Double-layer liquid-cooled battery pack

Abstract

The utility model discloses a double-layer liquid-cooled battery pack, which comprises a liquid-cooled box cover, a liquid-cooled box cover, a liquid-cooled box cover, a liquid-cooled box cover and a liquid-cooled box cover, the liquid cooling box cover is assembled on the liquid cooling bottom plate, and a battery space is formed between the liquid cooling box cover and the liquid cooling bottom plate; the battery module is arranged in the battery space; the first heat conduction layer is arranged between the battery module and the liquid cooling top plate; the second heat conduction layer is arranged between the battery module and the liquid cooling bottom plate, and the liquid cooling top plate and the liquid cooling bottom plate are arranged at the top and the bottom of the battery module respectively, so that heat generated by the battery module can be absorbed and taken away more effectively; wherein the liquid cooling top plate and the middle frame are integrally designed to form the liquid cooling box cover, so that the stability and the reliability of the structure are improved, and meanwhile, the assembly process is omitted, thereby avoiding the problem of non-uniform torsion when the liquid cooling bottom plate is assembled in a traditional mode.

Description

Technical Field

[0001] This utility model relates to the field of battery pack technology, and in particular to a double-layer liquid-cooled battery pack. Background Technology

[0002] In recent years, the charge and discharge rates of battery packs have significantly improved. While this technological advancement has enhanced the range and fast charging capabilities of electric vehicles, it has also brought new challenges. Specifically, high charge and discharge rates cause the battery pack to generate a large amount of heat during the charging and discharging process. If this heat cannot be released effectively and in a timely manner, it will cause the cell temperature to become too high, which will not only affect the operating efficiency of the battery pack but also severely shorten the battery's lifespan and even lead to safety issues.

[0003] To address this issue, traditional technologies commonly employ a double-layer liquid cooling plate design, placing one liquid cooling plate at the top and one at the bottom of the battery cell. Coolant circulation removes the heat generated by the cell. While this design improves heat dissipation efficiency to some extent, it also introduces new problems. First, the need to install liquid cooling plates on both the top and bottom of the cell significantly increases the number of bolts required, raising manufacturing costs and complicating battery pack assembly. Second, during installation of the bottom liquid cooling plate, the bolts are affected by the top liquid cooling plate and its fixing structure, making it difficult to achieve a perfectly vertical fit. This results in uneven bolt torque, affecting the tight contact between the liquid cooling plate and the cell, and hindering heat transfer efficiency. Inaccurate torque can also cause bolts to loosen or break, further impacting the reliability and safety of the battery pack. Utility Model Content

[0004] To overcome at least one of the defects described in the prior art, this utility model provides a double-layer liquid-cooled battery pack. This avoids the torsional effect of the liquid-cooled top plate installation on the liquid-cooled bottom plate, thereby preventing assembly errors and unevenness issues with the liquid-cooled bottom plate.

[0005] The technical solution adopted by this utility model to solve its problem is:

[0006] A dual-layer liquid-cooled battery pack includes: a liquid-cooled tank cover, the liquid-cooled tank cover including an integrally connected middle frame and a liquid-cooled top plate; a liquid-cooled bottom plate, the liquid-cooled tank cover being assembled on the liquid-cooled bottom plate, and a battery space being formed between the liquid-cooled tank cover and the liquid-cooled bottom plate; a battery module, the battery module being disposed within the battery space; a first thermally conductive layer, the first thermally conductive layer being disposed between the battery module and the liquid-cooled top plate; and a second thermally conductive layer, the second thermally conductive layer being disposed between the battery module and the liquid-cooled bottom plate.

[0007] By adopting the above solution, liquid cooling top plate and liquid cooling bottom plate are respectively set at the top and bottom of the battery module, the heat generated by the battery module can be absorbed and carried away more effectively. The liquid cooling top plate is integrated with the middle frame to form a liquid cooling box cover, which improves the stability and reliability of the structure, and eliminates the assembly process, thereby avoiding the problem of uneven torque that exists when assembling the liquid cooling bottom plate in the traditional method.

[0008] Further, the liquid-cooled top plate includes: a top plate; a bottom plate, the bottom plate being disposed opposite to the top plate; a surrounding plate, the surrounding plate surrounding the edge between the top plate and the bottom plate to form a liquid-cooled tank for containing coolant, the surrounding plate being provided with a coolant inlet and a coolant outlet communicating with the liquid-cooled tank; and fins, the fins being disposed in the liquid-cooled tank to form a plurality of liquid-cooled flow channels from the coolant inlet to the coolant outlet.

[0009] By adopting the above scheme, the enclosure not only seals off the liquid cooling tank but also provides a coolant inlet and outlet, allowing the coolant to smoothly enter and exit the tank, forming a complete coolant circulation path. Fins are installed inside the liquid cooling tank, dividing it into multiple liquid cooling channels flowing from the coolant inlet to the outlet, simplifying manufacturing. The fin design increases the contact area between the coolant and the liquid cooling top plate, improving heat transfer efficiency. Simultaneously, the multiple liquid cooling channels allow for more even distribution of coolant within the tank, further enhancing heat dissipation performance.

[0010] Furthermore, the liquid cooling channels are U-shaped and arranged in parallel with each other.

[0011] By adopting the above scheme, the coolant can be more evenly distributed within the liquid cooling tank due to the parallel arrangement of each U-shaped liquid cooling channel. This uniform distribution avoids localized overheating or insufficient cooling, improves the uniformity and efficiency of heat dissipation, and solves the problem of excessive heat generation in the battery pack at high charge / discharge rates.

[0012] Furthermore, one side of the enclosure is provided with a first connecting plate and a second connecting plate extending outward at intervals. The coolant inlet is provided on the first connecting plate, and the coolant outlet is provided on the second connecting plate. The bottom plate is provided with a first mounting plate corresponding to the first connecting plate, and the bottom plate is provided with a second mounting plate corresponding to the second connecting plate. The top plate is provided with a first cover plate corresponding to the first connecting plate, and the top plate is provided with a second cover plate corresponding to the second connecting plate.

[0013] By adopting the above scheme, the first connecting plate and the second connecting plate provide installation positions for the coolant inlet and coolant outlet. The first assembly plate and the first cover plate clamp the first connecting plate, and the second assembly plate and the second cover plate clamp the second connecting plate, thereby improving the edge sealing of the coolant inlet and coolant outlet.

[0014] Furthermore, the first assembly plate is equipped with a liquid cooling inlet pipe facing the liquid cooling base plate, and the liquid cooling inlet pipe is connected to the coolant inlet. The second assembly plate is equipped with a liquid cooling outlet pipe facing the liquid cooling base plate, and the liquid cooling outlet pipe is connected to the coolant outlet.

[0015] By adopting the above scheme, the coolant enters the liquid cooling tank through the liquid cooling inlet pipe, flows along the liquid cooling channel and absorbs heat, then flows out through the coolant outlet and back to the coolant supply system for recooling. This circulation method improves heat dissipation efficiency and ensures the temperature stability of the battery module at high charge and discharge rates. Both the liquid cooling inlet pipe and the liquid cooling outlet pipe face the liquid cooling base plate. This design helps to reduce the vertical height of the liquid cooling top plate, thereby improving the overall compactness of the battery pack. Both the liquid cooling inlet pipe and the liquid cooling outlet pipe are directly mounted on the assembly plate, simplifying the assembly process.

[0016] Furthermore, the middle frame includes a first middle frame sidewall and a thickened wall distributed in a stepped manner. The thickened wall is disposed on the side of the first middle frame sidewall near the liquid-cooled top plate. The thickened wall is aligned with the side of the first middle frame sidewall facing the battery space. The side of the thickened wall facing out of the battery space protrudes from the first middle frame sidewall. The thickened wall is welded to the liquid-cooled top plate.

[0017] By adopting the above solution, the strength and rigidity of the middle frame in the connection area with the liquid-cooled top plate are enhanced, which can effectively alleviate structural deformation; the thickened wall can also increase the welding area with the liquid-cooled top plate, thereby improving welding stability and firmness.

[0018] Furthermore, a first middle frame lip plate is provided on the side of the first middle frame sidewall near the liquid-cooled base plate, and the first middle frame lip plate is assembled and connected to the liquid-cooled base plate.

[0019] By adopting the above scheme, the design of the first middle frame lip plate enhances the overall structural strength of the middle frame, making the battery pack more stable and reliable when subjected to various external pressures. At the same time, it ensures that the liquid cooling base plate can be accurately installed on the middle frame, improves the connection sealing, and guarantees the structural stability and heat dissipation performance of the entire battery pack.

[0020] Furthermore, the first middle frame sidewall, the thickened wall, and the first middle frame lip plate are integrally extruded.

[0021] By adopting the above scheme, aluminum alloy is extruded in a mold under high temperature and high pressure to form parts with specific shapes and sizes, which has the advantages of high production efficiency, high material utilization, high part dimensional accuracy, and good surface quality; it also reduces potential defects caused by welding, bolting and other processes, and improves the structural strength and stability of the battery pack.

[0022] Furthermore, the middle frame includes an integrally bent second middle frame top wall and a second middle frame side wall, the second middle frame top wall being welded to the liquid-cooled top plate.

[0023] By adopting the above-mentioned solution, combining the integrated bending forming process with welding connection technology, the production efficiency of battery packs can be significantly improved. Integrated bending forming reduces the processing steps and assembly time of parts, while welding connection simplifies the connection process and reduces production costs.

[0024] Furthermore, an integrally bent second middle frame lip plate is provided on the side wall of the second middle frame near the liquid-cooled base plate, and the second middle frame lip plate is assembled and connected to the liquid-cooled base plate.

[0025] By adopting the above solution, through the design of integral bending and assembly connection, the connection between the second middle frame lip plate and the liquid-cooled base plate is more compact and reliable, reducing potential failures caused by loose connections or leakage, and improving the reliability and stability of the battery pack.

[0026] In summary, the double-layer liquid-cooled battery pack provided by this utility model has the following technical effects:

[0027] 1. The dual-layer liquid cooling design, with a liquid-cooled top plate and a liquid-cooled bottom plate at the top and bottom of the battery module respectively, can more effectively absorb and dissipate the heat generated by the battery module during charging and discharging. This design significantly improves heat dissipation efficiency, helps reduce cell temperature, extends battery life, and improves the operating efficiency of the battery pack;

[0028] 2. The liquid-cooled top plate and the middle frame are integrated to form the liquid-cooled tank cover. This integrated design improves the stability and reliability of the structure. Compared with the traditional design where the liquid-cooled top plate and bottom plate are installed separately, this utility model avoids the complexity and potential errors in the assembly process, thereby improving the overall performance and safety of the battery pack.

[0029] 3. The assembly process between the liquid cooling tank cover and the liquid cooling base plate is simplified. Since the liquid cooling top plate is already integrated with the middle frame, there is no need to install the liquid cooling top plate separately. This reduces assembly steps and the number of required connectors, lowers manufacturing costs, and improves production efficiency.

[0030] 4. In traditional designs, the bottom liquid cooling plate is easily affected by the top liquid cooling plate and its fixing structure during installation, resulting in uneven application of bolt torque. This invention avoids this problem through the integrated design of the liquid cooling top plate and the middle frame. The liquid cooling tank cover is assembled as a single structure onto the liquid cooling bottom plate, ensuring uniform application of bolt torque, thereby improving the tight contact between the liquid cooling plate and the battery cell and enhancing heat transfer efficiency. Attached Figure Description

[0031] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present utility model;

[0032] Figure 2 This is a partial exploded structural diagram of an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the liquid cooling tank cover structure according to an embodiment of the present utility model;

[0034] Figure 4 This is an exploded structural diagram of the liquid cooling tank cover according to an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the internal structure of the liquid-cooled top plate according to an embodiment of the present invention;

[0036] Figure 6 This is a partial cross-sectional schematic diagram of a liquid cooling tank cover according to an embodiment of the present utility model;

[0037] Figure 7 This is a partial cross-sectional schematic diagram of another liquid cooling tank cover according to an embodiment of the present utility model.

[0038] The meanings of the reference numerals in the attached drawings are as follows: 1. Liquid cooling tank cover; 11. Middle frame; 111. First middle frame side wall; 112. Thickened wall; 113. First middle frame lip plate; 114. Second middle frame top wall; 115. Second middle frame side wall; 116. Second middle frame lip plate; 12. Liquid cooling top plate; 121. Top plate; 1211. First cover plate; 1212. Second cover plate; 122. Bottom plate; 1221. First assembly plate; 1222. Second assembly plate; 1223. Liquid cooling inlet. 1. Pipe; 1224. Liquid cooling outlet pipe; 123. Enclosure plate; 1231. First connecting plate; 1232. Second connecting plate; 124. Liquid cooling tank; 125. Coolant inlet; 126. Coolant outlet; 127. Fin; 128. Liquid cooling channel; 2. Liquid cooling base plate; 21. Liquid inlet; 22. Liquid outlet; 3. Battery module; 31. CCS module; 32. Cell assembly; 33. Battery management system; 34. Socket unit; 4. First thermal conductive layer; 5. Second thermal conductive layer. Detailed Implementation

[0039] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described and discussed below with reference to the accompanying drawings. Obviously, what is described here is only a part of the examples of this invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the protection scope of this invention.

[0040] To facilitate understanding of the embodiments of this utility model, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of this utility model.

[0041] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying 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 utility model.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0043] See Embodiment 1 of this utility model. Figures 1-7As shown, a dual-layer liquid-cooled battery pack is disclosed, including a liquid-cooled cover 1, a liquid-cooled base plate 2, a battery module 3, a first thermally conductive layer 4, and a second thermally conductive layer 5. The liquid-cooled cover 1 includes an integrally connected middle frame 11 and a liquid-cooled top plate 12. Preferably, the middle frame 11 and the liquid-cooled top plate 12 are laser-welded. The liquid-cooled cover 1 is assembled on the liquid-cooled base plate 2, and a battery space is formed between the liquid-cooled cover 1 and the liquid-cooled base plate 2. The battery module 3 is disposed in the battery space. The battery module 3 includes a CCS component 31 and a cell group 32 composed of several stacked cells. Multiple cell groups 32 can be provided and are linearly arranged with each other. The first thermally conductive layer 4 is disposed between the battery module 3 and the liquid-cooled top plate 12, and the second thermally conductive layer 5 is disposed between the battery module 3 and the liquid-cooled base plate 2. Preferably, the first thermally conductive layer 4 and the second thermally conductive layer 5 are thermally conductive adhesives. In this embodiment 1, the first thermally conductive layer 4 is block-shaped and used to contact the pads in the CCS module 31 with the liquid-cooled top plate 12. The second thermally conductive layer 5 is strip-shaped and used to contact the bottom surface of the battery cell with the liquid-cooled bottom plate 2. Preferably, the length direction of the second thermally conductive layer 5 is consistent with the battery cell stacking direction. Multiple second thermally conductive layers are linearly arranged along the stacking direction of the battery cells in the battery cell group 32, so that the second thermally conductive layer 5 can contact each battery cell stacked in the corresponding group, improving the heat dissipation uniformity of the battery cells. By setting the liquid-cooled top plate 12 and the liquid-cooled bottom plate 2 at the top and bottom of the battery module 3 respectively, the heat generated by the battery module 3 can be absorbed and carried away more effectively. The liquid-cooled top plate 12 and the middle frame 11 are integrated to form the liquid-cooled box cover 1, which improves the stability and reliability of the structure and eliminates the assembly process, thereby avoiding the problem of uneven torque during the assembly of the liquid-cooled bottom plate 2 in the traditional method.

[0044] In some embodiments, the liquid-cooled top plate 12 includes a top plate 121, a bottom plate 122, a surrounding plate 123, and fins 127. The bottom plate 122 is disposed opposite to the top plate 121. The surrounding plate 123 surrounds the edge between the top plate 121 and the bottom plate 122 to form a liquid-cooled tank 124 for containing coolant. The surrounding plate 123 is provided with a coolant inlet 125 and a coolant outlet 126 communicating with the liquid-cooled tank 124. The fins 127 are disposed within the liquid-cooled tank 124 to form a plurality of fins. The liquid cooling channels 128 flow from the coolant inlet 125 to the coolant outlet 126. The enclosure plate 123 not only seals the liquid cooling tank 124 but also provides the coolant inlet 125 and outlet 126, allowing the coolant to smoothly enter and exit the liquid cooling tank 124, forming a complete coolant circulation path. Fins 127 are installed within the liquid cooling tank 124, dividing it into multiple liquid cooling channels 128 flowing from the coolant inlet 125 to the coolant outlet 126, simplifying manufacturing. The fin design increases the contact area between the coolant and the liquid cooling top plate 12, improving heat transfer efficiency. Simultaneously, the multiple liquid cooling channels 128 allow for more even distribution of coolant within the liquid cooling tank 124, further enhancing heat dissipation performance.

[0045] Optionally, the fins 127 include, but are not limited to, straight fins 127, porous fins 127, serrated fins, and corrugated fins 127. Straight fins 127 can be classified into square, rectangular, triangular, trapezoidal, and other forms according to the flow channel. Their characteristic is that they have straight pathways, mainly serving to expand the heat transfer area and provide support, but have little effect on promoting fluid turbulence. Porous fins 127 have numerous small holes densely distributed on their fins. This structure can continuously disrupt the thermal resistance boundary layer, thereby improving heat transfer efficiency and making the fluid distribution in the fins 127 more uniform, which is beneficial for flushing impurity particles in the fluid. Serrated fins 127 are characterized by numerous tiny grooves along the length of the fin, forming several serrated pathways, which are beneficial for promoting fluid turbulence and disrupting the thermal resistance boundary layer, so that they can exhibit turbulent-like characteristics even in the low Reynolds number range.

[0046] In this embodiment 1, the fins 127 are rectangular with forward and reverse bends, and the liquid cooling channels 128 are U-shaped, with each channel 128 arranged in parallel. Because the U-shaped liquid cooling channels 128 are arranged in parallel, the coolant can be more evenly distributed within the liquid cooling tank 124. This uniform distribution avoids localized overheating or insufficient cooling, improves the uniformity and efficiency of heat dissipation, and solves the problem of excessive heat generation in the battery pack at high charge / discharge rates. Preferably, the fin material is 3-series aluminum alloy, which achieves a flow resistance of 2.4–2.8 kPa at a liquid cooling flow rate of 5 L / min and a liquid cooling temperature of 15–25°C, higher than the 3–5 kPa of other liquid cooling structures.

[0047] In some embodiments, to facilitate the injection and discharge of coolant, a first connecting plate 1231 and a second connecting plate 1232 extending outwardly at intervals are provided on one side of the enclosure 123. The coolant inlet 125 is located on the first connecting plate 1231, and the coolant outlet 126 is located on the second connecting plate 1232. A first mounting plate 1221 is provided on the bottom plate 122 corresponding to the first connecting plate 1231, and a second mounting plate 1222 is provided on the bottom plate 122 corresponding to the second connecting plate 1232. The top plate 121... A first cover plate 1211 is provided corresponding to the first connecting plate 1231, and a second cover plate 1212 is provided corresponding to the second connecting plate 1232. The first connecting plate 1231 and the second connecting plate 1232 provide installation positions for the coolant inlet 125 and the coolant outlet 126. The first mounting plate 1221 and the first cover plate 1211 clamp the first connecting plate 1231, and the second mounting plate 1222 and the second cover plate 1212 clamp the second connecting plate 1232, thereby improving the edge sealing of the coolant inlet 125 and the coolant outlet 126. In this embodiment 1, the first assembly plate 1221 is equipped with a liquid cooling inlet pipe 1223 facing the liquid cooling base plate 2. The liquid cooling inlet pipe 1223 is connected to the coolant inlet 125. The second assembly plate 1222 is equipped with a liquid cooling outlet pipe 1224 facing the liquid cooling base plate 2. The liquid cooling outlet pipe 1224 is connected to the coolant outlet 126. After the coolant enters the liquid cooling tank 124 from the liquid cooling inlet pipe 1223 through the coolant inlet 125, it flows along the liquid cooling channel 128 and absorbs heat. Then it flows through the coolant outlet 126 and out of the liquid cooling inlet pipe 1223 back to the coolant supply system for recooling. This circulation method improves heat dissipation efficiency and ensures the temperature stability of battery module 3 at high charge and discharge rates. The liquid cooling inlet pipe 1223 and the liquid cooling outlet pipe 1224 are both oriented towards the liquid cooling base plate 2. This design helps to reduce the height of the liquid cooling top plate 12 in the vertical direction, thereby improving the overall compactness of the battery pack. The liquid cooling inlet pipe 1223 and the liquid cooling outlet pipe 1224 are directly mounted on the assembly plate, simplifying the assembly process.

[0048] In one specific embodiment, to improve the manufacturing convenience of the middle frame 11, the middle frame 11 includes a first middle frame sidewall 111 and a thickened wall 112 distributed in a stepped manner. The thickened wall 112 is disposed on the side of the first middle frame sidewall 111 near the liquid-cooled top plate 12. The side of the thickened wall 112 facing the battery space is aligned with the side of the first middle frame sidewall 111 facing the battery space. The side of the thickened wall 112 facing out of the battery space protrudes from the side of the first middle frame sidewall 111 facing out of the battery space. The thickened wall 112 is welded to the liquid-cooled top plate 12, which enhances the strength and rigidity of the middle frame 11 in the connection area with the liquid-cooled top plate 12 and can effectively alleviate structural deformation. The thickened wall 112 can also increase the welding area with the liquid-cooled top plate 12, thereby improving welding stability and firmness. To improve the assembly stability between the first middle frame sidewall 111 and the liquid-cooled base plate 2, optionally, a first middle frame lip plate 113 is provided on the side of the first middle frame sidewall 111 closest to the liquid-cooled base plate 2, and is perpendicularly connected to the first middle frame sidewall 111. The first middle frame lip plate 113 is assembled and connected to the liquid-cooled base plate 2. Preferably, the first middle frame sidewall 111, the thickened wall 112, and the first middle frame lip plate 113 are integrally extruded. The included angle between the first middle frame sidewall 111 and the first middle frame lip plate 113 is 90°, which increases the contact area between the two, thereby increasing the sealing strength. The design of the first middle frame lip plate 113 enhances the overall structural strength of the middle frame 11, making the battery pack more stable and reliable when subjected to various external pressures. At the same time, it ensures that the liquid-cooled base plate 2 can be accurately installed on the middle frame 11, improving the connection sealing performance and ensuring the structural stability and heat dissipation performance of the entire battery pack. Preferably, the first middle frame sidewall 111, the thickened wall 112, and the first middle frame lip plate 113 are integrally extruded using an aluminum extrusion process, which requires an aluminum extrusion die. The thickened wall 112 can thicken the material at the top welding position and the bottom flange position, which can effectively alleviate structural deformation. By extruding aluminum alloy in a die under high temperature and high pressure to form parts with specific shapes and sizes, it has the advantages of high production efficiency, high material utilization, high part dimensional accuracy, and good surface quality. It reduces potential defects caused by welding, bolting, and other processes, and improves the structural strength and stability of the battery pack.

[0049] In another specific embodiment, the middle frame 11 includes an integrally bent second middle frame top wall 114 and a second middle frame side wall 115, the second middle frame top wall 114 being welded to the liquid-cooled top plate 12. An integrally bent second middle frame lip plate 116 is provided on the side of the second middle frame side wall 115 near the liquid-cooled bottom plate 2, and the second middle frame lip plate 116 is assembled and connected to the liquid-cooled bottom plate 2. The combination of integral bending and welding connection technologies can significantly improve the production efficiency of the battery pack. Integral bending reduces the processing steps and assembly time of parts, while welding simplifies the connection process and reduces production costs; the connection between the second middle frame lip plate 116 and the liquid-cooled bottom plate 2 is tighter and more reliable, reducing potential failures caused by loose connections or leaks, and improving the reliability and stability of the battery pack.

[0050] Optionally, the structure of the liquid-cooled base plate 2 can be the same as that of the liquid-cooled top plate 12. Of course, the liquid-cooled base plate 2 can also be a regular liquid-cooled plate. The liquid-cooled base plate 2 is also provided with an inlet 21 and an outlet 22. In some embodiments, the liquid-cooled base plate 2 and the liquid-cooled top plate 12 are connected to each other, so that the coolant can enter both the liquid-cooled base plate 2 and the liquid-cooled top plate 12 simultaneously during the injection process to dissipate heat from the battery module 3. In this embodiment 1, the liquid-cooled base plate 2 and the liquid-cooled top plate 12 are respectively connected to their own heat exchange systems, so the internal coolants are not connected.

[0051] A battery management system 33 and a socket unit 34 are also provided on one side of the middle frame 11. The battery management system 33 and the socket unit 34 are attached to one side of the middle frame 11 by screws. In this embodiment 1, the battery management system 33, the socket unit 34, the first connecting plate 1231 and the second connecting plate 1232 are all located on the same side.

[0052] After leaving the factory, the liquid cooling top plate 12 and the middle frame 11 in the liquid cooling box cover 1 are already integrated, so there is no need for additional assembly of the liquid cooling box cover 1. During assembly, the second heat-conducting layer 5 is arranged and applied on the liquid cooling bottom plate 2. Then, the stacked battery cell group 32 and CCS component 31 are combined, and the battery cell connecting aluminum busbar is welded to form the battery module 3. The battery module 3 is placed on the second heat-conducting layer 5. The battery management system 33 and socket unit 34 are installed on the battery module 3. Then, thermal conductive adhesive is applied to the CCS component 31 slot of the battery module 3. Finally, the liquid cooling box cover 1 is fastened to the top of the battery module 3. The first middle frame lip plate 113 or the second middle frame lip plate 116 is locked to the liquid cooling bottom plate 2 by bolts to complete the overall assembly of the battery pack.

[0053] In summary, the double-layer liquid-cooled battery pack provided by this utility model has the following technical effects:

[0054] 1. A dual-layer liquid cooling design, namely, a liquid cooling top plate 12 and a liquid cooling bottom plate 2 are respectively installed at the top and bottom of the battery module 3, which can more effectively absorb and remove the heat generated by the battery module 3 during charging and discharging. This design significantly improves heat dissipation efficiency, helps to reduce cell temperature, extend battery life, and improve the operating efficiency of the battery pack;

[0055] 2. The liquid-cooled top plate 12 and the middle frame 11 are integrated to form the liquid-cooled tank cover 1. This integrated design improves the stability and reliability of the structure. Compared with the traditional design where the liquid-cooled top plate 12 and the bottom plate are installed separately, this utility model avoids the complexity and potential errors in the assembly process, thereby improving the overall performance and safety of the battery pack.

[0056] 3. The assembly process between the liquid cooling tank cover 1 and the liquid cooling base plate 2 is simplified. Since the liquid cooling top plate 12 is already integrated with the middle frame 11, there is no need to install the liquid cooling top plate 12 separately. This reduces the number of assembly steps and required connectors, lowers manufacturing costs, and improves production efficiency.

[0057] 4. In traditional designs, the bottom liquid cooling plate is easily affected by the top liquid cooling plate and its fixing structure during installation, resulting in uneven application of bolt torque. This invention avoids this problem through the integrated design of the liquid cooling top plate 12 and the middle frame 11. The liquid cooling tank cover 1 is assembled as a single structure onto the liquid cooling bottom plate 2, ensuring uniform application of bolt torque, thereby improving the tight contact between the liquid cooling plate and the battery cell and the heat transfer efficiency.

[0058] The technical means disclosed in this utility model are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

Claims

1. A dual-layer liquid-cooled battery pack, characterized by, The application relates to a liquid-cooled battery box. The liquid-cooled battery box comprises: a liquid-cooled box cover (1) comprising an integral connection of a middle frame (11) and a liquid-cooled top plate (12); a liquid-cooled bottom plate (2) on which the liquid-cooled box cover (1) is assembled, and a battery space formed between the liquid-cooled box cover (1) and the liquid-cooled bottom plate (2); a battery module (3) arranged in the battery space; a first heat-conducting layer (4) arranged between the battery module (3) and the liquid-cooled top plate (12); 2. The dual-layer liquid-cooled battery pack of claim 1, wherein, a second heat-conducting layer (5) arranged between the battery module (3) and the liquid-cooled bottom plate (2). The liquid-cooled top plate (12) comprises: a top plate (121); a bottom plate (122) arranged opposite to the top plate (121); a surrounding plate (123) surrounding the edges between the top plate (121) and the bottom plate (122) to form a liquid-cooled groove (124) for containing cooling liquid, the surrounding plate (123) being provided with a cooling liquid inlet (125) and a cooling liquid outlet (126) in communication with the liquid-cooled groove (124); 3. The dual-layer liquid-cooled battery pack of claim 2, wherein, fins (127) arranged in the liquid-cooled groove (124) to form a plurality of liquid-cooled flow channels (128) from the cooling liquid inlet (125) to the cooling liquid outlet (126).

4. The dual-layer liquid-cooled battery pack of claim 2, wherein, The liquid-cooled flow channels (128) are in a U shape, and each of the liquid-cooled flow channels (128) is arranged in parallel.

5. The dual layer liquid-cooled battery pack of claim 4, wherein, One side of the surrounding plate (123) is provided with a first connecting plate (1231) and a second connecting plate (1232) extending outward at intervals, the cooling liquid inlet (125) is arranged on the first connecting plate (1231), the cooling liquid outlet (126) is arranged on the second connecting plate (1232), the bottom plate (122) is provided with a first assembly plate (1221) corresponding to the first connecting plate (1231), the bottom plate (122) is provided with a second assembly plate (1222) corresponding to the second connecting plate (1232), the top plate (121) is provided with a first cover plate (1211) corresponding to the first connecting plate (1231), and the top plate (121) is provided with a second cover plate (1212) corresponding to the second connecting plate (1232). The first assembly plate (1221) is assembled with a liquid-cooled inlet pipe (1223) directed towards the liquid-cooled bottom plate (2), the liquid-cooled inlet pipe (1223) being in communication with the cooling liquid inlet (125), and the second assembly plate (1222) is assembled with a liquid-cooled outlet pipe (1224) directed towards the liquid-cooled bottom plate (2), the liquid-cooled outlet pipe (1224) being in communication with the cooling liquid outlet (126).

6. The dual-layer liquid-cooled battery pack of claim 1, wherein, The middle frame (11) comprises first middle frame side walls (111) in a stepped distribution and thickened walls (112), the thickened walls (112) are arranged on one side of the first middle frame side walls (111) close to the liquid cooling top plate (12), the thickened walls (112) are aligned with one side of the first middle frame side walls (111) toward the battery space, the thickened walls (112) protrude from the first middle frame side walls (111) on the side away from the battery space, and the thickened walls (112) are welded with the liquid cooling top plate (12).

7. The dual-layer liquid-cooled battery pack of claim 6, wherein, The first middle frame side walls (111) are provided with first middle frame lip plates (113) connected perpendicularly to the first middle frame side walls (111) on one side close to the liquid cooling bottom plate (2), and the first middle frame lip plates (113) are assembled and connected with the liquid cooling bottom plate (2).

8. The dual-layer liquid-cooled battery pack of claim 7, wherein, The first middle frame side walls (111), the thickened walls (112) and the first middle frame lip plates (113) are integrally extruded and formed.

9. The dual layer liquid-cooled battery pack of claim 1, wherein, The middle frame (11) comprises second middle frame top walls (114) and second middle frame side walls (115) integrally bent and formed, the second middle frame top walls (114) are welded with the liquid cooling top plate (12).

10. The dual-layer liquid-cooled battery pack of claim 9, wherein, The second middle frame side walls (115) are provided with second middle frame lip plates (116) integrally bent and formed on one side close to the liquid cooling bottom plate (2), and the second middle frame lip plates (116) are assembled and connected with the liquid cooling bottom plate (2).

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