Liquid cooling plate and battery pack

Abstract

The utility model provides a kind of liquid cooling plate and battery pack.The liquid cooling plate includes: liquid cooling substrate, is equipped with sequentially intercommunication and is used for the inlet, flow channel and outlet for cooling medium flow;Stress buffer structure, along the length direction of liquid cooling substrate, at least one end of liquid cooling substrate is equipped with stress buffer structure, stress buffer structure is structured as can occur bending deformation.The technical scheme of the utility model solves the problem that the liquid cooling plate in the prior art is prone to warping due to cell expansion.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery technology, and more specifically, to a liquid cooling plate and a battery pack. Background Technology

[0002] Common battery thermal management solutions can generally be divided into two types: air cooling and liquid cooling. Liquid cooling is the mainstream thermal management solution for power batteries, and most liquid cooling solutions involve placing a liquid cooling plate on the bottom of the battery. This solution is relatively mature and reliable. The advantage of this solution is that the cooling plate can be integrated with the battery casing, simultaneously providing sealing, support, and thermal management. However, more and more batteries now need to meet the charging requirements of 4C or higher rates. The bottom-mounted liquid cooling solution has a long heat transfer path, which cannot effectively remove the heat generated by the battery cells. Excessively high cell temperatures will significantly affect the cell's cycle life.

[0003] Therefore, solutions with higher cooling efficiency are needed, such as large-area cooling of the battery cells. This involves placing liquid cooling plates on the large surface of the battery cells, relying on the large heat exchange area and short heat transfer path to achieve higher cooling efficiency. A common large-area liquid cooling solution involves placing liquid cooling plates between each row of battery cells. The liquid cooling plates are connected by special connectors, and a heat-conducting medium connects the liquid cooling plates to the large surface of the battery cells. Along the normal direction of the large surface of the battery cells, the sequence is: liquid cooling plate, heat-conducting medium, battery cell, heat-conducting medium, liquid cooling plate, heat-conducting medium, and the next row of battery cells. These layers must also be stacked in this order, and finally, they are pressed into the battery box using tooling.

[0004] During charge-discharge cycles, battery cells expand and contract, with the primary deformation direction perpendicular to the cell's surface (thickness direction). For high-rate applications such as 4C supercharging, the main solution to meet thermal management requirements is large-area liquid cooling, where liquid cooling plates are placed between the large surfaces of the cells in close contact. Because the cells and liquid cooling plates are compressed into the battery pack, when the cells expand, they directly compress the cooling plates, causing internal stress. Liquid cooling plates are typically made of aluminum alloy, and the inner wall of the battery pack restricts their length. This periodic stress generated by cell expansion can easily concentrate at the fixing points or edges of the cooling plates, potentially causing warping. This affects the contact between the cooling plates and the cells, resulting in poor heat dissipation. Utility Model Content

[0005] The main objective of this invention is to provide a liquid cooling plate and a battery pack to solve the problem that liquid cooling plates in the prior art are prone to warping due to cell expansion.

[0006] To achieve the above objectives, the present invention provides a liquid cooling plate, comprising: a liquid cooling substrate having an inlet, a flow channel, and an outlet connected in sequence for supplying a cooling medium; and a stress buffer structure having a stress buffer structure at least one end of the liquid cooling substrate along the length direction of the liquid cooling substrate, the stress buffer structure being configured to undergo bending deformation.

[0007] Furthermore, the stress buffer structure includes one or more arc-shaped plates, which are arranged sequentially along the length of the liquid-cooled substrate. The bending directions of two adjacent arc-shaped plates are opposite and they are smoothly connected.

[0008] Furthermore, the thickness of the curved plate is less than the thickness of the liquid-cooled substrate to form a deformable region capable of deformation.

[0009] Furthermore, the thickness of the curved plate is between 50% and 80% of the thickness of the liquid-cooled substrate.

[0010] Furthermore, the stress buffer structure is smoothly connected to the liquid-cooled substrate.

[0011] Furthermore, the stress buffer structure is made of the same material as the liquid-cooled substrate; or, the stress buffer structure is made of an alloy whose material ductility is higher than that of the liquid-cooled substrate.

[0012] Furthermore, the stress buffer structure is integrally formed with the liquid-cooled substrate.

[0013] According to another aspect of the present invention, the present invention provides a battery pack, including at least one cell module and a plurality of the above-mentioned liquid cooling plates, wherein the plurality of liquid cooling plates are spaced apart along the thickness direction of the liquid cooling plates, and a cell module is disposed between two adjacent liquid cooling plates, and the liquid cooling plates are used to cool the cell module.

[0014] Furthermore, the battery module includes at least one battery cell, and the dimension of the liquid-cooled substrate in the height direction is larger than 50% of the height dimension of the battery cell.

[0015] Furthermore, the battery pack also includes a thermally conductive medium, with the liquid cooling plate and the cell module filled with the thermally conductive medium.

[0016] By applying the technical solution of this utility model, a stress buffer structure is provided at the end of the liquid-cooled substrate. The stress buffer structure is different from the flexible deformation structure of the liquid-cooled substrate. When the liquid-cooled plate is subjected to stress caused by the expansion of the battery cell, it can absorb the strain force generated by the liquid-cooled plate through elastic or plastic deformation, thereby reducing the overall stress peak of the liquid-cooled substrate and thus playing a role in protecting the liquid-cooled substrate. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings: Figure 1 A schematic diagram of an embodiment of the battery pack of this utility model is shown; Figure 2 It shows Figure 1 A top view of the battery pack; Figure 3 It shows Figure 1 A schematic diagram of the exploded structure of the battery pack; Figure 4 It shows Figure 1 A schematic diagram of the liquid cooling plate of the battery pack.

[0018] The above figures include the following reference numerals: 1. Liquid-cooled substrate; 2. Thermally conductive medium; 3. Battery cell; 4. Current collector; 5. Stress buffer structure; 6. Battery cell module; 7. Liquid-cooled plate. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] like Figures 1 to 4 As shown, an embodiment of the present invention provides a liquid cooling plate, including: a liquid cooling substrate 1, having an inlet, a flow channel and an outlet connected in sequence for supplying cooling medium; and a stress buffer structure 5, which is provided at least one end of the liquid cooling substrate 1 along the length direction of the liquid cooling substrate 1, and the stress buffer structure 5 is configured to be able to undergo bending deformation.

[0021] In the above technical solution, a stress buffer structure 5 is provided at the end of the liquid-cooled substrate 1. The stress buffer structure 5 is different from the flexible deformation structure of the liquid-cooled substrate 1. When the liquid-cooled plate is subjected to stress caused by the expansion of the battery cell, it can absorb the strain force generated by the liquid-cooled plate through elastic or plastic deformation, so as to reduce the overall stress peak of the liquid-cooled substrate 1 and thus play the role of protecting the liquid-cooled substrate 1.

[0022] Furthermore, it can eliminate stress peaks in the liquid cooling plate, especially in the weld area, preventing cracking and leakage caused by metal fatigue.

[0023] In some embodiments, the stress buffer structure 5 is located at the end of the liquid-cooled substrate 1. It can be provided at one end of the liquid-cooled substrate 1 or at both ends of the liquid-cooled substrate 1. The specific number of such structures depends on the space and structure of the battery pack.

[0024] It should be noted that the length, thickness and height of the liquid cooling plate are set perpendicularly to each other, with the thickness direction being the normal to the large surface of the battery cell, that is, perpendicular to the large surface of the battery cell.

[0025] It should be noted that the flow channels inside the liquid-cooled substrate 1 can be used for the flow of cooling medium to achieve the liquid cooling function.

[0026] like Figures 1 to 4 As shown in the embodiment of this utility model, the stress buffer structure 5 includes one or more arc-shaped plates. The multiple arc-shaped plates are arranged sequentially along the length direction of the liquid-cooled substrate 1. The bending directions of two adjacent arc-shaped plates are opposite and they are smoothly connected.

[0027] With the above configuration, the strain of the liquid-cooled substrate 1 can be absorbed by bending or unfolding the arc plate, so as to effectively absorb the stress generated by the liquid-cooled substrate 1, thereby protecting the liquid-cooled substrate 1 and improving the reliability of the liquid-cooled plate; at the same time, the smooth connection between two adjacent arc plates can avoid the generation of new stress concentration areas due to uneven transition.

[0028] The liquid cooling plate structure of this utility model embodiment is easy to implement, does not require changes to the main structure of the existing battery pack, and does not affect the thermal management effect and sealing function of the liquid cooling plate.

[0029] like Figures 1 to 4 As shown in the embodiment of this utility model, the thickness of the arc-shaped plate is less than the thickness of the liquid-cooled substrate 1, so as to form a deformation area capable of deformation. In this way, the strain of the liquid-cooled substrate 1 can be absorbed through deformation, thereby protecting the liquid-cooled substrate 1.

[0030] like Figures 1 to 4 As shown in the embodiment of this utility model, the thickness of the arc-shaped plate is between 50% and 80% of the thickness of the liquid-cooled substrate 1. This avoids the problem of easy breakage caused by a thin arc-shaped plate, and also avoids the problem of insufficient stress absorption due to small deformation of the arc-shaped plate.

[0031] In some embodiments, the stress buffer structure 5 is wavy or serpentine in shape, and the thickness of the area is reduced to 50%-80% of the thickness of the liquid-cooled substrate 1 by machining or chemical etching, forming an area that is prone to deformation, so as to effectively absorb the strain of the liquid-cooled substrate 1 and thus protect the liquid-cooled substrate 1.

[0032] like Figures 1 to 4 As shown in the embodiment of this utility model, the stress buffer structure 5 is smoothly connected to the liquid-cooled substrate 1. This avoids the formation of new stress concentration areas due to excessive unevenness.

[0033] It should be noted that the smooth connection between the stress buffer structure 5 and the liquid-cooled substrate 1 means that these two parts are not simply spliced ​​together at right angles or abruptly, but are naturally integrated in geometric shape through a certain arc or curve. This is mainly to avoid the formation of stress peaks at the connection when the expansion of the battery cell generates stress on the liquid-cooled plate, because sharp corners often lead to abnormal increases in local stress, which may cause material damage under long-term action.

[0034] like Figures 1 to 4 As shown in the embodiment of this utility model, the stress buffer structure 5 and the liquid-cooled substrate 1 are made of the same material; this facilitates welding and ensures that the coefficients of thermal expansion are the same, so as to prevent cracking at the connection between the stress buffer structure 5 and the liquid-cooled substrate 1.

[0035] In some embodiments, the stress buffer structure 5 is made of an alloy whose material ductility is higher than that of the liquid-cooled substrate 1.

[0036] like Figures 1 to 4 As shown in the embodiment of this utility model, the stress buffer structure 5 and the liquid-cooled substrate 1 are integrally formed. The stress buffer structure 5 and the liquid-cooled substrate 1 can be integrally formed from the substrate of the liquid-cooled substrate 1, or the stress buffer structure 5 can be processed separately and then welded to the liquid-cooled substrate 1. In this way, the integration is high, the stress buffer structure 5 and the liquid-cooled substrate 1 can be integrally formed without additional parts, and the assembly complexity is not increased.

[0037] like Figures 1 to 4 As shown, an embodiment of this utility model provides a battery pack, including at least one cell module 6 and multiple liquid cooling plates 7 as described above. The multiple liquid cooling plates 7 are spaced apart along the thickness direction of the liquid cooling plates 7, and the cell module 6 is disposed between two adjacent liquid cooling plates 7. The liquid cooling plates 7 are used to cool the cell module 6. In this way, the cell module 6 can be cooled.

[0038] like Figures 1 to 4 As shown in the embodiment of this utility model, the battery module 6 includes at least one battery cell 3, and the dimension of the liquid-cooled substrate 1 in the height direction is 50% larger than the height dimension of the battery cell 3. This ensures sufficient heat exchange area to improve heat exchange efficiency.

[0039] like Figures 1 to 4 As shown in the embodiment of this utility model, the battery pack further includes a thermally conductive medium 2, and the space between the liquid cooling plate 7 and the cell module 6 is filled with the thermally conductive medium 2. In this way, the heat of the cell module 6 can be transferred to the liquid cooling plate 7 through the thermally conductive medium 2 to dissipate heat from the cell module 6.

[0040] In some embodiments, the space between the liquid cooling plate 7 and the large surface of the battery cell 3 is filled with a thermally conductive medium 2, which can be a thermally conductive gel, a thermally conductive structural adhesive, or a thermally conductive pad.

[0041] like Figures 1 to 4 As shown in the embodiment of this utility model, the battery pack also includes a current collector 4. Along the length direction of the liquid cooling plate, the current collector 4 is located at one end of the liquid cooling plate, and the cell module 6 is electrically connected to the current collector 4.

[0042] As can be seen from the above description, the above-described embodiments of this utility model achieve the following technical effects: a stress buffer structure is provided at the end of the liquid-cooled substrate. The stress buffer structure is different from the flexible deformation structure of the liquid-cooled substrate. When the liquid-cooled plate is subjected to stress caused by the expansion of the battery cell, it can absorb the strain force generated by the liquid-cooled plate through elastic or plastic deformation, so as to reduce the overall stress peak of the liquid-cooled substrate and thus play a role in protecting the liquid-cooled substrate.

[0043] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A liquid-cooled plate, characterized in that, include: The liquid-cooled substrate (1) is provided with an inlet, a flow channel and an outlet connected in sequence for the flow of cooling medium; The stress buffer structure (5) is provided at least one end of the liquid cooling substrate (1) along the length direction of the liquid cooling substrate (1), and the stress buffer structure (5) is configured to be able to undergo bending deformation.

2. The liquid cooling plate according to claim 1, characterized in that, The stress buffer structure (5) includes one or more arc-shaped plates, and the multiple arc-shaped plates are arranged sequentially along the length direction of the liquid-cooled substrate (1). The bending directions of two adjacent arc-shaped plates are opposite and they are smoothly connected.

3. The liquid cooling plate according to claim 2, characterized in that, The thickness of the arc-shaped plate is less than the thickness of the liquid-cooled substrate (1) to form a deformable region capable of deformation.

4. The liquid cooling plate according to claim 3, characterized in that, The thickness of the arc-shaped plate is between 50% and 80% of the thickness of the liquid-cooled substrate (1).

5. The liquid-cooled plate according to any one of claims 1 to 4, characterized in that, The stress buffer structure (5) is smoothly connected to the liquid-cooled substrate (1).

6. The liquid-cooled plate according to any one of claims 1 to 4, characterized in that, The stress buffer structure (5) is made of the same material as the liquid-cooled substrate (1); or, the stress buffer structure (5) is made of an alloy whose material ductility is higher than that of the liquid-cooled substrate (1).

7. The liquid-cooled plate according to any one of claims 1 to 4, characterized in that, The stress buffer structure (5) is integrally formed with the liquid-cooled substrate (1).

8. A battery pack, characterized in that, It includes at least one battery cell module (6) and a plurality of liquid cooling plates (7) according to any one of claims 1 to 7, wherein the plurality of liquid cooling plates (7) are spaced apart along the thickness direction of the liquid cooling plates (7), and the battery cell module (6) is disposed between two adjacent liquid cooling plates (7) among the plurality of liquid cooling plates (7), and the liquid cooling plates (7) are used to cool the battery cell module (6).

9. The battery pack according to claim 8, characterized in that, The battery module (6) includes at least one battery cell (3), and the dimension of the liquid-cooled substrate (1) in the height direction is 50% larger than the height dimension of the battery cell (3).

10. The battery pack according to claim 8, characterized in that, The battery pack also includes a thermally conductive medium (2), which is filled between the liquid cooling plate (7) and the cell module (6).

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