power batteries is becoming increasingly prominent. During charging and discharging, existing battery modules exhibit uneven heat distribution due to the thermal management design of the battery module and the inherent characteristics of the battery itself, resulting in significant temperature differences between the cells at the inlet and outlet of the battery module. This temperature difference accelerates battery aging and reduces overall cycle life. Utility Model Content

[0003] This application provides a power battery temperature difference optimization structure to reduce the temperature difference between cells at different locations within the battery module.

[0004] This application provides a power battery temperature difference optimization structure, including a battery mounting shell, a liquid cooling plate, a battery module, an elastic heat insulation material layer, and a thermally conductive adhesive layer. A receiving cavity is formed within the battery mounting shell, and two openings are spaced apart at the bottom of one sidewall of the battery mounting shell. The liquid cooling plate is disposed on the bottom wall of the receiving cavity of the battery mounting shell, and the liquid cooling plate has a liquid cooling inlet and a liquid cooling outlet, which are respectively connected to the two openings located on the battery mounting shell. The battery module is disposed within the receiving cavity of the battery mounting shell and on the liquid cooling plate, with the battery cells of the battery module abutting against the liquid cooling plate. The elastic heat insulation material layer is disposed at the liquid cooling inlet of the liquid cooling plate, located inside the battery mounting shell, and between the liquid cooling plate and the battery module. The thermally conductive adhesive layer is disposed outside the elastic heat insulation material layer and fills the space between the liquid cooling plate and the battery module.

[0005] In this application, the liquid cooling plate directly contacts the battery cell and removes heat through the circulation of coolant to achieve active heat dissipation. The elastic thermal insulation material layer at the liquid cooling inlet blocks the direct impact of the low-temperature coolant on the battery cell, avoiding local overcooling. The thermally conductive adhesive layer fills the non-insulated area, enhancing the heat transfer efficiency between the battery cell and the liquid cooling plate, ensuring uniform heat dissipation, and reducing the temperature difference between the battery cells.

[0006] By using an elastic thermal insulation layer at the liquid cooling inlet to block the direct impact of the low-temperature coolant on the battery cells and avoid localized overcooling, the temperature difference between different areas of the battery cells within the battery module can be reduced, resulting in a more uniform temperature within the power battery and improved battery consistency. When the battery pack needs to be heated by a liquid cooling plate, the elastic thermal insulation layer at the inlet can reduce the loss of heat from the heating fluid to the low-temperature environment, allowing the heat to be more concentrated on the battery cells and increasing the heating rate. This can also reduce the temperature difference between different areas of the battery cells within the battery module.

[0007] In some embodiments of this application, the elastic thermal insulation material layer is thermal insulation foam. The porous structure inside the thermal insulation foam can effectively block heat conduction and reduce the transfer of low temperature from the liquid cooling inlet to the battery cell; the elasticity of the foam can compensate for installation gaps, ensuring a tight fit with the liquid cooling plate and battery cell, and avoiding thermal insulation failure due to vibration or deformation; the foam material is low in cost and easy to process.

[0008] In some embodiments of this application, the thickness of the insulating foam is 0.5mm to 1.5mm. This thickness range can avoid the weakening of the insulation effect caused by excessive thickness, and can also avoid the increase in the distance between the liquid cooling plate and the battery cell caused by excessive thickness, which would affect the thermal conductivity of the non-insulated area.

[0009] In some embodiments of this application, the battery module includes multiple battery cells, and an elastic thermal insulation material layer is disposed between the battery cells near the liquid cooling inlet and the liquid cooling plate. The coolant temperature is lowest at the liquid cooling inlet, and direct contact with the battery cells can easily cause the temperature of the battery cells in this area to be lower than that of other battery cells, creating a temperature difference. The thermal insulation foam blocks the conduction of low temperature, making the temperature of the battery cells at the inlet more consistent with that of other areas, thus avoiding battery performance degradation due to localized overcooling.

[0010] In some embodiments of this application, the size of the elastic thermal insulation material layer along the direction perpendicular to the liquid cooling inlet is 40% to 50% of the cell size. The low-temperature influence range of the coolant at the liquid cooling inlet is usually limited to 1 to 2 nearby cells. A width ratio of 40% to 50% can accurately cover this area, avoiding an excessively large thermal insulation range that would affect the heat dissipation of other cells, and avoiding an excessively small range that would not meet the thermal insulation requirements.

[0011] In some embodiments of this application, the thermal conductivity of the elastic insulation material layer is ≤0.08 W / (m·K). Materials within this range are mostly low thermal conductivity materials, which can effectively suppress heat conduction and ensure that the low temperature at the liquid cooling inlet does not significantly affect the cell temperature. Attached Figure Description

[0012] The accompanying drawings are provided to further illustrate the technical solution of this utility model and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solution of this utility model and do not constitute a limitation on the technical solution of this utility model.

[0013] Figure 1 This is a schematic diagram of the battery mounting shell and liquid cooling plate in a power battery temperature difference optimization structure provided in an embodiment of this application.

[0014] Figure 2 This is a schematic diagram showing the installation position of the elastic thermal insulation material layer in a power battery temperature difference optimization structure provided in this application embodiment.

[0015] Reference numerals: 1-Battery mounting shell; 11-Receiving cavity; 12-Opening; 2-Liquid cooling plate; 21-Liquid cooling inlet; 22-Liquid cooling outlet; 3-Battery module; 4-Elastic thermal insulation material layer; 5-Thermal conductive adhesive layer. Detailed Implementation

[0016] 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.

[0017] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0018] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, when describing pipelines, the terms "connected" and "linked" as used in this application have the meaning of establishing electrical connection. The specific meaning needs to be understood in conjunction with the context.

[0020] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0021] With the rapid development of new energy vehicles, the issue of temperature uniformity in power batteries is becoming increasingly prominent. During charging and discharging, existing battery modules exhibit uneven heat distribution due to the thermal management design of the battery module and the inherent characteristics of the battery itself, resulting in significant temperature differences between the cells at the inlet and outlet of the battery module. This temperature difference accelerates battery aging and reduces overall cycle life.

[0022] Therefore, please refer to Figure 1 and Figure 2 This application provides a power battery temperature difference optimization structure, including a battery mounting shell 1, a liquid cooling plate 2, a battery module 3, an elastic heat insulation material layer 4, and a thermally conductive adhesive layer 5.

[0023] Please refer to Figure 1 The battery mounting shell 1 has a cavity 11 inside, and two openings 12 are provided at intervals on the bottom of one side wall of the battery mounting shell 1. The battery mounting shell 1 is the external protective shell of the power battery. Its main functions are to support the internal components, isolate the external environment (such as waterproofing and dustproofing), and withstand mechanical loads. The cavity 11 is the space inside the battery mounting shell 1, which is used to install core components such as the battery module 3 and the liquid cooling plate 2, ensuring that the layout of each component is compact and orderly.

[0024] Please refer to Figure 1 Two through holes at the bottom of the side wall are used to connect the inlet and outlet pipes of the liquid cooling system to achieve the circulation of coolant. The battery pack housing can be made of aluminum alloy, with a rectangular receiving cavity 11 inside. Two threaded interfaces can be set on the bottom side wall as liquid cooling inlets and outlets to connect with the vehicle's liquid cooling pipeline.

[0025] Please refer to Figure 1 The liquid cooling plate 2 is disposed on the bottom wall of the receiving cavity 11 of the battery mounting shell 1. The liquid cooling plate 2 has a liquid cooling inlet 21 and a liquid cooling outlet 22, which are respectively connected to two openings 12 located on the battery mounting shell 1.

[0026] Please refer to Figure 1 The liquid cooling plate 2 is a metal plate with internal flow channels. Its material can be aluminum alloy or copper. The coolant in the flow channels absorbs the heat of the battery module 3. The inlet of the liquid cooling plate 2 is connected to the inlet pipe of the shell opening 12, and the outlet is connected to the outlet pipe, forming a closed cooling circulation loop.

[0027] Please refer to Figure 1 The flow channels within the liquid cooling plate 2 can be U-shaped, arc-shaped, or serpentine. The assembly method between the liquid cooling plate 2 and the battery pack housing adopts existing conventional methods.

[0028] The battery module 3 is housed within the receiving cavity 11 of the battery mounting housing 1 and is mounted on the liquid cooling plate 2. The battery cells of the battery module 3 are in contact with the liquid cooling plate 2. The battery module 3 is a unit composed of multiple cells connected in series and parallel, and is the core of the energy storage of the battery pack. It is fixed in the receiving cavity 11 by a bracket. The bottom of the battery cell directly contacts the surface of the liquid cooling plate 2, transferring heat to the liquid cooling plate 2 through thermal conduction to achieve heat dissipation.

[0029] Please refer to Figure 2 An elastic thermal insulation layer 4 is disposed at the liquid cooling inlet 21 of the liquid cooling plate 2. The elastic thermal insulation layer 4 is located inside the battery mounting shell 1 and between the liquid cooling plate 2 and the battery module 3. The elastic thermal insulation layer 4 can be thermal insulation foam, such as EVA foam, PU foam, or MPP foam. This type of material has elasticity and low thermal conductivity and can be disposed between the liquid cooling plate 2 and the battery cell near the liquid cooling inlet 21.

[0030] Please refer to Figure 2 The elastic thermal insulation material layer 4 can be made of closed-cell foam material, such as MPP foam, which has low compression performance. The elastic thermal insulation material layer 4 can be pre-compressed and bonded to the battery module 3 and the liquid cooling plate 2 by means of adhesive fixation. When the liquid cooling inlet 21 of the liquid cooling plate 2 needs to be sealed, a clearance area can be formed on the elastic thermal insulation material to facilitate the installation and configuration of the seal.

[0031] Please refer to Figure 2 The thermally conductive adhesive layer 5 is disposed on the outside of the elastic thermal insulation material layer 4, and fills the space between the liquid cooling plate 2 and the battery module 3. The thermally conductive adhesive layer 5 can be a thermally conductive structural adhesive, such as silicone thermally conductive adhesive, polyurethane thermally conductive adhesive, epoxy thermally conductive adhesive, or other types of thermally conductive structural adhesive. The thermally conductive adhesive layer 5 can enhance heat conduction in non-insulated areas (outside the thermal insulation foam), ensuring that all cell areas except the inlet are in close contact with the liquid cooling plate 2.

[0032] Please refer to Figure 1 and Figure 2 In this application, the liquid cooling plate 2 directly contacts the battery cell and removes heat through the circulation of coolant to achieve active heat dissipation. The elastic heat insulation material layer 4 blocks the direct impact of the low-temperature coolant on the battery cell at the liquid cooling inlet 21, avoiding local overcooling. The thermally conductive adhesive layer 5 fills the non-insulated area, enhances the heat conduction efficiency between the battery cell and the liquid cooling plate 2, ensures uniform heat dissipation, and reduces the temperature difference between the battery cells.

[0033] By using the elastic heat insulation material layer 4 at the liquid cooling inlet 21 to block the direct impact of the low-temperature coolant on the battery cell and avoid local overcooling, the temperature difference between the battery cells in different areas of the battery module 3 can be reduced, thereby making the temperature inside the power battery more uniform and improving battery consistency. When the battery pack needs to be heated by the liquid cooling plate 2, the elastic heat insulation material layer 4 at the inlet can reduce the heat loss of the heating liquid to the low-temperature environment, making the heat more concentrated on the battery cell and increasing the heating rate. This can also reduce the temperature difference between the battery cells in different areas of the battery module 3.

[0034] In some examples, the elastic insulation layer 4 is insulation foam. The porous structure inside the insulation foam can effectively block heat conduction and reduce the transfer of low temperature from the liquid cooling inlet 21 to the battery cell; the elasticity of the foam can compensate for the installation gap, ensuring a tight fit with the liquid cooling plate 2 and the battery cell, and avoiding insulation failure due to vibration or deformation; the foam material is low in cost and easy to process.

[0035] In other examples, the elastic insulation layer 4 can also be aerogel felt or silica ceramic fiber, which can also provide a certain degree of insulation.

[0036] In some examples, the thickness of the insulating foam is 0.5mm to 1.5mm. This thickness range avoids the weakening of the insulation effect caused by excessively thin foam, and also avoids the increase in the distance between the liquid cooling plate 2 and the battery cell caused by excessively thick foam, which would affect the thermal conductivity of the non-insulated areas.

[0037] For example, the thickness of the thermal insulation foam can be 0.5mm, 1mm, 1.2mm or 1.5mm.

[0038] In other examples, for areas with high heating and heat dissipation requirements, the temperature difference between the liquid inside the liquid cooling plate 2 and the battery pack is large. In this case, a thicker layer can be set, such as 2mm or 2.5mm. At the same time, a certain recessed area can be set on the liquid cooling plate 2 to facilitate the installation of the heat insulation layer.

[0039] In some examples, the battery module 3 includes multiple battery cells, and an elastic thermal insulation layer 4 is disposed between the battery cells near the liquid cooling inlet 21 and the liquid cooling plate 2. The coolant temperature is lowest at the liquid cooling inlet 21. Direct contact with the battery cells can easily cause the temperature of the cells in this area to be lower than that of other cells, creating a temperature difference. The thermal insulation foam blocks the conduction of low temperature, making the temperature of the cells at the inlet more consistent with that of other areas, thus avoiding battery performance degradation due to localized overcooling.

[0040] In some examples, in the power battery liquid cooling system, when the coolant flows from the liquid cooling inlet 21 into the liquid cooling plate 2, the coolant temperature at the inlet is usually lower than that at the outlet. If the battery cell near the liquid cooling inlet 21 is in direct contact with the low-temperature liquid cooling plate 2, the temperature of the battery cell in that area may be too low, resulting in a significant temperature difference with other battery cells, which affects the temperature uniformity and overall performance of the battery module 3.

[0041] By using the elastic thermal insulation material layer 4 to block the direct heat conduction between the low-temperature liquid cooling plate 2 and the battery cell, the heat dissipation rate in this area is reduced, making the temperature of the battery cell near the inlet closer to that of other battery cells in the module, thus avoiding excessive temperature difference.

[0042] The flexibility of the elastic thermal insulation material layer 4 can also buffer the compressive stress between the battery cell and the liquid cooling plate 2, preventing the battery cell casing from being damaged due to long-term stress and improving structural reliability.

[0043] In some examples, the size of the elastic thermal insulation layer 4 is 40% to 50% of the cell size along the direction perpendicular to the liquid cooling inlet. The low-temperature influence range of the coolant at the liquid cooling inlet 21 is usually limited to 1 to 2 nearby cells. A width ratio of 40% to 50% can accurately cover this area, avoiding an excessively large thermal insulation range that would affect the heat dissipation of other cells, and avoiding an excessively small range that would not meet the thermal insulation requirements.

[0044] For example, along the direction perpendicular to the liquid cooling inlet, the size of the elastic thermal insulation material layer 4 can be 40%, 45%, or 50% of the cell. Here, the size of the elastic thermal insulation material layer 4 can be the width, while the length of the elastic thermal insulation material layer 4 can be designed as needed to form a rectangle, trapezoid, or semicircle.

[0045] In some examples, the thermal conductivity of the elastic insulation layer 4 is ≤0.08W / (m·K). Materials within this range are mostly low thermal conductivity materials, which can effectively suppress heat conduction and ensure that the low temperature at the liquid cooling inlet 21 does not significantly affect the cell temperature.

[0046] For example, thermal conductivity is a parameter that measures the heat transfer capacity of a material. This requirement can enable materials that meet the requirements to have better thermal insulation performance. The selection of the elastic thermal insulation material layer 4 has been explained above and will not be repeated here.

[0047] In some examples, when the battery requests a heating signal, the vehicle's thermal management system introduces hot water. When the inlet is filled with insulating foam, the heat transfer at the inlet is reduced, and the Tmax at the inlet decreases, thus achieving the temperature difference between Tmax and Tmin.

[0048] When the battery requests a cooling signal, the vehicle's thermal management system introduces cold water. When the inlet is filled with insulating foam, the heat transfer at the inlet is reduced, and the temperature Tmin at the inlet increases, thus achieving the temperature difference between Tmax and Tmin.

[0049] The structure provided by this solution can reduce the temperature difference between Tmax and Tmin, thereby improving the temperature consistency of the battery.

[0050] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0051] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power battery temperature difference optimization structure, characterized in that, include: A battery mounting housing having a receiving cavity inside, and two openings spaced apart at the bottom of one side wall of the battery mounting housing; A liquid cooling plate is disposed on the bottom wall of the receiving cavity of the battery mounting housing. The liquid cooling plate has a liquid cooling inlet and a liquid cooling outlet, and the liquid cooling inlet and the liquid cooling outlet are respectively connected to two openings located on the battery mounting housing. A battery module is disposed within the receiving cavity of the battery mounting shell, the battery module is disposed on the liquid cooling plate, and the battery cells of the battery module abut against the liquid cooling plate; An elastic thermal insulation material layer is disposed at the liquid cooling inlet of the liquid cooling plate, the elastic thermal insulation material layer is located inside the battery mounting shell, and the elastic thermal insulation material layer is located between the liquid cooling plate and the battery module; A thermally conductive adhesive layer is disposed on the outside of the elastic thermal insulation material layer, and the thermally conductive adhesive layer fills the space between the liquid cooling plate and the battery module.

2. The power battery temperature difference optimization structure according to claim 1, characterized in that, The elastic thermal insulation material layer is thermal insulation foam.

3. The power battery temperature difference optimization structure according to claim 2, characterized in that, The thickness of the thermal insulation foam is 0.5mm to 1.5mm.

4. The power battery temperature difference optimization structure according to any one of claims 1 to 3, characterized in that, The battery module includes multiple battery cells, and the elastic heat insulation material layer is disposed between the battery cell and the liquid cooling plate near the liquid cooling inlet.

5. The power battery temperature difference optimization structure according to claim 4, characterized in that, Along the direction perpendicular to the liquid cooling inlet, the size of the elastic thermal insulation material layer is 40% to 50% of the cell.

6. The power battery temperature difference optimization structure according to claim 1, characterized in that, The thermal conductivity of the elastic insulation material layer is ≤0.08W / (m·K).

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