A liquid cooling circulating lithium battery heat dissipation structure

Abstract

The utility model discloses a kind of liquid cooling circulation's lithium battery heat dissipation structure, battery module, by multiple lithium battery units matrix arrangement composition;Bionic vein type runner, cover in battery module surface, the runner is constituted by main channel and branch channel, branch channel is tree bifurcation extension and adhere to each lithium battery unit side wall;Dual-mode circulation system, including temperature difference drive module, electric pump and heat exchange fin, the temperature difference drive module connects battery module, electric pump is connected with main channel by pipeline;Deformable heat-conducting silica gel layer, filled in the gap between battery module and bionic vein type runner;Partition temperature control unit, embedded inside battery module, real-time monitoring each lithium battery unit temperature and independently adjusting the flow of corresponding branch channel.Effectively solve the key problems, such as low efficiency, temperature control uneven and higher energy consumption, which exist in traditional lithium battery heat dissipation scheme, with multiple significant advantages.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically to a liquid-cooled circulating lithium battery heat dissipation structure. Background Technology

[0002] Lithium-ion batteries are widely used in new energy vehicles, energy storage power stations, and other fields due to their advantages such as high energy density and long cycle life. However, lithium-ion batteries generate heat continuously during charging and discharging, especially in matrix-arranged battery modules where localized heat accumulation is prone to occur. If heat dissipation is not timely, it can lead to battery capacity decay, shortened cycle life, and even the risk of thermal runaway. Therefore, an efficient heat dissipation structure is a core requirement for ensuring the safe and stable operation of lithium-ion batteries.

[0003] Among existing heat dissipation technologies, air cooling is inefficient and poorly adaptable, making it difficult to meet the heat dissipation requirements of high-power modules. While conventional liquid cooling is more efficient, it has many drawbacks: the flow channels are mostly parallel structures, leading to uneven flow distribution and insufficient heat dissipation for distant batteries; the thermal conductive layers are mostly made of rigid materials, which cannot adapt to the thermal expansion of the battery and are prone to forming gaps that affect heat conduction; the circulation system mostly relies on the continuous operation of electric pumps, resulting in high energy consumption; and temperature control is mostly module-level monitoring, which cannot achieve precise control of individual batteries. In addition, the limited heat exchange methods in some flow channels and the limited thermal conductivity of heat exchange fins further restrict the improvement of heat dissipation performance. Therefore, there is an urgent need for a highly efficient, precise, and energy-saving heat dissipation structure to solve the above problems. Utility Model Content

[0004] In order to overcome the shortcomings of existing technical solutions, this utility model provides a liquid-cooled circulating lithium battery heat dissipation structure, which can effectively solve the problems mentioned in the background art.

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

[0006] A liquid-cooled circulating lithium battery heat dissipation structure, comprising:

[0007] The battery module consists of multiple lithium battery cells arranged in a matrix.

[0008] A biomimetic leaf vein-like flow channel covers the surface of the battery module. This flow channel consists of a main channel and branch channels. The branch channels extend in a tree-like fork and fit the sidewall of each lithium battery cell.

[0009] The dual-mode circulation system includes a temperature difference drive module, an electric pump, and heat exchange plates. The temperature difference drive module is connected to the battery module, and the electric pump is connected to the main channel through a pipeline.

[0010] A deformable thermally conductive silicone layer is used to fill the gap between the battery module and the biomimetic leaf vein-like flow channel.

[0011] The zoned temperature control unit is embedded inside the battery module to monitor the temperature of each lithium battery cell in real time and independently adjust the flow rate of the corresponding branch channel.

[0012] As a further description of the above technical solution, the width of the branch channel of the biomimetic leaf vein-type flow channel gradually decreases from the main channel to the end, with a decreasing gradient of 0.5 mm / level, and the width of the end channel is 0.8-1.2 mm.

[0013] As a further description of the above technical solution, the temperature difference drive module includes a piezoelectric microvalve connected to the zoned temperature control unit, and the piezoelectric microvalve is connected to the electric pump.

[0014] As a further description of the above technical solution, the thickness of the deformable thermally conductive silicone layer is 2-3mm, and its shape is dynamically adjusted according to the thermal expansion of the battery during charging and discharging.

[0015] As a further description of the above technical solution, the partitioned temperature control unit includes a miniature temperature sensor, which is embedded in the gap between each lithium battery cell.

[0016] As a further description of the above technical solution, the inner wall of the branch channel is provided with a spiral guide rib, and the inclination angle of the spiral guide rib is 15°-20°.

[0017] As a further description of the above technical solution, the heat exchange plate is coated with a carbon nanotube coating, the thickness of which is 50-100μm.

[0018] As a further description of the above technical solution,

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] The liquid-cooled circulating lithium battery heat dissipation structure of this utility model has at least one of the following beneficial effects during use:

[0021] The biomimetic leaf vein-style flow channel employs a tree-like branching design, combined with a special internal structure, to achieve uniform distribution of the cooling medium while significantly enhancing the heat exchange effect between the medium and the flow channel wall, thus significantly improving the single-channel heat exchange efficiency. The deformable thermally conductive silicone layer dynamically adjusts its shape according to the thermal expansion and contraction during battery charging and discharging, always maintaining a tight fit with the battery module and flow channel, completely eliminating gap insulation issues and ensuring efficient heat transfer from the battery to the flow channel. The dual-mode circulation system intelligently switches operating modes based on battery temperature status. Under low-load conditions, it achieves energy-saving operation by leveraging temperature differences, while actively improving circulation efficiency under high loads, adapting to different operating conditions. The zoned temperature control unit effectively optimizes the temperature distribution within the module through precise temperature monitoring and independent flow regulation, improving battery consistency.

[0022] Among them, the carbon nanotube coated heat exchanger enhances heat exchange capacity and accelerates heat dissipation to the external environment. This comprehensively improves heat dissipation efficiency and temperature control accuracy, extends battery life, and balances energy saving and operational reliability, making it widely adaptable to various high-power lithium battery application scenarios. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a liquid-cooled circulating lithium battery heat dissipation structure according to the present invention.

[0024] Figure 2 This is a schematic diagram of the first side view of a liquid-cooled circulating lithium battery heat dissipation structure according to the present invention.

[0025] Figure 3 This is a schematic diagram of the second side of a liquid-cooled circulating lithium battery heat dissipation structure according to the present invention.

[0026] Figure 4 This is a perspective view of a liquid-cooled circulating lithium battery heat dissipation structure according to the present invention.

[0027] Numbering on the map:

[0028] 1. Battery module; 101. Bionic leaf vein flow channel; 102. Lithium battery unit; 103. Zoned temperature control unit; 2. Dual-mode circulation system; 201. Electric pump; 202. Piezoelectric microvalve; 203. Temperature difference drive module; 204. Heat exchange plate; 3. Deformable thermally conductive silicone layer; 301. Carbon nanotube coating; 302. Spiral guide ribs. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] like Figure 1-4 As shown, this utility model provides a liquid-cooled circulating lithium battery heat dissipation structure, including:

[0031] Battery module 1 is composed of multiple lithium battery cells 102 arranged in a matrix;

[0032] A biomimetic leaf vein-like flow channel 101 is covered on the surface of the battery module 1. The flow channel consists of a main channel and branch channels. The branch channels extend in a tree-like fork and fit the sidewall of each lithium battery cell 102.

[0033] The dual-mode circulation system 2 includes a temperature difference drive module 203, an electric pump 201 and a heat exchange plate 204. The temperature difference drive module 203 is connected to the battery module 1, and the electric pump 201 is connected to the main channel through a pipeline.

[0034] The cooling medium carrying heat circulates and exchanges heat through a biomimetic leaf-vein-shaped flow channel 101. The main channel of this flow channel is connected to the electric pump 201, while the branch channels extend in a tree-like branching pattern and closely adhere to the sidewall of each lithium battery cell 102, forming a two-stage "main-branch" heat exchange network. The branch channels adopt a progressively decreasing width design (decreasing gradient 0.5mm / stage, end width 0.8-1.2mm), combined with the spiral guide ribs 302 with an inner wall tilt angle of 15°-20°, which allows the cooling medium to form a spiral flow pattern during the flow process. This extends the residence time of the medium on the sidewall of each battery cell and enhances the turbulent heat exchange effect between the medium and the channel wall, thereby improving the heat exchange efficiency of a single channel.

[0035] The circulating power is provided by the dual-mode circulation system 2: When the zone temperature control unit 103 detects that the temperature of the battery module 1 is in a low range (small temperature difference), the piezoelectric microvalve 202 (the core component of the temperature difference drive module 203) connected to the zone temperature control unit 103 is activated, using the temperature difference between the battery heat and the environment to drive the circulation of the cooling medium, achieving energy-saving operation; when the temperature rises to a set threshold (insufficient temperature difference drive), the piezoelectric microvalve 202 is linked to the electric pump 201 to start, increasing the flow rate of the cooling medium through active power output, ensuring that the heat dissipation capacity matches the heat intensity. The cooling medium carrying heat finally flows through the heat exchange plate 204 coated with a 50-100μm carbon nanotube coating 301. The high thermal conductivity of the carbon nanotube coating 301 accelerates the transfer of heat from the medium to the heat exchange plate 204, and then the heat exchange plate 204 dissipates the heat to the external environment, completing a single heat dissipation cycle.

[0036] A deformable thermally conductive silicone layer 3 is filled in the gap between the battery module 1 and the biomimetic leaf vein-type flow channel 101.

[0037] The heat generated by the lithium battery cell 102 during operation is first transferred to the deformable thermally conductive silicone layer 3, which fills the space between the battery module 1 and the biomimetic leaf-vein-shaped flow channel 101. This silicone layer, 2-3 mm thick, possesses excellent thermal conductivity and dynamic deformation capability. During battery charging and discharging, it dynamically adjusts its shape according to the battery's thermal expansion / contraction, always maintaining a tight fit between the surface of the battery module 1 and the inner wall of the flow channel, completely filling the gap between them and preventing the formation of an air insulation layer. This significantly improves the heat transfer efficiency from the battery module 1 to the flow channel. Subsequently, the heat is transferred through the flow channel wall to the cooling medium inside the flow channel.

[0038] The zoned temperature control unit 103 is embedded inside the battery module 1 to monitor the temperature of each lithium battery cell 102 in real time and independently adjust the flow rate of the corresponding branch channel.

[0039] The partitioned temperature control unit 103 embedded inside the battery module 1 is the "sensing center" of the entire heat dissipation system. Its miniature temperature sensors are evenly distributed in the gaps between each lithium battery cell 102, enabling it to capture the temperature change data of each individual lithium battery cell 102 in real time. Since the sensors are in direct contact with the gaps between the battery cells, monitoring errors caused by temperature conduction delays can be avoided, ensuring that the true temperature state of each battery cell is obtained, and providing data support for subsequent precise temperature control.

[0040] The zoned temperature control unit 103 independently adjusts the flow rate of the branch channels in the corresponding zones based on the temperature data fed back by each micro temperature sensor: for battery cells with high temperatures, it increases the medium flow rate of the corresponding branch channel to enhance local heat exchange intensity; for areas with normal temperatures, it maintains the basic flow rate. This zoned precise control method avoids the problems of "overheating" or "underheating" caused by traditional overall heat dissipation, and achieves uniform temperature control of the battery module 1.

[0041] Furthermore, the width of the branch channels of the biomimetic leaf vein-type flow channel 101 decreases gradually from the main channel to the end, with a decreasing gradient of 0.5 mm / level, and the width of the end channel is 0.8-1.2 mm.

[0042] After the cooling medium is delivered to the main channel by the electric pump 201 or the temperature difference drive module 203, it needs to be distributed to each branch channel to cover all lithium battery cells 102. This distribution channel uses a "gradually decreasing" width design to make the cross-sectional area of ​​the main channel to each branch channel present a gradient change to adapt to the flow distribution: the main channel, as the total flow inlet, has the largest width to ensure the total flow supply; the width of the first-level branch channel is reduced by 0.5mm compared to the main channel, the width of the second-level branch is reduced by another 0.5mm compared to the first-level branch, and so on, until the width of the end channel stabilizes at 0.8-1.2mm.

[0043] This avoids uneven flow distribution of the cooling medium at branch nodes (such as excessive flow in the near branch and insufficient flow in the far branch), ensuring that each lithium battery cell 102 receives a sufficient and balanced supply of cooling medium to its corresponding end branch channel. Simultaneously, the width of the end channel is controlled within a narrow channel range of 0.8-1.2 mm, ensuring close contact with the sidewall of each individual lithium battery cell 102 while maintaining a certain flow velocity within the limited space, thus improving the heat exchange efficiency between the medium and the channel wall.

[0044] Furthermore, the temperature difference drive module 203 includes a piezoelectric microvalve 202 connected to the zone temperature control unit 103, and the piezoelectric microvalve 202 is connected to the electric pump 201.

[0045] As the core actuator of the temperature difference drive module 203, the piezoelectric microvalve 202's start / stop and opening degree are controlled in real time by the zone temperature control unit 103 based on temperature data. When the zone temperature control unit 103 detects that the temperature difference between the battery module 1 and the ambient temperature reaches a set threshold (usually 5-8℃), the energy generated by the temperature difference is sufficient to drive the cooling medium to flow. At this time, the zone temperature control unit 103 sends a signal to open the piezoelectric microvalve 202, using the potential energy of the temperature difference to drive the cooling medium to circulate in the flow channel, thereby achieving passive heat dissipation.

[0046] When the heat intensity of battery module 1 increases and the temperature difference is insufficient to maintain efficient cycling (such as in fast charging and high-load discharge scenarios), the partition temperature control unit 103 detects the continuous rise in temperature and immediately sends a signal to control the piezoelectric microvalve 202 to start the electric pump 201. The electric pump 201 provides active power to increase the flow rate and circulation efficiency of the cooling medium. At this time, the piezoelectric microvalve 202 adjusts its opening degree according to the temperature data to assist in controlling the flow rate. When the temperature drops below the temperature difference drive threshold, the electric pump 201 stops and the piezoelectric microvalve 202 returns to independent control.

[0047] Furthermore, the thickness of the deformable thermally conductive silicone layer 3 is 2-3 mm, and its shape is dynamically adjusted according to the thermal expansion of the battery during charging and discharging.

[0048] The deformable thermally conductive silicone layer 3 serves as a "heat conduction bridge" between the battery module 1 and the biomimetic leaf vein-like flow channel 101. Its 2-3mm thickness design ensures the shortest heat conduction path while reserving redundant space for deformation. During the charging and discharging process, lithium batteries undergo thermal expansion due to chemical reactions, with a volume change rate typically ranging from 1% to 3%. Traditional rigid thermally conductive materials (such as metal thermal pads) cannot adapt to this volume change and will form gaps with the battery or flow channel, resulting in the formation of an air insulation layer and significantly reducing thermal conductivity.

[0049] The deformable thermally conductive silicone layer 3 possesses excellent elastic deformation capability. When the battery expands thermally, the silicone layer is compressed and deformed, tightly filling the gap between the battery and the flow channel. When the battery cools and contracts, the silicone layer elastically rebounds, maintaining its adherence and ensuring that heat is efficiently conducted from the surface of the battery module 1 to the flow channel wall through the silicone layer. Simultaneously, the 2-3mm thickness has been optimized to avoid both insufficient thermal conductivity area due to excessive thinness and excessively long thermal conductivity paths due to excessive thickness.

[0050] Furthermore, the partition temperature control unit 103 includes a miniature temperature sensor, which is embedded in the gap between each lithium battery cell 102.

[0051] Precise temperature control by zone is achieved through point-to-point temperature monitoring. The miniature temperature sensor adopts an embedded design and is directly placed in the gap between each lithium battery cell 102, making close contact with the surface of the battery cell (contact distance is less than 0.5mm). It can capture the temperature change of a single battery cell in real time, avoiding the monitoring error caused by the thermal conduction delay of traditional surface-mounted sensors.

[0052] All the monitoring data from the miniature temperature sensors are transmitted in real time to the control chip of the zone temperature control unit 103. The control chip identifies battery cells with abnormal temperatures (such as cells with temperatures more than 3°C higher than the average temperature of the module) through data comparison and analysis, and immediately sends instructions to the branch channel flow regulation components (such as solenoid valves) in the corresponding area to increase the flow of cooling medium in that area and achieve local enhanced heat dissipation. For areas with normal temperatures, the basic flow is maintained to avoid energy waste.

[0053] Furthermore, the inner wall of the branch channel is provided with a spiral guide rib 302, and the inclination angle of the spiral guide rib 302 is 15°-20°.

[0054] The heat exchange effect is enhanced by optimizing the internal structure of the flow channel. The spiral guide rib 302 is arranged on the inner wall of the branch channel. The tilt angle of 15°-20° is optimized by fluid dynamics simulation. When the cooling medium flows through the branch channel, the guide rib will guide the medium, turning the laminar flow that originally flowed along the channel axis into a spiral turbulent flow.

[0055] In turbulent flow, the mixing of particles within the medium is more intense, the boundary layer thickness is reduced, and the resistance to heat transfer from the channel wall to the medium interior is significantly decreased. Simultaneously, the helical flow extends the residence path of the cooling medium within the channel (30%-40% longer than in laminar flow), increasing the heat exchange time between the medium and the channel wall, allowing the medium to more fully absorb the heat transferred from the battery. Furthermore, the helical guide ribs 302 enhance the structural strength of the flow channel, preventing deformation caused by medium pressure.

[0056] Furthermore, the heat exchange plate 204 is coated with a carbon nanotube coating 301, the thickness of which is 50-100 μm.

[0057] The heat dissipation performance is improved by coating it with carbon nanotubes 301. Carbon nanotubes have excellent thermal conductivity, and the coating thickness of 50-100μm is designed to ensure thermal conductivity while avoiding the problem of coating peeling off due to excessive thickness.

[0058] When the cooling medium carrying heat flows through the heat exchanger 204, the heat is first transferred through the substrate of the heat exchanger 204 to the carbon nanotube coating 301. The carbon nanotubes inside the coating form a dense heat-conducting network, quickly dispersing the heat to the coating surface. Simultaneously, the high surface roughness of the carbon nanotube coating 301 increases the contact area with air (40%-60% larger than a smooth metal surface), accelerating convective and radiative heat dissipation into the air. Furthermore, the carbon nanotube coating 301 possesses excellent corrosion resistance, protecting the substrate of the heat exchanger 204 from environmental corrosion.

[0059] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A liquid-cooled circulating lithium battery heat dissipation structure, characterized in that, include: The battery module consists of multiple lithium battery cells arranged in a matrix. A biomimetic leaf vein-like flow channel covers the surface of the battery module. This flow channel consists of a main channel and branch channels. The branch channels extend in a tree-like fork and fit the sidewall of each lithium battery cell. The dual-mode circulation system includes a temperature difference drive module, an electric pump, and heat exchange plates. The temperature difference drive module is connected to the battery module, and the electric pump is connected to the main channel through a pipeline. A deformable thermally conductive silicone layer is used to fill the gap between the battery module and the biomimetic leaf vein-like flow channel. The zoned temperature control unit is embedded inside the battery module to monitor the temperature of each lithium battery cell in real time and independently adjust the flow rate of the corresponding branch channel.

2. The liquid-cooled circulating lithium battery heat dissipation structure according to claim 1, characterized in that: The width of the branch channels in the biomimetic leaf vein-like flow channel gradually decreases from the main channel to the end, with a decreasing gradient of 0.5 mm / level, and the width of the end channel is 0.8-1.2 mm.

3. The liquid-cooled circulating lithium battery heat dissipation structure according to claim 1, characterized in that: The temperature difference drive module includes a piezoelectric microvalve connected to the zoned temperature control unit, and the piezoelectric microvalve is connected to an electric pump.

4. The liquid-cooled circulating lithium battery heat dissipation structure according to claim 1, characterized in that: The thickness of the deformable thermally conductive silicone layer is 2-3 mm, and its shape is dynamically adjusted according to the thermal expansion of the battery during charging and discharging.

5. The liquid-cooled circulating lithium battery heat dissipation structure according to claim 1, characterized in that: The partitioned temperature control unit includes a miniature temperature sensor embedded in the gap between each lithium battery cell.

6. The liquid-cooled circulating lithium battery heat dissipation structure according to claim 1, characterized in that: The inner wall of the branch channel is provided with a spiral guide rib, and the inclination angle of the spiral guide rib is 15°-20°.

7. The liquid-cooled circulating lithium battery heat dissipation structure according to claim 1, characterized in that: The heat exchange plate is coated with a carbon nanotube coating, the thickness of which is 50-100 μm.

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