High-efficiency heat dissipation bus

Abstract

The application discloses a high-efficiency heat-dissipation bus, and belongs to the technical field of buses.The high-efficiency heat-dissipation bus comprises a copper-clad aluminum pipe layer, a shielding layer and an insulating layer, the heat-dissipation effect is realized by modifying the insulating layer, and the insulating layer comprises, in weight parts, 100-200 parts of silicone rubber, 20-30 parts of fumed white carbon black, 20-30 parts of boron nitride, 10-25 parts of four-needle-shaped zinc oxide whiskers, 15-30 parts of an interfacial agent and 1-5 parts of a silane coupling agent; wherein the interfacial agent is acryloyl perylene and N-acryloyl piperidine modified polysiloxane.The composite filler of sheet boron nitride and four-needle-shaped zinc oxide whiskers is blended with the interfacial agent, three-dimensional heat-conducting channels can be formed in the silicone rubber substrate, the interfacial thermal resistance is reduced, the interfacial structure is optimized, the heat-conducting performance and heat-resistant performance of the insulating layer material are greatly improved, and the mechanical performance and insulating performance are not negatively affected.

Description

Technical Field

[0001] This invention relates to the field of busbar technology, specifically to a high-efficiency heat dissipation busbar. Background Technology

[0002] Busbars are a crucial component of power plants and substations, connecting generators, transformers, transmission lines, distribution lines, and phase-regulating equipment. The reliability of busbar operation directly impacts the overall reliability of the power plant and substation. Therefore, busbar design is a vital aspect of ensuring the safe operation of the power system, especially the heat dissipation performance of the busbar insulation layer, which is critical for the safe and efficient operation of the power system. This is because busbars generate heat due to resistive losses during current transmission. When the insulation layer has poor heat dissipation, heat accumulation leads to localized temperature increases. When the temperature exceeds the insulation material's tolerance threshold, it accelerates insulation aging and carbonization, and may even cause breakdown and short circuits, resulting in power outages or fire risks. Furthermore, high temperatures reduce the dielectric strength of the insulation material, exacerbating partial discharge. Simultaneously, conductor resistance increases with temperature; poor insulation heat dissipation further increases busbar temperature and resistance, exacerbating transmission losses and creating a vicious cycle of "heat generation-loss-heat generation." Therefore, busbars with good heat dissipation performance can control the busbar temperature within a reasonable range, ensuring transmission efficiency, maintaining the dielectric stability of the insulation layer, and reducing discharge damage.

[0003] Silicone rubber has attracted much attention in busbar insulation layers due to its excellent insulation properties, lightweight, and low cost. However, pure silicone rubber has a low thermal conductivity and often needs to be mixed with thermally conductive fillers to improve the thermal conductivity of the composite material. Boron nitride, with its layered structure, excellent thermal conductivity, high thermal stability, low coefficient of thermal expansion, and high insulation properties, is highly valuable for use in extreme environments such as high temperature and high pressure. By introducing boron nitride, a phonon transfer channel is provided in the polymer matrix, allowing heat to dissipate rapidly through the heat transfer channel, avoiding large amounts of heat accumulation and extending the service life of the busbar insulation layer. Boron nitride also has extremely low dielectric loss and good insulation performance, but its dispersion properties are poor, and it is prone to agglomeration. The thermal conductivity of the composite material is positively correlated with the filler content. At low filler content, the polymer is a continuous phase, while the filler is an isolated dispersed phase, distributed in a "sea-island" pattern within the composite material, resulting in a minimal improvement in thermal conductivity. As the filler content increases, the contact between the filler and the polymer gradually tightens. Once the percolation threshold for forming thermally conductive pathways and networks is reached, the thermal conductivity of the composite material significantly improves. However, due to the differences in properties between the inorganic filler and the organic polymer matrix, their compatibility is relatively poor. This not only creates thermal resistance at the filler-matrix interface, leading to severe phonon scattering at the interface, but also affects the dispersibility of the filler in the matrix, thereby reducing the thermal conductivity of the composite material. Therefore, it is still necessary to modify the filler or composite material to enhance the interfacial coupling between the filler and the polymer, reduce defects, improve the adhesion between the filler and the matrix, and reduce phonon scattering at the interface. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, the present invention provides a high-efficiency heat dissipation busbar, whose heat dissipation effect is achieved by modifying the insulation layer material. By adding acryloylperylene and N-acryloylpiperidine modified polysiloxane as an interface agent to the silicone rubber and thermally conductive filler composite material of the insulation layer, the interfacial coupling between the filler and the polymer is greatly enhanced, the adhesion between the filler and the matrix is ​​improved, and the thermal conductivity of the insulation layer is improved through the "hydrogen bond-phonon" synergistic heat conduction path.

[0005] The technical solution for achieving the objective of this invention is as follows:

[0006] A high-efficiency heat dissipation busbar includes a copper-clad aluminum tube layer, a shielding layer, and an insulating layer. The insulating layer, by weight, comprises 100-200 parts silicone rubber, 20-30 parts fumed silica, 20-30 parts boron nitride, 10-25 parts tetragonal zinc oxide whiskers, 15-30 parts interface agent, and 1-5 parts silane coupling agent. The interface agent has the general structural formula shown in Formula 1.

[0007]

[0008] Equation 1, where m is 2 to 4, n is 10 to 20, and a is 5 to 15.

[0009] Among them, lamellar boron nitride has a high in-plane thermal conductivity, which can form a two-dimensional thermal conductive path in the silicone rubber matrix, but its out-of-plane thermal conductivity is poor. The tetraneedle zinc oxide whiskers are distributed in a three-dimensional skeleton morphology. Their needle-like structure can penetrate the gaps between boron nitride lamellars, acting as thermal bridges to connect adjacent boron nitride lamellars, forming a two-dimensional lamellar-three-dimensional bridging interconnect network, reducing interfacial thermal resistance. At the same time, the three-dimensional structure of the tetraneedle zinc oxide whiskers avoids the stacking and agglomeration of boron nitride lamellars, resulting in a highly dense network with low porosity and improved phonon transport efficiency.

[0010] Preferably, the mass ratio of boron nitride to tetraneedle zinc oxide whiskers is 1:1.

[0011] The interface agent is obtained by modifying polysiloxane with acryloylperylene and N-acryloylpiperidine. Polysiloxane has good compatibility with silicone rubber, and the perylene group on the polysiloxane chain has conjugated π electrons, which can form π-π stacking between boron nitride layers, improving the dispersibility of boron nitride and the interfacial compatibility with the silicone rubber substrate. The amide carbonyl group of N-acryloylpiperidine can act as a hydrogen bond acceptor, forming a hydrogen bond network with the hydroxyl groups on the surface of boron nitride, tetraneedle zinc oxide whiskers, and fumed silica, thereby reducing phonon scattering, avoiding the formation of thermally resistant interfaces, and further improving the thermal conductivity of the composite material.

[0012] In one specific embodiment, the shielding layer is any one of a copper foil shielding layer, a copper wire braided shielding layer, an aluminum foil shielding layer, and an aluminum wire braided shielding layer.

[0013] In one specific embodiment, the preparation method of the interface agent is as follows:

[0014] S1. Octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane and an initiator are added to a reactor and stirred under N2 atmosphere and room temperature. After the reaction is completed, excess anhydrous sodium bicarbonate and excess anhydrous sodium sulfate are added. Then, the mixture is filtered, rotary evaporated and vacuum dried to obtain hydrogen-containing polysiloxane.

[0015] S2. Acryloylperylene, N-acryloylpiperidine, caster catalyst and toluene are added sequentially to the reactor. The mixture is stirred under N2 atmosphere and heated to 70-90°C. The hydrogen-containing polysiloxane is dissolved in toluene and then added dropwise to the reactor using a constant pressure dropping funnel. The mixture is heated to 100-120°C and the reaction is continued for 18-24 hours. After the reaction is completed, rotary evaporation is performed to remove toluene. Excess monomer is removed by repeated extraction with n-hexane. Rotary evaporation and vacuum drying are performed again to obtain the interface agent.

[0016] In one specific embodiment, the structure of the acryloylperylene is shown in Formula 2, and the general structure of the N-acryloylpiperidine is shown in Formula 3.

[0017]

[0018] In one specific embodiment, the silicone rubber is methyl vinyl silicone rubber, and the vinyl content of the methyl vinyl silicone rubber is 1-5 mol%.

[0019] In one specific embodiment, the aluminum layer in the copper-clad aluminum tube layer is a hollow aluminum tube with a thickness of 6-8 mm, the copper layer and the aluminum layer are tightly mechanically bonded, the wall thickness of the copper layer is 2-3 mm, the thickness of the shielding layer is 4-5 mm, and the thickness of the insulating layer is 5-7 mm.

[0020] In one specific embodiment, the tetraneedle-shaped zinc oxide whiskers have a diameter of 0.5–5 μm and a length of 10–50 μm; the fumed silica has an average particle size of 10–50 nm and a specific surface area of ​​70–400 m². 2 / g.

[0021] In one specific embodiment, the insulating layer, by weight, further comprises 0.2-2 parts of antioxidant, 0.5-5 parts of lubricant, 10-30 parts of flame retardant, and 0.5-5 parts of colorant; the antioxidant is a primary antioxidant and an auxiliary antioxidant in a mass ratio of (1-2):1; the primary antioxidant is a hindered phenolic antioxidant, and the auxiliary antioxidant is a phosphite antioxidant; the lubricant is any one or more of low molecular weight esters, metal soaps, stearic acid complex esters, and amides; the flame retardant is one or more of magnesium hydroxide and aluminum hydroxide; and the colorant is one or more of organic and inorganic colorants.

[0022] In one specific embodiment, the method for preparing the insulating layer includes the following steps:

[0023] Silicone rubber, fumed silica, boron nitride, tetraneedle zinc oxide whiskers, interface agent, and silane coupling agent are placed in a Hacker internal mixer and mixed for a period of time to obtain a premixed compound. The premixed compound is then transferred to a two-roll mill, where additives and vulcanizing agents are added. The roll gap is set to 0.35 mm, and cooling water is introduced into the rolls to reduce the mixing temperature to below 40°C. The mixture is then mixed for 20–40 minutes before sheeting. The insulating layer material is obtained by continuous vulcanization with high-pressure steam. The insulating layer material is then extruded onto the outside of the shielding layer to obtain the insulating layer.

[0024] Beneficial effects

[0025] This invention provides a high-efficiency heat dissipation busbar, whose heat dissipation performance is achieved through the composite material used in the insulation layer. The insulation layer composite material provided by this invention forms a three-dimensional thermally conductive pathway by adding boron nitride and tetra-needle zinc oxide whisker composite filler to silicone rubber, reducing interfacial thermal resistance. Furthermore, the perylene-based conjugated π-electron system in the interfacial agent can form π-π stacking between the boron nitride layers, while the excellent compatibility between the polysiloxane segments and the silicone rubber substrate optimizes the interfacial coupling between boron nitride and silicone rubber, further reducing interfacial thermal resistance. The introduction of acryloylpiperidine amide groups can form hydrogen bonds with the hydroxyl groups on the surfaces of boron nitride, fumed silica, and tetra-needle zinc oxide whiskers, filling interfacial pores and forming a "hydrogen bond-phonon" synergistic heat conduction pathway. This can improve thermal conductivity uniformity even with low filler content, thereby mitigating the negative impact of excessive thermally conductive filler on the mechanical properties of silicone rubber. In addition, the addition of tetraneedle-shaped zinc oxide whiskers and fumed silica ensures the strength of the silicone rubber composite material, while silane coupling agents and interface agents improve the toughness of the silicone rubber composite material, and at the same time improve the heat resistance and weather resistance of the silicone rubber composite material. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the synthetic route for interfacial agents;

[0027] Figure 2 The image shows the infrared spectrum of the hydrogen-containing polysiloxane and interface agent 1. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0030] The raw materials used in the examples and comparative examples are described below:

[0031] Silicone rubber: Methyl vinyl silicone rubber, model 112-7, vinyl content is 1.8-5 mol%, actual value is 3%, purchased from Dongjue Organosilicon;

[0032] Fumed silica: average particle size 50 nm, specific surface area 200 m² 2 / g, model AM-SiO2-021-2, purchased from Zhejiang Yamei Technology;

[0033] Boron nitride: Hexagonal boron nitride, model RH-N, average diameter 10μm, purchased from Dandong Rijin Technology Co., Ltd.;

[0034] Four needle-like zinc oxide whiskers: diameter 0.5-5um, length 10-50um, purchased from Hangzhou Jikang New Materials Co., Ltd.

[0035] Silane coupling agent: 3-aminopropyltriethoxysilane, KH-550, purchased from Shanghai Maclean;

[0036] Antioxidant: A mixture of antioxidant 1010 (SONOX) and antioxidant 168 (SONOX) in a mass ratio of 1:2, commercially available;

[0037] N-Acryloylpiperidine: Prepared in-house, as follows: Under anhydrous and oxygen-free conditions and with nitrogen purging, 0.11 mol piperidine and 0.12 mol triethylamine were dissolved in 100 mL of dichloromethane. While stirring, this solution was added dropwise over 3 hours to 7.5 mL of a dichloromethane solution containing acryloyl chloride, maintaining the solution at 3-5°C. After the addition was complete, the reaction mixture was stirred at room temperature for 24 hours. The resulting mixture was extracted with dichloromethane and water, and purified by column chromatography (n-hexane-ethyl acetate 1:1) to obtain a colorless to pale yellow liquid.

[0038]

[0039] Acryloylperylene: Under anhydrous and oxygen-free conditions, 1 mol of 3-aminoperylene and 3 mol of triethylamine were dissolved in 100 ml of chloroform. 1.05 mol of acryloyl chloride was slowly added dropwise under ice-water bath conditions. The mixture was then stirred at 60 °C for 2 hours. The solution was washed with saturated sodium bicarbonate solution and dried with anhydrous magnesium sulfate. The concentrate was dried under vacuum to obtain acryloylperylene.

[0040]

[0041] Lubricant: Zinc stearate, commercially available;

[0042] Interface agent 1: Self-made, prepared as follows: 0.2 mol octamethylcyclotetrasiloxane, 1.6 mol 2,4,6,8-tetramethylcyclotetrasiloxane, 0.1 mol 1,1,3,3-tetramethyldisiloxane, and 0.3 wt% initiator CF3SO3H (based on the total reactants) were added to a reactor and stirred for 24 h under a N2 atmosphere and at 25°C. After the reaction was complete, excess anhydrous sodium bicarbonate was added and stirred for 1 h, followed by excess anhydrous sodium sulfate and stirring for another 1 h. The mixture was then filtered and rotary evaporated to obtain a concentrated solution. Finally, the concentrated solution was vacuum dried for 6 h to obtain a colorless, transparent liquid hydrogen-containing polysiloxane with a yield of 78.6%. This was then further analyzed using... 1H-NMR integral calculations showed that the number of structural units m in the hydrogen-containing polysiloxane was 3 and n was 16; the viscosity measured by rotational rheometer was 0.03 Pa·s.

[0043] 1 mol of acryloylperylene, 1.72 mol of N-acryloylpiperidine, 5 ppm of caster catalyst, and 144 ml of toluene were sequentially added to a reactor. The mixture was stirred for 15 min under a nitrogen atmosphere while the temperature was raised to 80 °C. 0.1 mol of hydrogen-containing polysiloxane was dissolved in 144 ml of toluene and then added dropwise to the reactor using a constant-pressure dropping funnel, completing the addition within 90 min. The entire reaction was then heated to 100 °C and continued for 18–24 h. After the reaction was complete, rotary evaporation was performed to remove toluene, followed by repeated extraction with n-hexane to remove excess monomer. Rotary evaporation and vacuum drying were performed again to finally obtain interface agent 1. The synthetic route is as follows: Figure 1 As shown, the yield was 91.0%, and the viscosity was 9.2 Pa·s. The hydrogen-containing polysiloxane and interface agent 1 were analyzed by FT-IR using a Nicoleti S 50 Fourier transform infrared spectrometer (USA) with a resolution of 4 cm⁻¹. -1 The scanning range is 4000–500 cm. -1 The result is as follows Figure 2 As shown. From Figure 2 As can be seen, the infrared spectrum of interface agent 1, compared with that of hydrogen-containing polysiloxane, is located at 2163 cm⁻¹. -1 The Si-H characteristic peaks at 3267 cm⁻¹ disappear, and at 3267 cm⁻¹... -1 A stretching vibration peak belonging to acryloylperylene-NH appears at 3034 cm⁻¹. -1 An aromatic CH stretching vibration peak belonging to acryloylperylene appears at 1643 cm⁻¹. -1 The presence of a C=O stretching vibration peak at the point of origin, attributed to N-acryloylpiperidine, confirms the successful integration of acryloylperylene and N-acryloylpiperidine.

[0044] Interface agent 2: The preparation method is the same as that of interface agent 1, except that the amount of acryloylperylene added is 1.72 mol and the amount of N-acryloylpiperidine added is 1 mol;

[0045] Interface agent 3: The preparation method is the same as that of interface agent 1, except that acryloylperylene is not added;

[0046] Interface agent 4: The preparation method is the same as that of interface agent 1, except that N-acryloylpiperidine is not added;

[0047] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0048] Examples and Comparative Examples

[0049] A high-efficiency heat dissipation busbar includes a copper-clad aluminum tube layer, a shielding layer, and an insulation layer. The aluminum layer in the copper-clad aluminum tube layer is a hollow aluminum tube with a thickness of 7 mm. The copper layer is tightly mechanically bonded to the aluminum layer, and the copper layer has a wall thickness of 2 mm. The shielding layer is a copper wire braided shielding layer with a thickness of 4 mm. The insulation layer is a silicone rubber insulation layer with a thickness of 6 mm. The composition and proportions of the silicone rubber insulation layer are shown in Table 1. The preparation method is as follows:

[0050] Silicone rubber, fumed silica, boron nitride, tetraneedle zinc oxide whiskers, interface agent, and silane coupling agent are placed in a HAAKE Rheomix 600OS (Germany) and mixed for 30 minutes to obtain a premixed compound. The premixed compound is then transferred to a 6-inch two-roll mill (XK-160, Zhanjiang Guangyi Machinery Equipment Co., Ltd., China), where additives and vulcanizing agent DBPMH are added. The roll gap is set to 0.35 mm, and cooling water is introduced into the rolls to reduce the mixing temperature to below 40°C. The mixture is then mixed for 20–40 minutes, sheeted, and continuously vulcanized with 1.5 MPa high-pressure steam for 30 minutes to obtain an insulating layer material. This insulating layer material is then extruded over the shielding layer to obtain the insulating layer.

[0051] Table 1. Specific composition and proportions (parts by weight) of the insulating layer material.

[0052]

[0053] The insulating layer materials prepared in the examples and comparative examples were subjected to the following performance tests, and the results are shown in Table 2.

[0054] 1. Bending strength: The bending strength of the specimen is tested according to GB / T 9341-2008 "Determination of bending properties of plastics" for insulating materials. The specimen size is 80mm×10mm×4mm.

[0055] 2. Elongation at break: According to the national standard GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", the insulation material was cut into dumbbell shape as required and tested using a SANS electronic tensile testing machine.

[0056] 3. Thermal conductivity: The thermal conductivity of the sample was tested according to the method of GB / T 10297-2015 "Determination of thermal conductivity of non-metallic solid materials - hot wire method". The sample size was 10mm×10mm×2mm.

[0057] 4. Electrical insulation performance: The volume resistivity of the sample was tested in accordance with GB / T 31838.2-2019 "Dielectric and resistive properties of solid insulating materials - Part 2: Resistive properties".

[0058] 5. Heat resistance: The test was conducted in accordance with the national standard GB / T 6553-2003 Test method for evaluating the resistance of electrical insulation materials to tracking and corrosion under harsh environmental conditions. A 4.5kV voltage was applied to both ends of the insulation material while a dirty liquid was dripped on it. The time required for the sample to burn through was tested. The longer the burn-through time, the better the heat resistance.

[0059] Table 2 Performance test results of the examples and comparative examples

[0060]

[0061]

[0062] As can be seen from the performance of the examples and comparative examples, the silicone rubber composite obtained in the examples has better thermal conductivity and heat resistance, and its mechanical properties and insulation properties do not decrease significantly. As a result, the busbar prepared has a good heat dissipation effect and can effectively extend the service life of the cable.

[0063] In Comparative Example 1, the interface agent modification did not include acryloylperylene, and the interface coupling between the thermally conductive filler such as boron nitride and the silicone rubber substrate was poor, resulting in a significantly lower thermal conductivity than in Example 3.

[0064] In Comparative Example 2, the interface agent modification did not include N-acryloylpiperidine. When the number of peryl groups is too large, they are prone to stacking and forming conductive pathways, which affects the insulation performance of the composite material.

[0065] Comparative Example 3, without the addition of tetra-needle zinc oxide whiskers, showed inferior boron nitride dispersibility compared to Example 3.

[0066] Comparative Examples 4 and 5 did not contain silane coupling agents and interface agents, respectively. Their interface effects were poor, and their filler dispersion performance was poor. When the total amount of filler did not reach the percolation threshold, the improvement in the thermal conductivity of the material was not significant.

[0067] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-efficiency heat dissipation busbar, characterized in that, It includes a copper-clad aluminum tube layer, a shielding layer, and an insulating layer. The insulating layer, by weight, comprises 100-200 parts silicone rubber, 20-30 parts fumed silica, 20-30 parts boron nitride, 10-25 parts tetraneedle-shaped zinc oxide whiskers, 15-30 parts interface agent, and 1-5 parts silane coupling agent. The interface agent is prepared by: S1. Octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane and an initiator are added to a reactor and stirred under N2 atmosphere and room temperature. After the reaction is completed, excess anhydrous sodium bicarbonate and excess anhydrous sodium sulfate are added. Then, the mixture is filtered, rotary evaporated and vacuum dried to obtain hydrogen-containing polysiloxane. S2. Acryloylperylene, N-acryloylpiperidine, caster catalyst and toluene are added to the reactor in sequence. The mixture is stirred under N2 atmosphere and heated to 70~90℃. The hydrogen-containing polysiloxane is dissolved in toluene and then added dropwise to the reactor using a constant pressure dropping funnel. The mixture is heated to 100~120℃ and the reaction is continued for 18~24 h. After the reaction is completed, rotary evaporation is performed to remove toluene. Excess monomer is removed by repeated extraction with n-hexane. Rotary evaporation and vacuum drying are performed again to obtain the interface agent. The interface agent includes a structure with the general formula shown in Formula 1: ； Equation 1, where m is 2~4, n is 10~20, and a is 5~15.

2. The high-efficiency heat dissipation busbar as described in claim 1, characterized in that, The shielding layer is any one of copper foil shielding layer, copper wire braided shielding layer, aluminum foil shielding layer, and aluminum wire braided shielding layer.

3. The high-efficiency heat dissipation busbar as described in claim 1, characterized in that, The silicone rubber is methyl vinyl silicone rubber, and the vinyl content of the methyl vinyl silicone rubber is 1~5 mol%.

4. The high-efficiency heat dissipation busbar as described in claim 1, characterized in that, The aluminum layer in the copper-clad aluminum tube layer is a hollow aluminum tube with a thickness of 6-8 mm. The copper layer and the aluminum layer are tightly mechanically bonded together. The wall thickness of the copper layer is 2-3 mm. The thickness of the shielding layer is 4-5 mm. The thickness of the insulating layer is 5-7 mm.

5. The high-efficiency heat dissipation busbar as described in claim 1, characterized in that, The tetraneedle-shaped zinc oxide whiskers have a diameter of 0.5–5 μm and a length of 10–50 μm; the fumed silica has an average particle size of 10–50 nm and a specific surface area of ​​70–400 m². 2 / g.

6. The high-efficiency heat dissipation busbar as described in claim 1, characterized in that, The insulating layer, by weight, further comprises 0.2-2 parts antioxidant, 0.5-5 parts lubricant, 10-30 parts flame retardant, and 0.5-5 parts colorant; the antioxidant is a primary antioxidant and an auxiliary antioxidant in a mass ratio of (1-2):1; the primary antioxidant is a hindered phenolic antioxidant, and the auxiliary antioxidant is a phosphite antioxidant; the lubricant is any one or more of low molecular weight esters, metal soaps, stearic acid complex esters, and amides; the flame retardant is one or more of magnesium hydroxide and aluminum hydroxide; and the colorant is one or more of organic and inorganic colorants.

7. The high-efficiency heat dissipation busbar as described in any one of claims 1 to 5, characterized in that, The method for preparing the insulating layer includes the following steps: Silicone rubber, fumed silica, boron nitride, tetraneedle zinc oxide whiskers, interface agent, and silane coupling agent are placed in a Hacker internal mixer and mixed for a period of time to obtain a premixed compound. The premixed compound is then transferred to a two-roll mill, where additives and vulcanizing agents are added. The roll gap is set to 0.35 mm, and cooling water is introduced into the rolls to reduce the mixing temperature to below 40°C. The mixture is then mixed for 20-40 minutes before sheeting. The insulating layer material is obtained by continuous vulcanization with high-pressure steam. The insulating layer material is then extruded onto the outside of the shielding layer to obtain the insulating layer.

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