A hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack

Abstract

This invention discloses a hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack, belonging to the field of lithium-ion power battery technology. The battery adopts an axially continuous hollow structure, with positive and negative terminals and an explosion-proof valve integrated at the top, simplifying welding and enabling directional pressure relief. The module is equipped with a direct liquid-cooled top cover and internal cooling channels. The support structure is an integrated design, with built-in cooling rods and double-layer channels for simultaneous direct cooling of the cell's interior and exterior. The battery pack uses upper and lower cooling supports as its main body, with the channels also serving as structural reinforcement ribs. An explosion-proof gap is reserved at the top, and a dedicated exhaust channel is provided. This invention achieves efficient heat dissipation of the cell in all directions, meeting the requirements of high-power fast charging, improving structural strength and thermal safety performance, simplifying assembly processes, and increasing system energy density and production efficiency. It is suitable for power battery systems in new energy vehicles.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion power battery technology, specifically relating to a hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack. Background Technology

[0002] This invention belongs to the field of lithium-ion power battery technology, specifically relating to a hollow cylindrical battery cell, a cylindrical battery module with a direct liquid cooling structure, an integrated cooling bracket, and a fully cooled battery pack.

[0003] Traditional batteries have their positive and negative terminals and explosion-proof valves scattered, mostly located at the top and sides / bottom of the battery. The welding process is complex, the space utilization is low, and the pressure relief direction of the explosion-proof valves is inconsistent, which can easily lead to thermal runaway and explosion risks.

[0004] Conventional cylindrical batteries have a solid structure and can only dissipate heat through external liquid cooling plates. This results in a long cooling path and low heat exchange efficiency, which cannot meet the requirements of high-power fast charging.

[0005] Existing battery module brackets only serve to fix and insulate, have low structural strength, separate cooling channels from structural components, and have many parts, low integration, and limited energy density.

[0006] Traditional battery packs suffer from poor thermal runaway venting, lack dedicated explosion venting channels and structural reinforcement designs, and have insufficient impact resistance and safety protection capabilities.

[0007] To address the shortcomings of existing technologies, this invention provides a hollow cylindrical battery with top-integrated terminals and an explosion-proof valve, a direct liquid cooling module, an integrated structure-cooling bracket, and a fully cooled battery pack, achieving dual internal and external cooling, structural enhancement, rapid pressure relief, efficient welding, and high integration, thereby improving fast charging performance and safety levels. Summary of the Invention

[0008] In view of this, the present invention provides a hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack to solve or alleviate one of the technical problems existing in the prior art, and at least provides a beneficial alternative.

[0009] The technical solution of this invention is implemented as follows: a hollow cylindrical battery and direct liquid cooling, including a hollow cylindrical battery cell and a battery body, wherein a through-type hollow channel is arranged axially inside the battery body; positive and negative terminals and an explosion-proof valve are integrated on the top of the battery body, the positive and negative terminals are located at the top center, and the explosion-proof valve is symmetrically arranged on both sides of the positive and negative terminals, and both the positive and negative terminals and the explosion-proof valve face upwards from the top of the battery.

[0010] Furthermore, the positive and negative terminals are circular, the explosion-proof valve has a square-round structure, and there are two explosion-proof valves symmetrically distributed.

[0011] It includes a direct liquid cooling module cover; the direct liquid cooling module cover has an integrally formed cooling channel inside, which is evenly distributed along the plane of the cover and is used to directly cool the top of the battery, the busbar and the FPC integrated board.

[0012] The cooling channels inside the top cover of the direct liquid cooling module are arranged in a parallel or serpentine pattern, and the top cover of the direct liquid cooling module is provided with an interface.

[0013] The invention includes an integrated cooling bracket with battery mounting holes and cooling channels inside the bracket, the channel walls of which also serve as structural reinforcing ribs; each battery mounting hole contains an integrally formed cooling rod that extends upward into the hollow channel of a hollow cylindrical battery cell.

[0014] The integrated cooling bracket includes a lower cooling bracket, which has two independent cooling channels inside: an upper cooling channel and a lower cooling channel. The upper cooling channel is connected to the cooling rod and is used to cool the inside of the battery cell. The lower cooling channel surrounds the lower middle and bottom of the battery and is used to cool the outside of the battery cell.

[0015] The internal flow channel of the cooling rod is a double spiral rising and falling flow direction, and the cooling rod and the lower cooling bracket are integrally formed.

[0016] It includes a fully cooled battery pack; the fully cooled battery pack has an upper liquid cooling bracket and a lower cooling bracket as the main load-bearing structure, an explosion venting gap is reserved at the top of the battery pack, and a dedicated exhaust channel is set on the outside.

[0017] The fully cooled battery pack also includes a busbar and an integrated FPC board, and a hollow cylindrical battery pack; the internal flow channels of the upper liquid cooling bracket and the lower cooling bracket also serve as structural reinforcing ribs, improving the battery pack's resistance to impact, vibration, and compression.

[0018] In the event of thermal runaway, the explosion-proof valve of the hollow cylindrical battery cell releases pressure upwards. The high-temperature and high-pressure gas is collected through the explosion-proof gap and then quickly discharged outside the battery through a dedicated exhaust channel, thus preventing the spread of thermal runaway.

[0019] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions: 1) Achieves direct cooling on both the inner and outer sides of the battery cell, significantly improving cooling efficiency. 2) The integrated structure and cooling system significantly improve the overall strength and reliability of the battery pack. 3) The explosion-proof pressure relief path is optimal, and the thermal safety protection capability is significantly enhanced. 4) The pole is integrated with the top of the explosion-proof valve, greatly simplifying the welding process. 5) The cooling channel layout is uniform, resulting in better cell temperature consistency. 6) High integration of components, resulting in increased system energy density 7) The busbar is directly cooled to the FPC, resulting in a more stable electrical connection. 8) The assembly process is simplified, making it suitable for automated mass production. 9) The exhaust channel is independent, preventing contamination of the cooling circuit and electrical components. Simulation results demonstrate that the hollow structure, cooling rod, double-layer flow channel, and direct cooling top cover of this invention increase the battery heat exchange area by over 180%, reduce cell temperature rise by over 50% under fast charging conditions, and achieve a module temperature difference of ≤5℃. The upward-facing explosion-proof valve and top exhaust channel shorten the pressure relief time to less than 18ms, allowing thermal runaway gas to escape from the battery pack within 100ms, effectively suppressing heat propagation. The flow channel also functions as a reinforcing rib, increasing structural rigidity by over 120%. The integrated top electrode post improves welding efficiency by 40% and reduces the defect rate by 70%.

[0020] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the hollow cylindrical battery cell structure of the present invention; Figure 2 This is a schematic diagram of the top structure of the hollow cylindrical battery cell in this invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the hollow cylindrical battery cell of the present invention; Figure 4 This is a schematic diagram of the upper cover structure of the direct liquid cooling module of the present invention; Figure 5 This is a schematic diagram of the flow channel and interface of the upper cover of the direct liquid cooling module of the present invention; Figure 6 This is a schematic diagram of the integrated cooling bracket structure of the present invention; Figure 7 This is a schematic diagram of the layered flow channels of the integrated cooling bracket of the present invention; Figure 8 This is a schematic diagram of the cylindrical battery module assembly of the present invention; Figure 9 This is a schematic diagram of the overall structure of the fully cooled battery pack of the present invention; Figure 10 This is a schematic cross-sectional view of the fully cooled battery pack of the present invention. Detailed Implementation

[0023] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0024] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0025] Hollow cylindrical battery cell This invention provides a hollow cylindrical battery 100. The battery is cylindrical in shape, with a through-hole hollow channel 102 arranged axially inside the cell to form a hollow structure. Positive and negative terminals 103 and explosion-proof valves 104 are integrated at the top of the battery. The positive and negative terminals 103 are circular and located at the top center. The two explosion-proof valves 104 are square-round in structure and symmetrically arranged on both sides of the circular terminals 103. Both the positive and negative terminals 103 and the explosion-proof valves 104 face upwards from the top of the battery, concentrating the welding positions and ensuring the explosion-proof pressure relief direction is consistently upwards, facilitating assembly and improving safety performance. The hollow channel 102 works in conjunction with a cooling rod 302 to achieve internal cooling of the cell. Combined with an external cooling structure, this forms double-sided cooling, significantly improving heat dissipation efficiency and meeting the requirements of high-power fast charging.

[0026] Top cover of direct liquid cooling module The present invention also includes a direct liquid cooling module cover 200, which covers the top of the cylindrical battery module. The cover has an integrally formed cooling channel 201 inside, which is evenly distributed along the plane of the cover. The cooling channel is used to introduce coolant, directly cooling the top of the battery, the busbar, and the FPC integrated board 500, reducing the temperature rise of high-current connection parts, decreasing contact resistance, and improving electrical connection reliability and battery operating consistency.

[0027] Cylindrical battery module bracket This invention provides a module bracket 300 integrating structure and cooling, comprising an upper bracket, a lower cooling bracket 305, and battery mounting holes 301. The bracket's interior is densely packed with cooling channels, the channel walls of which also serve as structural reinforcing ribs, improving the overall strength and impact resistance of the bracket. Each battery mounting hole 301 contains a cooling rod 302, which is integrally formed with the lower cooling bracket 305. The cooling rod 302 extends upwards into the hollow channel 102 of the battery, achieving direct cooling of the battery cell's interior. The flow channels within the cooling rod exhibit a double-helix upward and downward flow direction, achieving the cooling effect. The lower cooling bracket 305 has two independent cooling channels: the upper cooling channel 303 communicates with the cooling rod 302 and is used to cool the battery's interior; the lower cooling channel 304 surrounds the lower and bottom parts of the battery and is used to cool the battery's exterior. The two channels are independently sealed and do not interfere with each other, achieving all-round cooling of the lower, bottom, and interior parts of the battery.

[0028] Overall structure of fully cooled battery pack This invention also provides a fully cooled cylindrical battery pack 400. The battery pack has an integrated cooling support as its main structure, and is primarily composed of an upper liquid cooling support 401, a busbar and FPC integrated plate 402, a hollow cylindrical battery pack 403, and a lower cooling support 405 assembled sequentially. The upper liquid cooling support 401 and the lower cooling support 405 together form the battery pack's load-bearing frame. The internal flow channels serve both cooling and structural reinforcement functions, improving the overall rigidity, vibration resistance, and compression resistance of the battery pack. A pre-reserved explosion-proof gap 404 is provided between the top of the battery pack and the upper liquid cooling support 401, and a dedicated exhaust channel 405 is provided on the outside of the battery pack. When thermal runaway occurs, the high-temperature, high-pressure gas ejected upwards by the explosion-proof valve 104 is collected through the explosion-proof gap 404 and quickly discharged outside the pack through the exhaust channel, effectively suppressing heat spread and improving the battery pack's safety level.

[0029] Hollow cylindrical battery Combination Figure 1 , Figure 2 , Figure 3This embodiment provides a hollow cylindrical battery 100, which includes a battery body 101, a hollow channel 102, circular positive and negative terminals 103, and square-shaped explosion-proof valves 104. The battery body 101 has a cylindrical wound structure or a stacked structure. A through-type hollow channel 102 is axially formed at the center of the battery body 101. The hollow channel 102 is used to cooperate with a cooling rod 302 to achieve direct cooling of the battery interior. The circular positive and negative terminals 103 and two square-shaped explosion-proof valves 104 are integrated on the top of the battery body 101. The circular positive and negative terminals 103 are centrally located, and the two square-shaped explosion-proof valves 104 are symmetrically arranged on both sides of the circular positive and negative terminals 103, with both the circular positive and negative terminals 103 and the square-shaped explosion-proof valves 104 facing upwards. The above structure allows for centralized welding stations and simplified assembly processes. At the same time, the explosion-proof valve can quickly release pressure upwards, effectively preventing internal pressure buildup during thermal runaway and improving battery safety.

[0030] Top cover of direct liquid cooling module Combination Figure 4 , Figure 5 This embodiment provides a direct liquid cooling module cover 200, with cooling channels 201 formed inside the cover. The channels are arranged in a uniformly distributed parallel / serpentine layout. Coolant flows in from the cover interface, passes over the top of the battery, the busbar, and the FPC integrated board 500, directly carrying away heat from the electrical connection parts, reducing the temperature rise during high-current operation, and improving connection reliability and lifespan.

[0031] Cylindrical battery module bracket Combination Figure 6 , Figure 7 , Figure 8 This embodiment provides a cylindrical battery module bracket 300, including battery mounting holes 301, cooling rods 302, upper cooling channels 303, lower cooling channels 304, and a lower cooling bracket 305. The bracket is integrally molded from high-strength thermally conductive material, replacing traditional plastic / sheet metal brackets. Each battery mounting hole 301 contains a cooling rod 302, which is inserted into a hollow channel 102. The flow channels within the cooling rods exhibit a double-spiral upward and downward flow direction, achieving a cooling effect. The lower cooling bracket 305 has two internal flow channels: the upper cooling channel 303 supplies liquid to the cooling rods 302, achieving internal cooling of the battery cell; the lower cooling channel 304 surrounds the lower middle and bottom of the battery, achieving external cooling. The flow channels also serve as structural reinforcing ribs, improving the overall rigidity and impact resistance of the bracket.

[0032] Fully Cooled Battery Pack Combination Figure 9 , Figure 10This embodiment provides a fully cooled cylindrical battery pack 400, which is assembled sequentially from an upper liquid cooling bracket 401, a busbar and FPC integrated board 500, a hollow cylindrical battery pack 403, and a lower cooling bracket 305. The upper liquid cooling bracket 401 and the lower cooling bracket 405 together form the main frame of the battery pack, and the internal flow channels also serve as structural reinforcing ribs 406, improving the pack's impact and vibration resistance. An explosion-proof gap 404 is reserved at the top of the battery pack, and an exhaust channel is provided. The high-temperature and high-pressure gas discharged upward by the explosion-proof valve is quickly discharged outside the pack through the explosion-proof gap and the exhaust channel, preventing the spread of thermal runaway and improving the overall safety level.

[0033] Working principle The hollow cylindrical battery 100 has a centrally located hollow channel 102, into which a cooling rod 302 is inserted to directly absorb heat from the center of the cell. The lower cooling bracket 305 has a double-layer flow channel that cools the internal and external surfaces of the battery, respectively. The upper liquid cooling bracket 401 directly dissipates heat from the top of the battery, the busbar, and the integrated FPC board 500. Internal central cooling, external surface cooling, and top connection cooling form a three-dimensional, all-around direct cooling system, which significantly reduces thermal resistance, improves heat dissipation speed, and meets the requirements of high-rate fast charging.

[0034] The positive and negative terminals 103 and the explosion-proof valve 104 are all centrally arranged on the top of the battery. The welding points are uniform and in the same direction, resulting in a short current conduction path, which reduces connection heat generation, improves welding efficiency, saves top space, and improves space utilization.

[0035] When the internal pressure of the battery rises abnormally, the top explosion-proof valve 104 opens upward, and the high-pressure gas enters the explosion-proof gap 404 directly along the shortest path, and then is discharged outward through the exhaust channel; the gas does not spread laterally or impact adjacent cells, and the pressure is reduced quickly and the heat spread is blocked.

[0036] The internal flow channel walls of the module bracket 300 and the lower cooling bracket 305 serve as structural reinforcing ribs. While bearing the function of coolant flow, they enhance the bracket's resistance to bending, compression, and vibration, achieving the integration of structural load-bearing and liquid cooling heat dissipation, reducing the number of parts, and improving energy density and reliability.

[0037] The battery pack uses upper and lower liquid-cooled brackets as its main load-bearing structure, with the cooling system dissipating heat during fast charging and discharging. The electrical system enables power input and output, and the safety system provides rapid venting and explosion prevention in the event of thermal runaway. These three components work together to ensure stable operation of the battery pack under high power, high safety, and long lifespan conditions.

[0038] Data supporting the technical effects achieved by the technical solution Achieving direct cooling on both the inner and outer sides of the battery cell significantly improves cooling efficiency. Hollow cells, combined with internal cooling rods, a double-layer flow channel in the support frame, and a direct cooling flow channel on the top cover, form all-round cooling. The heat dissipation capacity is significantly better than that of traditional single-sided external cooling structures, which can meet the requirements of high-power fast charging and effectively reduce the risk of temperature rise and thermal runaway.

[0039] The explosion-proof pressure relief path is optimized, and the thermal safety protection capability is significantly enhanced. With the explosion-proof valve facing upwards, combined with the explosion-proof gap at the top of the battery pack and a dedicated exhaust channel, high-temperature and high-pressure gases can be quickly discharged upwards, preventing accumulation and spread, and significantly reducing the risk of explosion and thermal runaway.

[0040] The integrated structure and cooling system significantly improve the overall strength and reliability of the battery pack. The cooling channels also serve as structural reinforcements, replacing traditional simple supports. This significantly improves the overall impact resistance, vibration resistance, and compression resistance, while reducing the number of structural components and enhancing system reliability.

[0041] The electrode post is integrated with the top of the explosion-proof valve, greatly simplifying the welding process. With both positive and negative terminals located at the top, the welding positions are concentrated and the path is short, which facilitates automated welding, improves production efficiency and welding yield, and saves top space, thus improving space utilization.

[0042] The uniform cooling channel layout results in better cell temperature consistency. Simultaneous cooling of the top cover, middle, bottom, and interior results in a smaller temperature difference across the entire pack, improving battery cycle life and SOC consistency.

[0043] Highly integrated components increase system energy density The system integrates support, cooling, and structural functions, reducing redundant components and allowing more cells to be accommodated in the same volume, thereby increasing the energy density at the pack level.

[0044] The busbar is directly cooled by the FPC, resulting in a more stable electrical connection. The top cover channel directly cools the connection parts, reducing heat generation from high current, minimizing the risk of increased contact resistance, and improving the reliability of electrical connections.

[0045] The assembly process is simplified, making it suitable for automated mass production. The upper and lower supports are integrated, and the cooling rod is molded as a single piece, resulting in fewer assembly steps, high positioning accuracy, and compatibility with large-scale automated production lines.

[0046] Independent exhaust channels prevent contamination of cooling circuits and electrical components. The explosion disposal path is isolated from the cooling and electrical systems, preventing high-temperature flue gas from entering the flow channel, thus avoiding corrosion and short circuits and improving long-term safety.

[0047] Simulation results demonstrate that the hollow structure, cooling rod, double-layer flow channel, and direct cooling top cover of this invention increase the battery heat exchange area by over 180%, reduce cell temperature rise by over 50% under fast charging conditions, and achieve a module temperature difference of ≤5℃. The upward-facing explosion-proof valve and top exhaust channel shorten the pressure relief time to less than 18ms, allowing thermal runaway gases to exit the battery pack within 100ms, effectively suppressing heat propagation. The flow channel also functions as a reinforcing rib, increasing structural rigidity by over 120%. The integrated top electrode increases welding efficiency by 40% and reduces the defect rate by 70%. These data fully demonstrate that the technical solution of this invention significantly improves cooling efficiency, safety performance, structural strength, and manufacturability, possessing outstanding substantive features and significant advancements.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack, characterized in that: The battery includes a hollow cylindrical battery cell (100) and a battery body (101). The battery body (101) has an axially arranged through-hole hollow channel (102). Positive and negative terminals (103) and an explosion-proof valve (104) are integrated on the top of the battery body (101). The positive and negative terminals (103) are located at the top center, and the explosion-proof valve (104) is symmetrically arranged on both sides of the positive and negative terminals (103). Both the positive and negative terminals (103) and the explosion-proof valve (104) face the top of the battery.

2. The hollow cylindrical battery and the integrated direct liquid cooling battery pack according to claim 1, characterized in that: The positive and negative terminals (103) are circular terminals, and the explosion-proof valve (104) has a square-round structure. There are two explosion-proof valves (104) and they are symmetrically distributed.

3. A hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack according to any one of claims 1-2, characterized in that: Includes a direct liquid cooling module cover (200); the direct liquid cooling module cover (200) has an integrally formed cover cooling channel (201) inside, the cover cooling channel (201) is evenly distributed along the cover plane, and is used to directly cool the top of the battery, the busbar and the FPC integrated plate (500).

4. The hollow cylindrical battery and the integrated direct liquid cooling battery pack according to claim 3, characterized in that: The cooling channels (201) inside the top cover (200) of the direct liquid cooling module are arranged in a parallel or serpentine layout, and the top cover (200) of the direct liquid cooling module is provided with an interface (105).

5. A hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack according to any one of claims 3-4, characterized in that: The device includes an integrated cooling bracket (300), which has battery mounting holes (301) and cooling channels inside the bracket. The channel walls also serve as structural reinforcing ribs. Each battery mounting hole (301) contains an integrally formed cooling rod (302), which extends upward into the hollow channel (102) of the hollow cylindrical battery cell (100).

6. The hollow cylindrical battery and direct liquid-cooled integrated cooling battery pack according to claim 5, characterized in that, The integrated cooling bracket (300) includes a lower cooling bracket (305), which has two independent cooling channels inside: an upper cooling channel (303) and a lower cooling channel (304). The upper cooling channel (303) is connected to the cooling rod (302) and is used to cool the inside of the battery cell. The lower cooling channel (304) wraps around the lower middle and bottom of the battery cell and is used to cool the outside of the battery cell.

7. A hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack according to claim 6, characterized in that: The internal flow channel of the cooling rod (302) is a double spiral upward and downward flow direction, and the cooling rod (302) and the lower cooling bracket (305) are integrally formed.

8. A hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack according to any one of claims 1-7, characterized in that: It includes a fully cooled battery pack (400); the fully cooled battery pack (400) has an upper liquid cooling bracket (401) and a lower cooling bracket (405) as the main load-bearing structure, a pre-reserved explosion venting gap (404) at the upper part of the battery pack, and a dedicated exhaust channel (405) on the outside.

9. A hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack according to claim 8, characterized in that: The fully cooled battery pack (400) also includes a busbar and an integrated FPC board (402) and a hollow cylindrical battery pack (403); the internal flow channels of the upper liquid cooling bracket (401) and the lower cooling bracket (405) also serve as structural reinforcing ribs (406), improving the battery pack's impact resistance, vibration resistance, and compression resistance.

10. A hollow cylindrical battery and a direct liquid-cooled integrated cooling battery pack according to claim 8, characterized in that: In the event of thermal runaway, the explosion-proof valve (104) of the hollow cylindrical battery cell (100) releases pressure upwards, and the high-temperature and high-pressure gas is collected through the explosion-proof gap (404) and then quickly discharged outside the package through the dedicated exhaust channel (405), thus blocking the spread of thermal runaway.

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