A semi-submerged battery pack

Abstract

The utility model relates to the technical field of battery pack discloses a kind of semi-submersible battery packs, including shell and multiple electric cores, multiple electric cores are housed in the shell, liquid cooling layer and air layer are sequentially arranged in the shell from bottom to upwards and are isolated from each other, a part of multiple electric cores is located in the liquid cooling layer and also located in the air layer, the air layer is at positive pressure relative to the liquid cooling layer to prevent the coolant in the liquid cooling layer from leaking to the air layer direction;Through the synergistic effect of liquid cooling layer and air layer, the heat conduction efficiency can be greatly improved, and the temperature distribution uniformity of multiple electric cores is effectively controlled, solving the problem of local overheating;The battery pack of the present scheme is particularly suitable for application in high energy density required scene, realizes comprehensive optimization in heat dissipation performance, sealing reliability, cost control and life extension etc., and shows broad application prospect.

Description

Technical Field

[0001] This utility model relates to the technical field of battery packs, and more particularly to a semi-immersed battery pack. Background Technology

[0002] Currently, liquid cooling technology for battery packs mainly employs two mainstream solutions: the first is an indirect liquid cooling solution using metal liquid cooling plates for the battery cells, and the second is a solution using full immersion of the battery cells in coolant. Both of these liquid cooling solutions currently have the following problems:

[0003] Firstly, the contradiction between efficiency and cost is difficult to reconcile. For the first type of liquid cooling solution mentioned above, this solution mostly improves heat exchange efficiency by optimizing the internal flow channel design of the liquid cooling plate (such as serpentine, multi-branch, or layered structure). However, the liquid cooling plate needs to pass through multiple layers of media such as the cell surface, thermal interface material, and liquid cooling plate wall, resulting in a large overall thermal resistance, which limits the heat dissipation efficiency. It is necessary to rely on high thermal conductivity interface materials or complex flow channel design to improve performance, but such optimization significantly increases manufacturing costs. For the second type of liquid cooling solution, although the full immersion solution of coolant achieves efficient heat dissipation by directly contacting the cell, it requires a large amount of expensive dielectric coolant and a high-strength sealing structure, which leads to a significant increase in system cost and weight.

[0004] Secondly, the thermal management response speed is insufficient. For the first liquid cooling solution, the heat conduction path of the indirect liquid cooling plate delays the real-time temperature control. Especially under extreme conditions such as thermal runaway, the coolant cannot directly contact the heat source and needs to rely on external auxiliary systems (such as spray devices) for intervention, which increases the risk of failure. For the second liquid cooling solution, although the coolant full immersion solution can absorb heat quickly, the active circulation system it relies on may cause a response lag due to valve or pump failure under sudden conditions.

[0005] Third, system compatibility and space utilization are limited. For the first liquid cooling solution, the liquid cooling plate has high requirements for the spatial layout of the battery pack, and installation gaps and fixing devices need to be reserved, which limits the compactness of the cell arrangement and thus affects the cell arrangement density and energy density. For the second liquid cooling solution, the fully immersed coolant solution requires the design of redundant boxes due to the large volume of coolant, which further compresses the available space.

[0006] Fourth, the uniformity of heat dissipation is insufficient. For the first liquid cooling solution, the long heat dissipation path of the liquid cooling plate leads to insufficient uniformity of heat dissipation for the battery cells, that is, some battery cells may overheat. For the second liquid cooling solution, although the design of complete immersion of coolant can enhance heat dissipation, the complete encapsulation of the battery cells by the coolant will hinder the efficient transfer of heat, thus there will still be some relatively overheated battery cells. In other words, the temperature uniformity of each battery cell is also insufficient, making it difficult to meet the high requirements for temperature uniformity of each battery cell.

[0007] Overall, while existing liquid cooling technologies have made breakthroughs in heat dissipation capabilities, they are limited by thermal resistance, cost, and system complexity, making it difficult to meet the comprehensive requirements of lightweight, economic efficiency, and reliability for small power battery packs. Furthermore, the temperature uniformity among multiple cells is insufficient when cooling multiple cells. In addition, both of the aforementioned liquid cooling solutions face long-term reliability issues, such as fatigue cracking of weld seams in the liquid cooling plate and aging failure of sealing materials, which can lead to coolant leakage or decreased insulation performance. These problems collectively restrict the large-scale application of liquid cooling technology in small power batteries. Therefore, innovative designs are urgently needed for small battery packs to overcome the multiple bottlenecks in heat dissipation efficiency, heat dissipation uniformity, cost, and reliability. Utility Model Content

[0008] This utility model provides a semi-immersed battery pack, which mainly solves the technical problem of how to make the battery pack have high heat dissipation efficiency, high heat dissipation uniformity and low cost at the same time.

[0009] To achieve the above objectives, this utility model provides the following technical solution:

[0010] A semi-submersible battery pack includes a housing and a plurality of battery cells, wherein the plurality of battery cells are housed within the housing. The housing contains a liquid cooling layer and an air layer that are isolated from each other, arranged sequentially from bottom to top. A portion of the plurality of battery cells is located both within the liquid cooling layer and within the air layer. The air layer is under positive pressure relative to the liquid cooling layer to prevent coolant in the liquid cooling layer from leaking toward the air layer.

[0011] In one of the technical solutions, the semi-immersed battery pack further includes a first plate and a second plate;

[0012] Both the first plate and the second plate are connected inside the housing. The bottom surface of the first plate and the inner wall of the housing together form the liquid cooling layer. The second plate is disposed on the top of the first plate and together with the inner wall of the housing and the first plate, they form the air layer. The first plate is provided with a plurality of through holes for the battery cell to pass through. The second plate is provided with a plurality of through holes for the battery cell to pass through.

[0013] In one of the technical solutions, the semi-immersed battery pack further includes a protective film, which is laid on the bottom surface of the first plate and also covers the surface of the liquid cooling layer. The protective film is provided with a plurality of through-holes for the battery cells to pass through.

[0014] In one technical solution, a first sealing ring is compressed between the outer ring of the first plate and the inner wall of the outer shell, and a second sealing ring is compressed between the outer ring of the second plate and the inner wall of the outer shell.

[0015] In one of the technical solutions, a retaining edge is provided on the inner wall of the outer shell, and the retaining edge is located below the second plate and within the air layer.

[0016] In one of the technical solutions, the second plate is provided with a through gas injection hole, and an intake regulating valve with an automatic closing function is connected to the gas injection hole.

[0017] In one of the technical solutions, the semi-immersed battery pack further includes foam, which is disposed on the side of the second plate facing away from the air layer, and the foam is provided with a plurality of through-holes for the battery cells to pass through.

[0018] In one of the technical solutions, the first plate is snapped to the inner wall of the outer shell, and the second plate is also snapped to the inner wall of the outer shell.

[0019] In one of the technical solutions, multiple battery cells are connected in series at the top of the liquid cooling layer away from the liquid cooling layer.

[0020] In one of the technical solutions, the outer shell is an injection-molded plastic part, and the bottom of the outer shell is provided with a plurality of mounting holes, each of which is used for inserting one of the battery cells.

[0021] Compared with the prior art, the semi-immersed battery pack provided by this utility model has at least the following beneficial effects:

[0022] In terms of heat dissipation, this battery pack solution significantly improves thermal conductivity through the synergistic effect of the semi-immersed liquid cooling layer and air layer, effectively controlling the temperature distribution uniformity of multiple cells and solving the problem of localized overheating. Regarding sealing performance, the multi-layered sealing structure provides a reliable level of protection. Combined with the gas regulation mechanism within the air layer, it ensures the sealing of the coolant inside the liquid cooling layer, enhances system safety, and greatly extends maintenance cycles. Furthermore, the integrated plastic shell reduces the overall weight of the battery pack, simplifies the assembly process, and lowers production costs. In addition, this battery pack solution effectively prevents coolant evaporation and corrosion of electrical connections, extending the battery pack's lifespan. Simultaneously, the foam cushioning ensures stable system operation in vibration environments. This battery pack solution is particularly suitable for applications requiring high energy density, achieving comprehensive optimization in heat dissipation, sealing reliability, cost control, and lifespan extension, demonstrating broad application prospects. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a semi-immersed battery pack provided in an embodiment of this application;

[0025] Figure 2 A cross-sectional view of a semi-submersible battery pack provided in an embodiment of this application;

[0026] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;

[0027] Figure 4 This is an exploded view of the structure of a semi-immersed battery pack provided in an embodiment of this application.

[0028] Figure label:

[0029] 1. Outer shell; 11. Mounting hole; 12. Edge retainer; 2. Battery cell; 3. Liquid cooling layer; 4. Air layer; 5. Electrical connector; 6. First plate; 61. First clearance hole; 7. Second plate; 71. Second clearance hole; 72. Gas injection hole; 8. First sealing ring; 9. Second sealing ring; 10. Protective film; 101. Third clearance hole; 20. Foam; 201. Fourth clearance hole. Detailed Implementation

[0030] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0031] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0032] It should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0033] Furthermore, 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0034] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0035] Please refer to the following: Figures 1 to 4 This utility model provides a semi-submersible battery pack, mainly comprising a shell 1 and multiple battery cells 2. The shell 1 is a one-piece injection-molded plastic part, which has the advantage of being lightweight and is very suitable for use in small battery packs. Multiple mounting holes 11 are provided at the bottom of the shell 1, and one battery cell 2 is inserted into each mounting hole 11. The battery cell 2 is preferably a cylindrical battery cell. More specifically, the interior of the shell 1 has a liquid cooling layer 3 and an air layer 4 arranged sequentially from bottom to top, which are mutually isolated. A portion of the multiple battery cells 2 is located within the air layer 4, and a portion of the multiple battery cells 2 is also located within the air layer 4. Furthermore, the air layer 4 is under a slight positive pressure relative to the liquid cooling layer 3, that is, the air pressure in the air layer 4 is greater than the gas pressure inside the liquid cooling layer 3. The multiple battery cells 2 are connected in series at their top ends away from the liquid cooling layer 3 by electrical connectors 5, which can be metal busbars or aluminum wires.

[0036] Specifically, this solution uses a plastic outer shell 1 with a topless design and bottom mounting holes 11 optimized for fixing the battery cells 2, which simplifies the assembly process of the battery cells 2 and ensures the stability of the battery cell installation. This solution utilizes the submerged coolant in the liquid cooling layer 3 to directly contact the surfaces of multiple battery cells 2, thereby quickly absorbing the heat of multiple battery cells 2. At the same time, the positive pressure air layer 4 set above the liquid cooling layer 3 can effectively prevent the coolant inside the liquid cooling layer 3 from leaking outward, and the air layer 4 can also facilitate the efficient heat transfer between multiple battery cells 2. In other words, due to the synergistic effect of the liquid cooling layer 3 and the air layer 4, it has the advantages of efficient cooling of multiple battery cells 2 and can also improve the temperature uniformity of multiple battery cells 2, thereby solving the problem of local overheating inside the battery pack.

[0037] Please refer to them again. Figures 1 to 4 The semi-immersed battery pack of this solution also includes a first plate 6 and a second plate 7. Both the first plate 6 and the second plate 7 are connected inside the outer casing 1. The bottom surface of the first plate 6 and the inner wall of the outer casing 1 together form the liquid cooling layer 3 mentioned above. The second plate 7 is disposed on top of the first plate 6, and the second plate 7, together with the inner wall of the outer casing 1 and the first plate 6, forms the air layer 4 mentioned above. The first plate 6 is provided with a plurality of through first clearance holes 61, and the second plate 7 is provided with a plurality of through second clearance holes 71. Both the first clearance holes 61 and the second clearance holes 71 are used for the power cells 2 to pass through, so as to avoid multiple power cells 2. As can be seen from the above, the arrangement of the first plate 6 and the second plate 7 is beneficial to the formation of the liquid cooling layer 3 and the air layer 4 mentioned above. Preferably, the second plate 7 is provided with a through gas injection hole 72, and an air intake regulating valve with an automatic closing function is connected to the gas injection hole 72. By providing this gas injection hole 72, gas can be injected into the air layer 4. By providing the air intake regulating valve, the air pressure in the air layer 4 can be easily adjusted to a preset air pressure value.

[0038] Please refer to the following: Figures 2 to 4 The semi-immersed battery pack of this embodiment also includes a protective film 10, which is laid on the bottom surface of the first plate 6. The protective film 10 has multiple through-holes 101 for the power cells 2 to pass through, thus avoiding interference with the multiple cells 2. Furthermore, the protective film 10 also covers the surface of the coolant in the liquid cooling layer 3. The protective film 10 can be made of a high-temperature resistant and corrosion-resistant polymer material. The main function of the protective film 10 is to isolate the coolant in the liquid cooling layer 3 from direct contact with the air layer 4, preventing coolant evaporation and oxidation, while ensuring that heat can be smoothly conducted upwards.

[0039] Please refer to them again. Figures 2 to 4To further prevent coolant leakage within the liquid cooling layer 3, a first sealing ring 8 is preferably provided between the outer ring of the first plate 6 and the inner wall of the outer shell 1, and a second sealing ring 9 is preferably provided between the outer ring of the second plate 7 and the inner wall of the outer shell 1. During installation, the first plate 6 can be fixed to the inner wall of the outer shell 1 by a snap-fit ​​connection, compressing the first sealing ring 8. Similarly, the second plate 7 can be fixed to the inner wall of the outer shell 1 by a snap-fit ​​connection, compressing the second sealing ring 9. In fact, the aforementioned protective film 10 can be regarded as the first sealing structure to prevent coolant leakage, the first sealing ring 8 and the first plate 6 can be regarded as the second sealing structure to prevent coolant leakage, and the second sealing ring 9 and the second plate 7 can be regarded as the third sealing structure to prevent coolant leakage. The triple sealing protection can effectively prevent coolant from seeping upward into the electrical connection parts. In addition, the second sealing ring 9 is also used to prevent air leakage from the air layer 4, ensuring that the air layer 4 can be in a slightly positive pressure environment. Preferably, a retaining edge 12 is provided on the inner wall of the outer casing 1. The retaining edge 12 is located below the second plate 7. In fact, the retaining edge 12 is also located within the air layer 4. The retaining edge 12 can further prevent coolant from leaking upward.

[0040] Please refer to them again. Figures 2 to 4 The semi-immersed battery pack of this embodiment also includes foam 20, which is disposed on the side of the second plate 7 facing away from the air layer 4. Foam 20 has a plurality of through fourth clearance holes 201, which are used for the power cell 2 to pass through, so as to avoid the power cell 2. Foam 20 can absorb mechanical vibration and also help seal the surrounding area of ​​the gas injection hole 72.

[0041] In summary, the battery pack of this solution significantly improves heat dissipation efficiency due to the synergistic effect of the semi-immersed liquid cooling layer 3 and the air layer 4, effectively controlling the temperature distribution uniformity of multiple cells 2 and solving the problem of localized overheating. Regarding sealing performance, the multi-layer sealing structure provides a reliable protection level. Combined with the gas regulation mechanism within the air layer 4, it ensures the sealing of the coolant inside the liquid cooling layer 3, enhances system safety, and greatly extends the maintenance cycle. Furthermore, the integrated plastic shell 1 reduces the overall weight of the battery pack, simplifies the assembly process, and lowers production costs. In addition, the battery pack effectively prevents coolant evaporation and corrosion of electrical connections, extending the battery pack's lifespan. Simultaneously, the cushioning protection of the foam 20 ensures stable system operation in vibration environments. This battery pack solution is particularly suitable for applications requiring high energy density, achieving comprehensive optimization in heat dissipation performance, sealing reliability, cost control, and lifespan extension, demonstrating broad application prospects.

[0042] The above are merely preferred embodiments of the present utility model, and only specifically describe the technical principles of the present utility model. These descriptions are only for explaining the principles of the present utility model and should not be construed as limiting the scope of protection of the present utility model in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model, as well as other specific embodiments of the present utility model that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of the present utility model.

Claims

1. A semi-immersed battery pack, characterized in that, The device includes a housing and multiple battery cells, with the multiple battery cells housed within the housing. The housing contains, from bottom to top, a liquid cooling layer and an air layer that are isolated from each other. A portion of the multiple battery cells is located both within the liquid cooling layer and within the air layer. The air layer is under positive pressure relative to the liquid cooling layer to prevent the coolant in the liquid cooling layer from leaking towards the air layer.

2. The semi-immersed battery pack as described in claim 1, characterized in that, The semi-immersed battery pack also includes a first plate and a second plate; Both the first plate and the second plate are connected inside the housing. The bottom surface of the first plate and the inner wall of the housing together form the liquid cooling layer. The second plate is disposed on the top of the first plate and together with the inner wall of the housing and the first plate, they form the air layer. The first plate is provided with a plurality of through holes for the battery cell to pass through. The second plate is provided with a plurality of through holes for the battery cell to pass through.

3. The semi-immersed battery pack as described in claim 2, characterized in that, The semi-immersed battery pack also includes a protective film, which is laid on the bottom surface of the first plate and also covers the surface of the liquid cooling layer. The protective film has a plurality of through-holes for the battery cells to pass through.

4. The semi-immersed battery pack as described in claim 2, characterized in that, A first sealing ring is compressed between the outer ring of the first plate and the inner wall of the outer shell, and a second sealing ring is compressed between the outer ring of the second plate and the inner wall of the outer shell.

5. The semi-immersed battery pack as described in claim 4, characterized in that, The inner wall of the outer shell is provided with a circumferential flange, which is located below the second plate and within the air layer.

6. The semi-immersed battery pack as described in claim 2, characterized in that, The second plate has a through gas injection hole, and an intake regulating valve is connected to the gas injection hole.

7. The semi-immersed battery pack as described in claim 2, characterized in that, The semi-immersed battery pack also includes foam, which is disposed on the side of the second plate facing away from the air layer, and the foam is provided with a plurality of through-holes for the battery cells to pass through.

8. The semi-immersed battery pack as described in claim 2, characterized in that, The first plate is snapped to the inner wall of the outer shell, and the second plate is also snapped to the inner wall of the outer shell.

9. The semi-immersed battery pack as described in claim 1, characterized in that, Multiple battery cells are connected in series at the top of the cell, away from the liquid cooling layer.

10. The semi-immersed battery pack as described in claim 1, characterized in that, The outer casing is an injection-molded plastic part, and the bottom of the outer casing is provided with multiple mounting holes, each of which is used for inserting one of the battery cells.

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