Lower box device and battery box

Abstract

The application provides a lower box device and a battery box, and relates to the technical field of power batteries. The lower box device comprises: a box main body having a containing cavity configured to contain a plurality of power batteries; and a cooling structure, at least a part of which is arranged in the containing cavity, and the cooling structure is arranged between two adjacent power batteries and / or between the power battery and the box main body, so as to cool the large surface of the power battery. The box main body contains the power battery, the cooling structure is arranged in the containing cavity of the box structure, and the cooling structure can contact the large surface of the power battery, so that the power battery can be cooled, the contact area of the power battery is increased, a heat transfer path is provided, the thermal contact resistance in indirect cooling is reduced, and the temperature uniformity is greatly ensured.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and more specifically, to a lower housing device and a battery housing. Background Technology

[0002] With the rise of new energy technologies, the number of electric vehicles is increasing day by day. As a very critical component of electric vehicles, the battery pack mainly provides sufficient power for the electric vehicle to drive. The battery pack's shell structure includes an upper shell and a lower shell that are connected to each other. The upper shell and the lower shell form a mounting cavity for installing components such as power batteries, wiring harnesses, and copper busbars.

[0003] Currently, the casing structure is designed to only contact one side of the power battery. The limited contact area results in limited heat exchange capacity. In some special circumstances, this can lead to a large temperature difference, which in turn affects the vehicle's power performance and driving range. Summary of the Invention

[0004] The purpose of this application is to provide a lower housing device and a battery housing that can increase the contact area of ​​the power battery, provide a heat transfer path, reduce the thermal contact resistance in indirect cooling, and greatly ensure temperature uniformity.

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

[0006] In a first aspect, this application provides a lower housing device, comprising: a housing body having a receiving cavity configured to receive a plurality of power batteries; and a cooling structure having at least a portion thereof disposed in the receiving cavity, wherein the cooling structure is disposed between two adjacent power batteries and / or between the power batteries and the housing body for cooling the large surface of the power batteries.

[0007] In the above process, the main body of the enclosure houses the power battery, and the cooling structure is located in the cavity of the enclosure structure. The cooling structure can contact the large surface of the power battery, which can cool the power battery, increase the contact area of ​​the power battery, provide a heat transfer path, reduce the thermal contact resistance in indirect cooling, and greatly ensure temperature uniformity.

[0008] In some embodiments, the cooling structure includes a reinforcing mechanism and a buffering mechanism, the buffering mechanism covering the reinforcing mechanism, and at least a portion of the structure of the reinforcing mechanism being exposed at the periphery of the buffering mechanism.

[0009] In the above implementation process, the buffer mechanism covers the reinforcing mechanism, which can improve the overall structural rigidity. The reinforcing mechanism can be exposed outside the buffer mechanism, so that when the cooling machine structure comes into contact with the power battery, the buffer mechanism can play a buffering role during the handling and use of the power battery as well as during thermal expansion. While buffering the power battery, it can also absorb the deformation caused by the thermal expansion of the power battery, thereby improving safety.

[0010] In some embodiments, the reinforcing mechanism is configured as a mesh, such that the structure of the reinforcing mechanism exposed at the periphery of the buffer mechanism forms a plurality of spaced protrusions.

[0011] In the above process, when the cooling structure is placed in the cavity, the reinforcing mechanism is located on the periphery of the buffer mechanism and has several protrusions. This not only supports the overall structure but also conducts the heat generated by the power battery, providing a heat transfer path, reducing thermal contact resistance, ensuring temperature uniformity, and improving the safety and service life of the power battery.

[0012] In some embodiments, the height of the reinforcing mechanism is not higher than the height of the power battery. This facilitates processes such as wiring the power battery and ensures its normal operation.

[0013] In some embodiments, the lower housing device further includes a heat pipe structure disposed within the receiving cavity, and the heat pipe structure has a plurality of limiting grooves distributed along the front-rear direction, wherein the cooling structure and the power battery are both disposed within the limiting grooves.

[0014] In the above implementation process, the heat pipe structure is equipped with several limiting grooves for accommodating the power battery and cooling structure. This not only limits the power battery but also cools the front and rear sides of the power battery, increasing the heat dissipation area of ​​the power battery, improving thermal management efficiency, and making the temperature distribution uniform.

[0015] In some embodiments, the limiting grooves are configured to be distributed along a left-right direction, and a plurality of power batteries and cooling structures are provided along the left-right direction. The presence of a plurality of power batteries within the limiting grooves allows the power batteries to dissipate heat at different locations through the heat pipe structure and cooling structure, improving heat dissipation efficiency, reducing the complexity of the battery pack system, significantly reducing costs, and improving the installability of the power batteries.

[0016] In some embodiments, the limiting groove contacts the front and rear sides of the power battery, and the limiting groove is spaced apart from the front and rear sides of the cooling structure. The limiting groove can dissipate heat from the front and rear sides of the power battery, increasing the heat dissipation area of ​​the power battery, improving thermal management efficiency, and enhancing the safety of the power battery.

[0017] In some embodiments, the height of the limiting groove is not higher than the height of the power battery, which facilitates operations such as contacting the power battery and improves work efficiency.

[0018] In some embodiments, the lower housing device further includes a liquid cooling plate disposed at the lower end of the housing body, and the power battery, the heat pipe structure and the cooling structure are all in contact with the liquid cooling plate.

[0019] In the above process, the power battery, cooling structure, and heat pipe structure are all set on the liquid cooling plate, so that the liquid cooling plate can dissipate heat from the lower end of the power battery, while the heat from the cooling structure and heat pipe structure can also be transferred to the liquid cooling plate. The heat is carried away by the moving air, without the need for any power to dissipate heat, resulting in good heat dissipation effect and low cost.

[0020] Secondly, this application also provides a battery housing, characterized in that it includes a lower housing device as described in any of the preceding claims.

[0021] The battery housing provided in the second aspect of this application includes the lower housing device described in the first aspect of the technical solution, and therefore has all the technical effects of the above embodiments, which will not be repeated here.

[0022] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing embodiments of this application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For users of ordinary skills in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a lower housing device disclosed in an embodiment of this application.

[0025] Figure 2 This is a schematic diagram of the cooling structure of a lower housing device disclosed in an embodiment of this application.

[0026] Figure Labels

[0027] 100. Main body of the enclosure; 200. Cooling structure; 201. Reinforcing mechanism; 2011. Protrusion; 202. Buffer mechanism; 300. Heat pipe structure; 301. First heat pipe component; 302. Second heat pipe component; 303. Limiting groove; 400. Liquid cooling plate; 500. Power battery. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by users of ordinary skill in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this application, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only used to facilitate the description of this application and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0032] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0034] Example

[0035] At present, based on the maturity of technology and process and processing costs, the mainstream new energy vehicles at home and abroad all adopt the stamped liquid cooling plate solution based on the CTP structure of the power battery pack. This stamped liquid cooling plate solution has the advantages of high structural strength and high thermal management efficiency. Specifically: (1) In terms of structural strength, the use of stamped aluminum plate can better control the flatness, and the contact area with the module surface is large, and its thermal resistance is small, which improves the thermal management efficiency; (2) In terms of thermal management efficiency, the large contact area of ​​the flow channel can effectively reduce the temperature difference between the inside and outside of the battery cell, and provide better protection for the battery during rapid charging and discharging and low temperature preheating. In addition, the stamped liquid cooling plate is integrated as a separate part on the outside of the power battery pack, which saves space and reduces costs. Moreover, it can achieve dry and wet separation. If the coolant leaks, it will not come into contact with the module, busbar and other high-voltage components to form a short circuit, and will not cause the battery pack to short circuit and catch fire. In the long run, it is very beneficial to the development requirements of new energy vehicles.

[0036] During the design process, the inventors discovered that most current liquid cooling plates only contact one side of the battery cell. A battery cell is composed of multiple layers of materials (positive electrode, negative electrode, separator, and electrolyte), with resistance within each layer and contact resistance between layers, forming the battery's internal resistance. Inconsistencies between layers lead to variations in current flow and SOC (state of charge) for each layer, causing cell aging, lithium plating, and lifespan degradation, and in severe cases, thermal runaway. Furthermore, charging convenience is currently one of the main challenges hindering the development of new energy vehicles. Traditional liquid cooling plates, due to their limited contact area, have limited heat exchange capacity. Under conditions such as high-speed climbing and high-power fast charging, significant temperature differences occur, affecting vehicle performance and range. They also cannot meet the charging requirements of high-rate cells (4C and above), thus reducing product competitiveness.

[0037] In view of this, such as Figure 1As shown, in a first aspect, this application provides a lower housing device for placing a power battery 500 to fix and dissipate heat from the power battery 500. The lower housing device includes a housing body 100 and a cooling structure 200. The power battery 500 is disposed inside the housing body 100, and the cooling structure 200 is disposed inside the housing body 100 to contact the large surface of the power battery 500 to dissipate heat from the power battery 500.

[0038] Specifically, the housing body 100 has a receiving cavity configured to accommodate a plurality of power batteries 500; a cooling structure 200, at least a portion of which is disposed in the receiving cavity, and the cooling structure 200 is disposed between two adjacent power batteries 500 and / or between the power batteries 500 and the housing body 100, for cooling the large surface of the power batteries 500.

[0039] For example, the housing 100 can be made of extruded aluminum profile, and its structure can be divided into two functional areas: an electrical area and a cell area. The electrical area is used to install components such as BMS (Battery Management System) and BDU (Power Battery 500 Energy Distribution Unit). The cell area is used to house the power battery 500 and the cooling structure 200. The cooling structure 200 uses PCM (Phase Change Material), which mainly consists of paraffin wax, graphite, and a mesh structure. The thermal conductivity of paraffin wax is 0.2697 W / (m·K), and the thermal conductivity of graphite, a thermal conductivity enhancer, is 4-100 W / (m·K). By different formulation ratios, a composite thermal conductivity of 4-50 W / (m·K) can be formed, which fully meets the thermal management requirements of the cell under various operating conditions. To improve the structural mechanical properties and thermal conductivity of the PCM phase change material, a mesh structure is added to the PCM phase change material, and its material is composed of copper or other materials with good thermal conductivity.

[0040] In the above implementation process, the main body 100 of the housing contains the power battery 500, and the cooling structure 200 is disposed in the housing cavity of the housing structure. The cooling structure 200 can contact the large surface of the power battery 500, which can cool the power battery 500, increase the contact area of ​​the power battery 500, provide a heat transfer path, reduce the thermal contact resistance in indirect cooling, and greatly ensure temperature uniformity.

[0041] like Figure 2As shown, the cooling structure 200 includes a reinforcing mechanism 201 and a buffering mechanism 202. The buffering mechanism 202 covers the reinforcing mechanism 201, and at least a portion of the structure of the reinforcing mechanism 201 is exposed at the periphery of the buffering mechanism 202. Specifically, the cooling structure 200 uses enhanced PCM phase change material, which has good thermal runaway monitoring medium. To achieve the desired purpose, NTC sensors can be pre-embedded inside the cooling structure 200 to monitor the temperature of the power battery 500 in real time, providing a data basis for predicting thermal runaway of the power battery 500. The cooling structure 200 also acts as a flame retardant, serving as a fire extinguishing agent to suppress thermal runaway and improve the safety of the battery pack system. The reinforcing mechanism 201 uses materials with good thermal conductivity, such as copper. The buffer mechanism 202 can be made of insulating materials, providing insulation and safety, preventing high-voltage breakdown caused by particles falling between the two power batteries 500. Simultaneously, the buffer mechanism 202 also functions as a buffer pad, absorbing the deformation caused by the expansion of the power battery 500, ensuring safe use of the power battery 500 within its lifespan.

[0042] In the above implementation process, the buffer mechanism 202 covers the reinforcing mechanism 201, which can improve the overall structural rigidity. The reinforcing mechanism 201 can be exposed outside the buffer mechanism 202, so that when the cooling machine structure comes into contact with the power battery 500, the buffer mechanism 202 can play a buffering role during the handling and use of the power battery 500 and during thermal expansion. While buffering the power battery 500, it can also absorb the deformation of the power battery 500 due to thermal expansion, thereby improving safety.

[0043] In some embodiments, the reinforcing mechanism 201 is configured as a mesh, such that the structure of the reinforcing mechanism 201 exposed on the periphery of the buffer mechanism 202 forms a plurality of spaced protrusions 2011; it is understood that the reinforcing mechanism 201 can also be other structures, such as honeycomb, which can provide heat conduction and enhanced stability, and no special limitation is made here.

[0044] In the above implementation process, when the cooling structure 200 is placed in the receiving cavity, since the reinforcing mechanism 201 is located on the periphery of the buffer mechanism 202 and has several protrusions 2011, it can support the overall structure and conduct the heat generated by the power battery 500, provide a heat transfer path, reduce thermal contact resistance, ensure temperature uniformity, and improve the safety and service life of the power battery 500.

[0045] In some embodiments, the height of the reinforcing mechanism 201 is not higher than the height of the power battery 500. Preferably, the height of the reinforcing mechanism 201 is the same as the height of the power battery 500. This facilitates wiring and other processes of the power battery 500 and ensures its normal operation.

[0046] Please refer to again Figure 1 The lower housing device also includes a heat pipe structure 300, which is disposed in the receiving cavity and has a plurality of limiting grooves 303 distributed along the front-back direction. The cooling structure 200 and the power battery 500 are both disposed in the limiting grooves 303.

[0047] For example, the heat pipe structure 300 includes a first heat pipe component 301 and a second heat pipe component 302. The first heat pipe component 301 is distributed along the left-right direction, and a plurality of the first heat pipe components 301 are spaced apart along the front-back direction. The second heat pipe component 302 is disposed on the left and right sides of the first heat pipe component 301, and the second heat pipe component 302 is distributed along the front-back direction to enclose and form the limiting groove 303. The heat pipe structure 300 is provided with coolant, which can circulate through the coolant inside the heat pipe structure 300 to dissipate heat from the power battery 500.

[0048] In the above implementation process, the heat pipe structure 300 is provided with several limiting grooves 303 for accommodating the power battery 500 and the cooling structure 200. While limiting the power battery 500, it can also cool the front and rear sides of the power battery 500, increasing the heat dissipation area of ​​the power battery 500, improving the thermal management efficiency, and making the temperature distribution uniform.

[0049] In some embodiments, the limiting grooves 303 are configured to be distributed along the left-right direction, and a plurality of power batteries 500 and cooling structures 200 are provided along the left-right direction. The multiple power batteries 500 disposed within the limiting grooves 303 allow the power batteries 500 to dissipate heat at different locations through the heat pipe structure 300 and cooling structure 200, improving heat dissipation efficiency, reducing the complexity of the battery pack system, significantly reducing costs, and improving the installability of the power batteries 500.

[0050] It should be noted that the coolant in the heat pipe structure 300 can circulate along its entire structure, or an independent cooling circulation system can be set up for the front and rear sides of the power battery 500. That is, one power battery 500 is set up with an independent coolant circulation system, and the coolant circulation systems of two adjacent power batteries 500 do not interfere with each other.

[0051] In some embodiments, the limiting groove 303 contacts the front and rear sides of the power battery 500, and the limiting groove 303 is spaced apart from the front and rear sides of the cooling structure 200. The limiting groove 303 can dissipate heat from the front and rear sides of the power battery 500, increasing the heat dissipation area of ​​the power battery 500, improving thermal management efficiency, and enhancing the safety of the power battery 500.

[0052] In some embodiments, the height of the limiting groove 303 is not higher than the height of the power battery 500, which facilitates the contact operation of the power battery 500 and other processes, and improves work efficiency.

[0053] In some embodiments, the lower housing device further includes a liquid cooling plate 400, which is disposed at the lower end of the housing body 100, and the power battery 500, the heat pipe structure 300, and the cooling structure 200 are all in contact with the liquid cooling plate 400. It can be understood that through the cooperation of the liquid cooling plate 400, the heat pipe structure 300, and the cooling structure 200, heat dissipation can be achieved on all five sides of the power battery 500, greatly improving the heat dissipation effect of the power battery 500.

[0054] In the above implementation process, the power battery 500, cooling structure 200 and heat pipe structure 300 are all mounted on the liquid cooling plate 400, so that the liquid cooling plate 400 can dissipate heat from the lower end of the power battery 500, while the heat from the cooling structure 200 and heat pipe structure 300 can also be transferred to the liquid cooling plate 400. Heat is carried away by the moving air, without the need for any power source, resulting in good heat dissipation effect and low cost.

[0055] Secondly, this application also provides a battery housing, characterized in that it includes a lower housing device as described in any of the preceding claims. Exemplarily, the battery housing further includes an upper housing device, which is disposed above the lower housing device and fixedly connected to it.

[0056] The battery housing provided in the second aspect of this application includes the lower housing device described in the first aspect of the technical solution, and therefore has all the technical effects of the above embodiments, which will not be repeated here.

[0057] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A lower housing device, characterized in that, include: The main body of the housing has a receiving cavity configured to accommodate a plurality of power batteries; A cooling structure, at least a portion of which is disposed in the receiving cavity, and the cooling structure is disposed between two adjacent power batteries and between the power battery and the main body of the housing, for cooling the large surface of the power battery; The cooling structure includes a reinforcing mechanism and a buffering mechanism, wherein the buffering mechanism covers the reinforcing mechanism, and at least a portion of the structure of the reinforcing mechanism is exposed at the periphery of the buffering mechanism; The reinforcing mechanism is configured as a mesh, so that the structure of the reinforcing mechanism exposed at the periphery of the buffer mechanism forms a number of spaced protrusions; The cooling structure includes an enhanced PCM phase change material, which comprises paraffin, graphite, and a mesh structure. The cooling structure has an embedded NTC sensor.

2. The lower housing device according to claim 1, characterized in that, The height of the reinforcing mechanism is not higher than the height of the power battery.

3. The lower housing device according to claim 1, characterized in that, The lower housing device also includes a heat pipe structure, which is disposed within the receiving cavity. The heat pipe structure has several limiting grooves distributed along the front-to-back direction. The cooling structure and the power battery are both disposed within the limiting grooves. Coolant is disposed inside the heat pipe structure.

4. The lower housing device according to claim 3, characterized in that, The limiting grooves are configured to be distributed along the left and right direction, and the power battery and the cooling structure are provided with a plurality of such grooves along the left and right direction.

5. The lower housing device according to claim 3, characterized in that, The limiting groove contacts the front and rear sides of the power battery, and the limiting groove is spaced apart from the front and rear sides of the cooling structure.

6. The lower housing device according to claim 5, characterized in that, The height of the limiting groove is not higher than the height of the power battery.

7. The lower housing device according to claim 3, characterized in that, The lower housing device also includes a liquid cooling plate, which is disposed at the lower end of the housing body, and the power battery, the heat pipe structure and the cooling structure are all in contact with the liquid cooling plate.

8. A battery case, characterized in that, Includes the lower housing device as described in any one of claims 1-7.

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