Preparation method of composite heat-conducting adhesive, composite heat-conducting adhesive and battery

Abstract

The invention provides a preparation method of a composite heat-conducting adhesive, the composite heat-conducting adhesive and a battery, and the preparation method comprises the following steps: adding graphene slurry into a heat-conducting adhesive matrix material, and uniformly stirring for the first time to obtain a premix; and adding a hardening agent into the premix, and stirring for the second time to obtain the composite heat-conducting adhesive. The problem that in the prior art, the heat conduction performance of composite heat-conducting glue is insufficient is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal conductive adhesive preparation, and in particular to a preparation method of a composite thermal conductive adhesive, the composite thermal conductive adhesive and a battery. Background Art

[0002] Current large lithium-ion battery packs in electric vehicles and energy storage containers generate significant heat during the charging and discharging process. This heat must be released promptly to prevent excessive battery temperature rise, significantly reducing battery cycle life, and even leading to thermal runaway. However, as energy density requirements continue to rise, the space available for battery cooling systems is significantly compressed, necessitating the design of more efficient heat dissipation systems. This is particularly true at high-rate charge and discharge rates. For example, 2C charge and discharge generates approximately four times the heat of 1C, and 3C charge and discharge generates approximately nine times the heat of 1C. Dissipating the heat from battery packs during long periods of high-rate charge and discharge is crucial, and efficient heat dissipation in high-rate charge and discharge battery systems remains a technical challenge for the industry.

[0003] With respect to the above-mentioned problems in the prior art, no effective technical solution has been proposed yet. Summary of the Invention

[0004] The main purpose of the present invention is to provide a preparation method of a composite thermally conductive adhesive, a composite thermally conductive adhesive and a battery, so as to solve the problem of insufficient thermal conductivity of the composite thermally conductive adhesive in the prior art.

[0005] In order to achieve the above-mentioned object, according to one aspect of the present invention, a method for preparing a composite thermally conductive adhesive is provided, comprising: adding a graphene slurry to a thermally conductive adhesive matrix material, and stirring the premixture for the first time to obtain a premixture; adding a hardener to the premixture, and stirring the premixture for the second time to obtain a composite thermally conductive adhesive.

[0006] Furthermore, the thermal conductive adhesive matrix material is at least one of epoxy resin, silicone, polyurethane, acrylate, and polyimide.

[0007] Furthermore, the hardener is selected from at least one of aliphatic amines, aromatic amines, phthalic anhydride, maleic anhydride, and phenolic resin.

[0008] Furthermore, during the first stirring process, the stirring speed is 300 to 1500 r / min, and the stirring time is 15 to 30 min.

[0009] Furthermore, during the second stirring process, the stirring speed is 300 to 1500 r / min, and the stirring time is 3 to 5 minutes.

[0010] Furthermore, before adding the hardener to the premix, the preparation method further comprises: adding at least one of a thermal conductive material, nanoparticles, a coupling agent, and a surface treatment agent to the premix.

[0011] Furthermore, the thermal conductive material is at least one of silver powder, copper powder, aluminum powder, boron nitride, carbon nanotubes, and diamond powder, and / or the nanoparticles are at least one of silicon dioxide, aluminum oxide, and zinc oxide, and / or the coupling agent is at least one of a silane coupling agent and a titanate coupling agent, and / or the surface treatment agent is a polyelectrolyte.

[0012] Furthermore, in the process of adding the graphene slurry into the thermal conductive adhesive matrix material, an ultrasonic assisted dispersion process is used for dispersion.

[0013] Furthermore, the preparation method also includes: performing oxidation treatment or amination treatment on the graphene slurry and then adding it to the thermal conductive adhesive matrix material.

[0014] Furthermore, the graphene slurry is oxidized and treated, including the following steps: adding graphite powder to concentrated sulfuric acid under ice bath conditions, then slowly adding potassium permanganate and stirring to fully oxidize the graphite powder; gradually adding water to dilute the reaction mixture, then adding hydrogen peroxide to terminate the reaction, followed by multiple water washing and centrifugation until the pH value of the washing liquid is close to neutral; drying the graphene oxide, and then dispersing it in a solvent using an ultrasonic or high-speed mixer to form a uniform graphene oxide slurry.

[0015] Furthermore, the mixture obtained after the second stirring is subjected to vacuum degassing, and then cured at a preset temperature and for a preset time to obtain a composite thermal conductive adhesive.

[0016] According to one aspect of the present invention, a composite thermally conductive adhesive is provided. The composite thermally conductive adhesive is prepared using the above-mentioned method for preparing the composite thermally conductive adhesive.

[0017] According to another aspect of the present invention, a battery is provided, wherein the outer side of the battery is coated with a composite thermally conductive adhesive, the composite thermally conductive adhesive being the above-mentioned composite thermally conductive adhesive, the composite thermally conductive adhesive being coated on the bottom of the battery module, and / or the composite thermally conductive adhesive being coated on at least a portion of the side wall of the battery module and starting from the bottom end of the battery module.

[0018] Furthermore, the height of the adhesive layer on the side of the module is 5 to 50 mm, and / or the thickness of the adhesive layer on the bottom of the module is 1 to 8 mm.

[0019] By applying the technical solution of the present invention, graphene slurry is added to the thermal conductive adhesive matrix material, and a hardener is added to the obtained premix, and a composite thermal conductive adhesive is obtained after a second stirring. The thermal conductive adhesive can fully utilize the good thermal conductivity of graphene, improve the heat release effect of the battery box under long-term high-rate charging and discharging, and thus greatly improve the thermal conductivity performance of the thermal conductive adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 A schematic flow chart showing an embodiment of a method for preparing a composite thermally conductive adhesive according to the present invention is shown;

[0022] Figure 2 A schematic diagram showing a temperature curve of an embodiment of a charge-discharge cycle test of a composite thermally conductive adhesive according to the present invention at a 2C rate;

[0023] Figure 3 A schematic structural diagram of an embodiment of a battery module coated with a composite thermally conductive adhesive according to the present invention is shown. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of this application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0028] Combine Figures 1 to 3 As shown, according to a specific embodiment of the present application, a method for preparing a composite thermally conductive adhesive is provided.

[0029] like Figure 1 As shown, the method includes:

[0030] Step S1, adding graphene slurry to the thermal conductive adhesive matrix material, and stirring it for the first time to obtain a premix;

[0031] Step S2, adding a hardener to the premix, and obtaining a composite thermal conductive adhesive after a second stirring.

[0032] By applying the technical solution of the present invention, graphene slurry is added to the thermal conductive adhesive matrix material, and a hardener is added to the obtained premix, and a composite thermal conductive adhesive is obtained after a second stirring. The thermal conductive adhesive can fully utilize the good thermal conductivity of graphene, improve the heat release effect of the battery box under long-term high-rate charging and discharging, and thus greatly improve the thermal conductivity performance of the thermal conductive adhesive.

[0033] Furthermore, the thermally conductive adhesive matrix material is at least one of epoxy resin, silicone, polyurethane, acrylate, and polyimide. Epoxy resin is the base material for graphene composite thermally conductive adhesives primarily because of its excellent bonding properties, chemical stability, and hardness and heat resistance after curing. These properties make epoxy resin an ideal choice for thermally conductive adhesives. Furthermore, other types of polymer materials can also serve as matrices for graphene composite thermally conductive adhesives. For example, silicone, polyurethane, acrylate, and other materials can also serve as matrices, all of which are capable of supporting graphene and forming stable composite thermally conductive adhesives.

[0034] The above materials have good bonding properties and can firmly bond the battery module and the PACK box together to ensure effective heat conduction. The above materials should remain stable during the battery charging and discharging process, will not decompose or lose performance due to high temperature, and can be quickly cured under reasonable conditions. The shrinkage rate during the curing process and the hardness after curing need to be controlled within an appropriate range.

[0035] Furthermore, the hardener is selected from at least one of aliphatic amines, aromatic amines, phthalic anhydride, maleic anhydride, and phenolic resins. Hardeners, also known as curing agents or crosslinking agents, are key components used to transform polymer materials such as resins, adhesives, and coatings from a liquid to a solid state. They react with the polymer matrix to form a three-dimensional network structure, thereby enhancing the material's hardness, mechanical strength, and chemical resistance. In the preparation of graphene composite thermally conductive adhesives, different hardener types can be used in different resin systems.

[0036] Amine hardeners are the most commonly used curing agents for epoxy resins, including aliphatic amines, aromatic amines, etc. They are highly reactive and have the characteristics of fast curing, but some types of amine hardeners may cure slowly at low temperatures.

[0037] Anhydride hardeners react with epoxy resins to form ester bonds, making them suitable for applications requiring high thermal stability and chemical resistance. Common anhydrides include phthalic anhydride and maleic anhydride.

[0038] In the presence of a catalyst, phenolic resin can react with epoxy resin to form a cross-linked structure. This type of hardener can improve the heat resistance and electrical insulation of epoxy resin.

[0039] Urea hardeners: such as triethylene glycol diglycidyl ether. This type of hardener can react with epoxy resin to improve the heat resistance and mechanical strength of the cured product.

[0040] Furthermore, during the first stirring process, the stirring speed is 300 to 1500 r / min, and the stirring time is 15 to 30 min.

[0041] Furthermore, during the second stirring process, the stirring speed is 300 to 1500 r / min, and the stirring time is 3 to 5 minutes.

[0042] [Example 1]: The preparation method comprises the following steps:

[0043] Step 1: Weigh 700g of component A (epoxy resin), weigh 70g of graphene slurry, add it to component A, and stir at 500 rpm for 20 minutes at room temperature to obtain a primary thermal conductive adhesive;

[0044] Step 2: Add 300g of component B to the primary thermal conductive adhesive prepared in step 1, and stir at 500 rpm for 5 minutes at room temperature to obtain a graphene composite thermal conductive adhesive;

[0045] Step 3: Apply a 2.5mm thick and 20mm high graphene thermal conductive adhesive layer on the four sides of the bottom of the module;

[0046] Step 4: Evenly apply a 1.0-2.0mm thick layer of graphene composite thermal conductive adhesive on the bottom of the pack box, install the module with the bottom side coated with graphene thermal conductive adhesive into the pack box, apply vertical pressure to the module to completely exhaust the air from the bottom of the module, and control the thickness of the graphene thermal conductive adhesive layer between the bottom of the module and the pack box to less than 0.5mm;

[0047] Step 5: Leave the pack box at room temperature for 12 hours to allow the thermal adhesive to cure.

[0048] [Example 2]: The preparation method comprises the following steps:

[0049] Step 1: Weigh 750g of component A (epoxy resin), weigh 60g of graphene slurry, add it to component A, and stir at 500 rpm for 18 minutes at room temperature to obtain the primary thermal conductive adhesive;

[0050] Step 2: Add 250g of component B to the primary thermal conductive adhesive prepared in step 1, and stir at 500r / min for 5min at room temperature to obtain a graphene composite thermal conductive adhesive;

[0051] Step 3: Apply a 2.0mm thick and 15.0mm high graphene thermal conductive adhesive layer on the four sides of the bottom of the module;

[0052] Step 4: Evenly apply a 1.0-2.0mm thick layer of graphene composite thermal conductive adhesive on the bottom of the pack box, install the module with the bottom coated with graphene thermal conductive adhesive into the PAC box, apply vertical pressure to the module to completely exhaust the air from the bottom of the module, and control the thickness of the graphene thermal conductive adhesive layer between the bottom of the module and the pack box to less than 0.5mm;

[0053] Step 5: Leave the pack box at room temperature for 12 hours to allow the thermal adhesive to cure.

[0054] like Figure 2 The temperature curves of the composite thermal conductive adhesives prepared in Example 1 and Example 2 under 2C charge-discharge cycle test are shown. Figure 2 It can be seen that the temperature of Example 1 is higher than that of Example 2 in the cycle test.

[0055] Furthermore, before adding the hardener to the premix, the preparation method further comprises: adding at least one of a thermal conductive material, nanoparticles, a coupling agent, and a surface treatment agent to the premix.

[0056] Furthermore, the thermal conductive material is at least one of silver powder, copper powder, aluminum powder, boron nitride, carbon nanotubes, and diamond powder, and / or the nanoparticles are at least one of silicon dioxide, aluminum oxide, and zinc oxide, and / or the coupling agent is at least one of a silane coupling agent and a titanate coupling agent, and / or the surface treatment agent is a polyelectrolyte.

[0057] High thermal conductivity fillers, such as silver powder, copper powder, aluminum powder, boron nitride (BN), carbon nanotubes (CNT), diamond powder, etc. These fillers can form a synergistic effect with graphene and significantly improve the thermal conductivity of the composite material.

[0058] Adding nanoparticles such as silicon dioxide (SiO2), aluminum oxide (Al2O3), zinc oxide (ZnO), etc. can improve the dispersion of graphene in the matrix, increase the strength and toughness of the composite material, and also help improve thermal conductivity.

[0059] The use of coupling agents, such as silane coupling agents and titanate coupling agents, can improve the interfacial bonding between graphene and other fillers and the epoxy resin matrix, thereby improving the overall performance of the material, including thermal conductivity and mechanical strength.

[0060] In order to increase the toughness of the thermal conductive adhesive, toughening agents such as polyether, polysulfide, polyimide, etc. can be added to make the composite material less likely to break when subjected to mechanical stress, thereby improving its reliability and life.

[0061] Graphene surface treatment agents, such as surfactants and polyelectrolytes, can improve the surface properties of graphene, make it more evenly dispersed in the matrix, improve the compatibility of graphene with the matrix, and thus enhance the thermal conductivity of the material.

[0062] When adding the above ingredients, those skilled in the art can control the addition amount and mixing process as needed to ensure uniform dispersion of the filler while avoiding degradation of other important properties of the material, such as adhesion, curing speed or processability.

[0063] Furthermore, when adding graphene slurry to the thermal conductive adhesive matrix material, an ultrasonic-assisted dispersion process is used to disperse the graphene slurry. When adding the graphene slurry, ultrasonic-assisted dispersion is used to ensure that the graphene is evenly dispersed in the epoxy resin matrix, avoiding agglomeration and improving thermal conductivity.

[0064] Furthermore, the preparation method also includes: performing oxidation treatment or amination treatment on the graphene slurry and then adding it to the thermal conductive adhesive matrix material.

[0065] Furthermore, the graphene slurry is oxidized and treated, including the following steps: adding graphite powder to concentrated sulfuric acid under ice bath conditions, then slowly adding potassium permanganate and stirring to fully oxidize the graphite powder; gradually adding water to dilute the reaction mixture, then adding hydrogen peroxide to terminate the reaction, followed by multiple water washing and centrifugation until the pH value of the washing liquid is close to neutral; drying the graphene oxide, and then dispersing it in a solvent using an ultrasonic or high-speed mixer to form a uniform graphene oxide slurry.

[0066] Preparation of graphene oxide (Hummers method) steps:

[0067] 1. Raw material preparation: prepare graphite powder, concentrated sulfuric acid, potassium permanganate, hydrogen peroxide and other raw materials.

[0068] 2. Oxidation reaction: In an ice bath, add graphite powder to concentrated sulfuric acid, then slowly add potassium permanganate. Control the reaction temperature to avoid violent heat release. Stir for several hours to fully oxidize the graphite powder.

[0069] 3. Dilution and cleaning: Gradually add water to dilute the reaction mixture, then add hydrogen peroxide to terminate the reaction, followed by multiple water washing and centrifugation until the pH value of the cleaning solution is close to neutral.

[0070] 4. Drying and dispersion: Dry the graphene oxide and then disperse it in the solvent using ultrasound or a high-speed mixer to form a uniform graphene oxide slurry.

[0071] Preparation steps of amination graphene:

[0072] 1. Raw material preparation: prepare graphene oxide slurry, amination reagent (such as ethylenediamine) and solvent.

[0073] 2. Amination reaction: Under heating conditions, the graphene oxide slurry and the amination reagent are mixed and stirred for several hours to allow the amination reagent to react with the carboxyl or epoxy groups on the graphene oxide to form aminated graphene.

[0074] 3. Post-treatment: After the reaction is completed, use solvent to wash and centrifuge multiple times to remove unreacted amination reagent and by-products, and finally dry the aminated graphene.

[0075] Furthermore, the mixture obtained after the second stirring is subjected to vacuum degassing, and then cured at a preset temperature and for a preset time to obtain a composite thermal conductive adhesive.

[0076] Steps for mixing modified graphene with epoxy resin:

[0077] 1. Disperse modified graphene: Disperse the modified graphene in a solvent to form a uniform slurry.

[0078] 2. Premix component A: Gradually add the modified graphene slurry to the epoxy resin under low-speed stirring to ensure that the graphene is evenly dispersed in the resin.

[0079] 3. Add component B: Add the hardener to the premix and stir quickly to promote the curing reaction. Pay attention to controlling the stirring speed and time to avoid introducing too many bubbles.

[0080] 4. Degassing and curing: The mixture is vacuum degassing and then cured at a specific temperature and time to form a modified graphene composite thermal conductive adhesive.

[0081] After graphene is modified by the above method, the interfacial bonding force between graphene and epoxy resin can be significantly enhanced, thereby improving the thermal conductivity and mechanical properties of the composite material.

[0082] According to one aspect of the present invention, a composite thermally conductive adhesive is provided. The composite thermally conductive adhesive is prepared using the above-mentioned method for preparing the composite thermally conductive adhesive.

[0083] According to another aspect of the present invention, a battery is provided, wherein the outer side of the battery is coated with a composite thermally conductive adhesive, the composite thermally conductive adhesive being the above-mentioned composite thermally conductive adhesive, the composite thermally conductive adhesive being coated on the bottom of the battery module, and / or the composite thermally conductive adhesive being coated on at least a portion of the side wall of the battery module and starting from the bottom end of the battery module.

[0084] Furthermore, the height of the adhesive layer on the side of the module is 5 to 50 mm, and / or the thickness of the adhesive layer on the bottom of the module is 1 to 8 mm.

[0085] In an optional embodiment, a method for preparing a graphene composite thermally conductive adhesive includes: adding graphene slurry to component A (epoxy resin: i.e., the thermally conductive adhesive matrix material), stirring and dispersing the graphene slurry uniformly, and then adding component B (hardener) and stirring rapidly, specifically comprising the following steps:

[0086] At room temperature, add epoxy resin and graphene slurry in a ratio of a:b, stir at 300-1500 r / min for 15-30 min to mix evenly, and obtain a primary glue (i.e., a premix);

[0087] Under a constant temperature, continue to add component B to the primary glue and stir at 300-1500 r / min for 3-5 minutes to mix evenly to obtain a graphene composite thermal conductive glue;

[0088] The bottom of the battery module in the battery box is covered with a graphene thermal conductive adhesive layer, and the bottom and side surfaces of the battery module are coated with a thick graphene composite thermal conductive adhesive with a height of 0.5 to 5 cm;

[0089] Furthermore, the thickness of the thermal conductive adhesive layer at the bottom of the battery module in the battery box is 0.2±1mm;

[0090] Furthermore, the thickness of the thermal conductive adhesive layer at the bottom of the battery module in the battery box is 0.1 to 0.5 mm;

[0091] Furthermore, the height of the adhesive layer on the bottom and side of the module is 5 to 50 mm;

[0092] Furthermore, the thickness of the adhesive layer on the bottom side of the module is 1 to 8 mm.

[0093] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0094] Graphene has excellent thermal conductivity. The thermal conductivity of pure, defect-free single-layer graphene is as high as 5300W / mk. By preparing a graphene composite thermal conductive adhesive, the thermal conductivity of the thermal conductive adhesive is significantly improved. The thermal conductive adhesive is adjusted from the conventional bottom coating structure to a bottom coating and bottom side coating structure, and the thickness of the thermal conductive adhesive coating is optimized. Using the graphene composite thermal conductive adhesive prepared in the above embodiment, the battery box can control the battery temperature rise below 40°C during 3C cycle charge and discharge, the temperature rise can be controlled below 35°C during 2C cycle, and the temperature rise can be controlled below 30°C during 1C cycle.

[0095] The above embodiments can also be used in the field of device technology, that is, according to another aspect of the present invention, one is provided.

[0096] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0097] In addition to the above, it should be noted that references to "one embodiment," "another embodiment," "an embodiment," and the like in this specification refer to specific features, structures, or characteristics described in conjunction with that embodiment as included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that such feature, structure, or characteristic, when implemented in conjunction with other embodiments, also falls within the scope of the present invention.

[0098] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0099] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing a composite thermally conductive adhesive, characterized in that: include: Adding graphene slurry to the thermal conductive adhesive matrix material and stirring it evenly for the first time to obtain a premix; A hardener is added to the premix, and the composite thermal conductive adhesive is obtained after a second stirring.

2. The method for preparing the composite thermally conductive adhesive according to claim 1, wherein: The thermal conductive adhesive matrix material is at least one of epoxy resin, silicone, polyurethane, acrylate, and polyimide.

3. The method for preparing the composite thermally conductive adhesive according to claim 1, wherein: The hardener is selected from at least one of aliphatic amines, aromatic amines, phthalic anhydride, maleic anhydride, and phenolic resin.

4. The method for preparing the composite thermally conductive adhesive according to claim 1, wherein: During the first stirring process, the stirring speed is 300 to 1500 r / min, and the stirring time is 15 to 30 minutes.

5. The method for preparing the composite thermally conductive adhesive according to claim 1, wherein: During the second stirring process, the stirring speed is 300-1500 r / min, and the stirring time is 3-5 min.

6. The method for preparing the composite thermally conductive adhesive according to any one of claims 1 to 5, characterized in that: Before adding the hardener to the premix, the preparation method further comprises: At least one of a thermal conductive material, nanoparticles, a coupling agent, and a surface treatment agent is added to the premix.

7. The method for preparing the composite thermally conductive adhesive according to claim 6, wherein: The thermal conductive material is at least one of silver powder, copper powder, aluminum powder, boron nitride, carbon nanotubes, and diamond powder, and / or the nanoparticles are at least one of silicon dioxide, aluminum oxide, and zinc oxide, and / or the coupling agent is at least one of a silane coupling agent and a titanate coupling agent, and / or the surface treatment agent is a polyelectrolyte.

8. The method for preparing the composite thermally conductive adhesive according to claim 1, wherein: In the process of adding graphene slurry into the thermal conductive adhesive matrix material, an ultrasonic assisted dispersion process is used for dispersion.

9. The method for preparing the composite thermally conductive adhesive according to claim 8, characterized in that: The preparation method further comprises: performing an oxidation treatment or an amination treatment on the graphene slurry and then adding the graphene slurry to the thermal conductive adhesive matrix material.

10. The method for preparing the composite thermally conductive adhesive according to claim 8, characterized in that: The oxidation treatment of the graphene slurry comprises the following steps: In an ice bath, graphite powder was added to concentrated sulfuric acid, followed by slow addition of potassium permanganate, with stirring to fully oxidize the graphite powder. Gradually add water to dilute the reaction mixture, then add hydrogen peroxide to terminate the reaction, followed by multiple water washings and centrifugation until the pH value of the washing solution is close to neutral; The graphene oxide is dried and then dispersed in a solvent using an ultrasonic wave or a high-speed mixer to form a uniform graphene oxide slurry.

11. The method for preparing the composite thermally conductive adhesive according to claim 1, wherein: The mixture obtained after the second stirring is subjected to vacuum degassing, and then cured at a preset temperature and for a preset time to obtain the composite thermal conductive adhesive.

12. A composite thermally conductive adhesive, characterized in that: The composite thermally conductive adhesive is prepared by the preparation method of the composite thermally conductive adhesive according to any one of claims 1 to 10.

13. A battery, wherein the outer side of the battery is coated with the composite thermal conductive adhesive, characterized in that: The composite thermally conductive adhesive is the composite thermally conductive adhesive described in claim 12, and the composite thermally conductive adhesive is applied to the bottom of the battery module, and / or the composite thermally conductive adhesive is applied to at least part of the side wall of the battery module and starts to be applied from the bottom end of the battery module.

14. The battery according to claim 13, characterized in that The height of the adhesive layer on the side of the module is 5 to 50 mm, and / or the thickness of the adhesive layer on the bottom of the module is 1 to 8 mm.

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