Liquid cooling plate and battery pack

Abstract

This invention relates to the field of battery technology, and more particularly to a liquid cooling plate and a battery pack. The liquid cooling plate is disposed at the upper or lower end of a battery module. The battery module includes the liquid cooling plate, which has a cavity. At least one flow channel is spaced apart within the cavity along a second direction. The length direction of the flow channel is parallel to a first direction, and its width direction is parallel to the second direction. Multiple battery cells arranged in a row along the first direction are positioned opposite one flow channel. The width of the flow channel gradually decreases from the middle to both sides along its length direction. The battery pack includes the aforementioned liquid cooling plate. The liquid cooling plate is designed to widen the flow channels according to the temperature distribution of the battery cells at different locations within the battery module. This allows the flow channels to achieve differentiated cooling for the cells at different locations. Cells with higher temperatures have wider flow channels with stronger cooling effects, while cells with lower temperatures have narrower flow channels with weaker cooling effects. This reduces the temperature difference between the cells at different locations and improves the temperature uniformity of the battery module.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a liquid cooling plate and a battery pack. Background Technology

[0002] Temperature rise and temperature uniformity within a battery module are important indicators for evaluating the power supply performance, safety performance, and stability of a battery pack. In a battery module, individual battery cells are connected in series or parallel to form the module. The module is placed on a liquid cooling plate, and cooling is achieved by circulating coolant through equal-width channels within the plate.

[0003] The different positions of the individual cells within the battery module result in varying heat dissipation effects. For example, cells located in the middle of the battery module experience poor heat dissipation and thus have higher temperatures; while cells at the ends and sides of the module dissipate heat quickly and have relatively lower temperatures. Existing liquid cooling plates have uniformly distributed flow channels of the same size, providing the same cooling effect to each cell. This leads to poor temperature uniformity among the cells, severely impacting the battery pack's lifespan. Summary of the Invention

[0004] The purpose of this invention is to provide a liquid cooling plate and a battery pack to perform differentiated cooling of cells at different locations within the battery module, reduce the temperature difference between the cells within the battery module, and improve the temperature uniformity of the battery module.

[0005] To achieve this objective, the technical solution adopted by the present invention is as follows:

[0006] A liquid cooling plate is disposed at the upper or lower end of the battery module, the battery module comprising a plurality of battery cells arranged in an array along a first direction and a second direction;

[0007] The liquid cooling plate has a cavity, and at least one flow channel is provided at intervals along the second direction in the cavity. The length direction of the flow channel is parallel to the first direction and its width direction is parallel to the second direction. Each column of multiple cells arranged along the first direction is directly opposite to one of the flow channels. The width of the flow channel gradually decreases from the middle of its length direction to both sides.

[0008] As a preferred embodiment, at least three flow channels are provided at intervals along the second direction inside the liquid cooling plate, and the width of the at least three flow channels at the same position gradually decreases from the middle of the second direction to both sides.

[0009] As a preferred embodiment, the flow channel includes two side plates symmetrically arranged along the centerline of its width direction. The outline of the side plates is a stepped structure that gradually decreases from the middle to both sides in its length direction, so that the flow channel forms a plurality of sequentially connected rectangular cavities.

[0010] As a preferred embodiment, each column of multiple battery cells arranged along the first direction is respectively positioned directly opposite the corresponding rectangular cavity;

[0011] The lengths of the multiple rectangular cavities within the same flow channel are equal, and the widths of the multiple rectangular cavities gradually decrease from the middle of the flow channel along its length direction to both sides.

[0012] As a preferred embodiment, the flow channel includes two side plates symmetrically arranged along its centerline along its length direction. The profile of the side plates is a smooth curve that gradually slopes downward from the middle of its length direction to both sides, so that the flow channel forms a spindle-shaped cavity.

[0013] As a preferred embodiment, the flow channel has an inlet and an outlet at both ends along its length, and each of the flow channels extends through both ends along its length to the outside of the cavity on both sides along the first direction.

[0014] As a preferred embodiment, the inlet size of at least three of the flow channels gradually decreases from the middle to both sides in the second direction; the outlet size of at least three of the flow channels gradually decreases from the middle to both sides in the second direction.

[0015] As a preferred embodiment, at least two flow channels are provided at intervals along the second direction within the cavity;

[0016] The cavity of the liquid cooling plate is spaced apart by at least one partition along the second direction to divide the cavity into at least two cooling chambers, and each flow channel is located in the corresponding cooling chamber.

[0017] As a preferred embodiment, a support plate is provided at the centerline position along the width direction of each flow channel, and the support plate extends along the length direction of the flow channel to both sides of the cavity along the first direction.

[0018] The battery pack includes the aforementioned liquid cooling plate.

[0019] The beneficial effects of this invention are as follows:

[0020] The liquid cooling plate proposed in this invention is positioned at the top or bottom of the battery module. Since the temperature of multiple battery cells arranged along a first direction in the battery module gradually decreases from the center to both sides, each row of multiple battery cells arranged along the first direction is positioned directly opposite a flow channel of the liquid cooling plate. The width of the flow channel gradually decreases from the center to both sides along its length, resulting in a gradual decrease in the cooling effect of the flow channel from the center to both sides along its length. The liquid cooling plate is designed to widen the flow channel according to the temperature distribution of the battery cells at different locations within the battery module. This allows the flow channel to achieve differentiated cooling for the battery cells at different locations; that is, the flow channel corresponding to the higher temperature cell has a larger width and a stronger cooling effect, while the flow channel corresponding to the lower temperature cell has a smaller width and a weaker cooling effect. This reduces the temperature difference between the battery cells at different locations within the battery module and improves the temperature uniformity of the battery module.

[0021] The battery pack proposed in this invention includes the aforementioned liquid cooling plate. The liquid cooling plate has a widened flow channel design based on the temperature distribution of the cells at different locations within the battery module. This allows the flow channel to achieve differentiated cooling for the cells at different locations. Specifically, the flow channel corresponding to the cell with a higher temperature has a wider width and a stronger cooling effect, while the flow channel corresponding to the cell with a lower temperature has a smaller width and a weaker cooling effect. This reduces the temperature difference between the cells at different locations within the battery module, improves the temperature uniformity of the battery module, and extends the service life of the battery pack. Attached Figure Description

[0022] Figure 1 This is a top view of the battery module provided in Embodiment 1 of the present invention;

[0023] Figure 2 This is a schematic diagram of the liquid cooling plate provided in Embodiment 1 of the present invention;

[0024] Figure 3 This is a cross-sectional view of the liquid cooling plate provided in Embodiment 1 of the present invention;

[0025] Figure 4 This is a cross-sectional view of the liquid cooling plate provided in Embodiment 2 of the present invention.

[0026] The component names and labels in the diagram are as follows:

[0027] 10. Battery cell; 20. Liquid cooling plate;

[0028] 1. Cavity; 2. Flow channel; 21. Side plate; 22. Inlet; 23. Outlet; 3. Support plate; 4. Partition. Detailed Implementation

[0029] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0030] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] This embodiment proposes a battery pack, which includes a battery management system (BMS), battery modules, and a liquid cooling plate. The BMS controls the charging and discharging of the battery modules. The liquid cooling plate is located at the top or bottom of the battery modules to cool the cells within the modules, ensuring the battery pack remains within a suitable temperature range. This battery pack can serve as a power battery for electric vehicles and can also be used in other devices; no specific limitations are specified here.

[0036] like Figure 1 As shown, the battery module includes multiple battery cells 10 arranged in an array along a first direction and a second direction, and the multiple battery cells 10 are connected in series or in parallel. In the figure, the X direction is the first direction, and the Y direction is the second direction.

[0037] In the battery module, the individual cells 10 are located in different positions, resulting in varying heat dissipation effects. Cells 10 located in the middle of the battery module experience poor heat dissipation and have higher temperatures; while cells 10 located at the ends and sides of the battery module dissipate heat quickly and have relatively lower temperatures. Specifically, each column arranged along the first direction ( Figure 1 The temperature of the horizontal column of cells 10 gradually decreases from the middle to both sides along the first direction.

[0038] The existing liquid cooling plate has uniformly distributed flow channels of the same size inside to produce the same cooling effect on each cell 10. This results in poor temperature uniformity among the cells 10, which seriously affects the service life of the battery pack.

[0039] To solve the above problems, such as Figure 2 and Figure 3 As shown, this embodiment also proposes a liquid cooling plate 20, which is disposed at the upper or lower end of the battery module. The liquid cooling plate 20 has a cavity 1, and at least one flow channel 2 is disposed at intervals along the second direction in the cavity 1. The length direction of the flow channel 2 is parallel to the first direction and its width direction is parallel to the second direction. Multiple cells 10 arranged in each column along the first direction are directly opposite to one flow channel 2. The width of the flow channel 2 gradually decreases from the middle of its length direction to both sides.

[0040] In this embodiment, the width of the flow channel 2 gradually decreases from the middle to both sides along its length, thus gradually reducing the cooling effect of the flow channel 2 from the middle to both sides along its length. The liquid cooling plate 20 is designed to widen the flow channel 2 according to the temperature distribution of the cells 10 at different locations within the battery module, enabling the flow channel 2 to achieve differentiated cooling for the cells 10 at different locations. That is, the flow channel 2 corresponding to the cell 10 with a higher temperature has a larger width and a stronger cooling effect, while the flow channel 2 corresponding to the cell 10 with a lower temperature has a smaller width and a weaker cooling effect. This reduces the temperature difference of the cells 10 at different locations within the battery module, improves the temperature uniformity of the battery module, and extends the service life of the battery pack.

[0041] When the battery module has only two horizontal rows of cells 10, that is, the battery module has two rows of cells 10 arranged along the first direction. At this time, the temperature distribution of the two horizontal rows of cells 10 is basically the same. The inner cavity of the liquid cooling plate 20 has two flow channels 2 with the same structure. The two flow channels 2 are distributed at intervals along the second direction and are respectively opposite to one of the horizontal rows of cells 10.

[0042] It should be noted that when the battery module has at least three horizontal columns of cells 10, that is, when the battery module has at least three rows of cells 10 arranged along the first direction, each column arranged along the second direction ( Figure 1 In the vertical column of the battery cell 10, the temperature gradually decreases from the center to both sides along the second direction. Correspondingly, at least three flow channels 2 are spaced apart along the second direction within the liquid cooling plate 20. The width of the at least three flow channels 2 at the same position gradually decreases from the center to both sides of the second direction. That is, among the multiple flow channels 2, the width of the flow channel 2 located in the middle of the second direction is the largest at the same position, while the width of the flow channels 2 located on both sides of the second direction is the smallest at the same position. By widening the width of the multiple flow channels 2 at the same position along the second direction, the liquid cooling plate enables the multiple flow channels 2 to achieve differentiated cooling based on the temperature distribution of the battery cells 10 at different positions within the battery module. Specifically, the width of the flow channel 2 at the same position corresponding to the battery cell 10 with a higher temperature in the vertical column is larger, resulting in a stronger cooling effect, while the width of the flow channel 2 corresponding to the battery cell 10 with a lower temperature in the vertical column is smaller, resulting in a weaker cooling effect. This further reduces the temperature difference of the battery cells 10 at different positions within the battery module, further improves the temperature uniformity of the battery module, and further extends the service life of the battery pack.

[0043] Specifically, such as Figure 3 As shown, this embodiment is illustrated by having three flow channels 2 within the liquid cooling plate 20. The width of a designated position of the flow channel 2 located in the middle of the second direction is D1. The flow channels 2 located on both sides of the second direction have the same structure and the width of the same designated position is D2, where D1 > D2.

[0044] When the battery module has four horizontal columns, the liquid cooling plate 20 has four flow channels 2 distributed along the second direction. The two flow channels 2 located in the middle of the second direction have the same structure and a width of D1 at a specified position. The two flow channels 2 located on either side of the second direction have the same structure and a width of D2 at the same specified position, where D1 > D2. Similarly, when the liquid cooling plate 20 has three or more flow channels 2, the flow channel 2 located in the middle of the second direction is D1. When the number of flow channels 2 in the liquid cooling plate 20 is an odd number p (p≥5), there is one flow channel 2 located in the middle of the second direction; when the number of flow channels 2 in the liquid cooling plate 20 is an even number q (q≥4), there are two flow channels 2 located in the middle of the second direction. In the second direction, two flow channels 2 symmetrically distributed with respect to the flow channel 2 located in the middle have the same structure and a width of Dn (n≥3) at the same specified position, where D1 > D2 > ... > Dn.

[0045] Furthermore, such as Figure 3 As shown, the flow channel 2 includes two side plates 21 symmetrically arranged along the centerline of its width direction. The outline of the side plates 21 is a stepped structure that gradually decreases from the middle to both sides in its length direction, so that the flow channel 2 forms multiple sequentially connected rectangular cavities. By setting the side plates 21 into a stepped structure, the processing and manufacturing of the flow channel 2 is facilitated, and the processing difficulty of the liquid cooling plate 20 is reduced.

[0046] Specifically, multiple battery cells 10 arranged in each column along the first direction are respectively positioned opposite to their corresponding rectangular cavities. The lengths of the rectangular cavities within the same flow channel 2 are equal, and the widths of the rectangular cavities gradually decrease from the center of the flow channel 2 towards both sides. Each horizontal column of battery cells 10 corresponds one-to-one with the rectangular cavities in its corresponding flow channel 2, allowing for cooling of battery cells 10 at different temperatures through rectangular cavities of varying areas. The width of the rectangular cavity varies with the heat dissipation of the battery cells 10. When the battery cells 10 dissipate heat quickly (i.e., at low temperatures), the smaller the width (i.e., the area) of the rectangular cavity, the worse the cooling effect. Conversely, when the battery cells 10 dissipate heat slowly (i.e., at high temperatures), the larger the width (i.e., the area) of the rectangular cavity, the better the cooling effect. This reduces the temperature difference between the individual battery cells 10 and achieves temperature uniformity in the battery module.

[0047] It should be noted that the length H of the rectangular cavity in each flow channel 2 in this embodiment is the same and is approximately equal to the thickness of the battery cell 10, so that each battery cell 10 can be precisely aligned with a rectangular cavity, avoiding multiple rectangular cavities cooling the same battery cell 10.

[0048] like Figure 2 and Figure 3As shown, the flow channel 2 has an inlet 22 and an outlet 23 at both ends along its length, and each flow channel 2 extends through both ends along its length to the outside of the cavity 1 on both sides along the first direction. The flow channel 2 is connected to the external circulation pipe through the inlet 22 and the outlet 23, respectively. The cooling medium (generally cooling water) in the external circulation pipe flows into the corresponding flow channel 2 through multiple inlets 22, and then flows back into the circulation pipe from multiple outlets 23, realizing the circulation cooling process of the liquid cooling plate 20. Since the circulation pipe is existing technology, it will not be described in detail here.

[0049] In this embodiment, due to the widened design of the flow channel 2, the capacity of each flow channel 2 gradually decreases from the center to both sides along the second direction, that is, the flow rate of the cooling medium entering each flow channel 2 gradually decreases from the center to both sides along the second direction. Figure 3 As shown, the inlet 22 dimensions of at least three flow channels 2 gradually decrease from the center to both sides in the second direction, and the outlet 23 dimensions of at least three flow channels 2 also gradually decrease from the center to both sides in the second direction. Based on the volume of cooling medium that each flow channel 2 can hold, the outlet 23 and inlet 22 dimensions of each flow channel 2 are adaptively designed to ensure smooth flow of the cooling medium within each flow channel 2, avoiding blockages or insufficient flow, and improving the cooling effect of the liquid cooling plate 20.

[0050] Specifically, since the liquid cooling plate 20 is a rectangular flat plate, the inlet 22 and outlet 23 of each flow channel 2 have the same height, while the inlet 22 and outlet 23 of the flow channel 2 have different widths. For example... Figure 3 As shown, the width L1 of the inlet 22 and outlet 23 of the flow channel 2 located in the middle of the second direction, and the width L2 of the inlet 22 and outlet 23 of the flow channels 2 located on both sides of the second direction, are shown, with L1 > L2. It is understood that the various dimensions of the flow channel 2 (D1, D2, H, L1 and L2, etc.) need to be adaptively adjusted according to the temperature of the battery cell 10, the size of the liquid cooling plate 20, etc., and are not specifically limited here.

[0051] Furthermore, such as Figure 3 As shown, a support plate 3 is provided at the center line along the width direction of each flow channel 2, and the support plate 3 extends along the length direction of the flow channel 2 to both sides of the cavity 1 along the first direction. Since the interior of the flow channel 2 is a hollow structure, the support plate 3 improves the structural strength of the flow channel 2, thereby improving the overall structural strength of the liquid cooling plate 20, preventing the flow channel 2 from denting or leaking, and improving safety.

[0052] Furthermore, at least two flow channels 2 are spaced apart along the second direction within the cavity 1. The cavity 1 of the liquid cooling plate 20 is spaced apart by at least one partition 4 along the second direction to divide the cavity 1 into at least two cooling chambers, with each flow channel 2 located within a corresponding cooling chamber. Because the liquid cooling plate 20 has a cavity 1, the partition 4 improves the structural strength and load-bearing capacity of the liquid cooling plate 20, preventing dents or damage to the liquid cooling plate 20 and enhancing safety.

[0053] Example 2

[0054] This embodiment proposes a liquid cooling plate and a battery pack. The structure of the liquid cooling plate and the battery pack is basically the same as that of the liquid cooling plate and the battery pack in Embodiment 1. The only difference is that the outer contour of the side plate 21 of the flow channel 2 is different.

[0055] like Figure 4 As shown, the flow channel 2 in this embodiment includes two side plates 21 symmetrically arranged along its centerline along its length. The profile of the side plates 21 is a smooth curve that gradually slopes downward from the middle of its length to both sides, so that the flow channel 2 forms a spindle-shaped cavity. By smoothing the side plates 21, the profile of the flow channel 2 is optimized, improving the control accuracy of the cooling effect of each cell 10, further reducing the temperature difference of each cell 10 in the battery module, so that the temperature of each cell 10 after cooling is close or basically consistent, thus extending the service life of the battery pack.

[0056] Specifically, a logarithmic function can be used to smooth the contour of the side plate 21 of the flow channel 2.

[0057]

[0058] Where l is the length of a single flow channel 2, which is a constant. k is a correction parameter, which can be adjusted according to the design scheme of the flow channel 2 in the liquid cooling plate 20. To prevent the values ​​of a and b from exceeding the normal range, let 25≤k≤100.

[0059] c1 is the widest width of flow channel 2, generally taken as the width at the middle position of flow channel 2 along the first direction, which is the design value. c2 is the narrowest width of flow channel 2, generally taken as the width at both ends of flow channel 2 along the first direction, which is the design value. a and b can be solved by the above system of equations.

[0060] Then according to the equation 0≤x≤l / 2, the design curve is obtained. This curve is only a local curve of the flow channel 2. Then, through operations such as mirroring and chamfering, the complete outline of the side plate 21 of the flow channel 2 is obtained.

[0061] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquid cold plate characterized by, The battery module is disposed at the upper or lower end of the battery module, and the battery module includes a plurality of battery cells (10) arranged in an array along a first direction and a second direction. The liquid cooling plate has a cavity (1), and at least three flow channels (2) are spaced apart in the cavity (1) along the second direction. The length direction of the flow channel (2) is parallel to the first direction and its width direction is parallel to the second direction. Each column of multiple cells (10) arranged along the first direction is positioned opposite to one of the flow channels (2). The width of the flow channel (2) gradually decreases from the middle of its length direction to both sides. The flow channel (2) has an inlet (22) and an outlet (23) at both ends along its length direction, and each flow channel (2) extends through both ends along its length direction to the outside of the cavity (1) along the first direction. The width of at least three of the flow channels (2) at the same location gradually decreases from the middle to both sides in the second direction; the size of the inlet (22) of at least three of the flow channels (2) gradually decreases from the middle to both sides in the second direction; the size of the outlet (23) of at least three of the flow channels (2) gradually decreases from the middle to both sides in the second direction.

2. The liquid cold plate of claim 1, wherein, The flow channel (2) includes two side plates (21) symmetrically arranged along the center line of its width direction. The outline of the side plate (21) is a stepped structure that gradually decreases from the middle to both sides in its length direction, so that the flow channel (2) forms a plurality of sequentially connected rectangular cavities.

3. The liquid cold plate of claim 2, wherein, Each column of multiple battery cells (10) arranged along the first direction is respectively positioned opposite to the corresponding rectangular cavity; The lengths of the multiple rectangular cavities within the same flow channel (2) are equal, and the widths of the multiple rectangular cavities gradually decrease from the middle of the flow channel (2) along its length direction to both sides.

4. The liquid cold plate of claim 1, wherein, The flow channel (2) includes two side plates (21) symmetrically arranged along the center line of its length direction. The outline of the side plates (21) is a smooth curve that gradually slopes downward from the middle of its length direction to both sides, so that the flow channel (2) forms a spindle-shaped cavity.

5. The liquid cold plate of claim 1, wherein, The cavity (1) of the liquid cooling plate is spaced at least two partitions (4) along the second direction to divide the cavity (1) into at least three cooling chambers, each of the flow channels (2) being located in the corresponding cooling chamber.

6. The liquid cold plate of any of claims 1-5, wherein, A support plate (3) is provided at the center line position along the width direction of each flow channel (2), and the support plate (3) extends along the length direction of the flow channel (2) to both sides of the cavity (1) along the first direction.

7. A battery pack, characterized by Includes the liquid cooling plate according to any one of claims 1 to 6.

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