Method and device for testing coating performance of battery pack heat-conducting glue

Abstract

The invention relates to the field of power battery packs, in particular to a method and device for testing the coating performance of heat-conducting glue of a battery pack, and the method comprises the following steps: laying a first isolating membrane in a heat-conducting glue coating area of a battery pack box body; gluing the battery pack box body on the surface of the first isolating membrane according to the preset amount of the heat-conducting glue; after the gluing is completed, laying a second isolating membrane on the surface of the heat-conducting glue, and fixedly assembling a pressure applying assembly on the battery pack box body until the heat-conducting glue is completely cured; and after the heat-conducting glue is cured, the pressing assembly is firstly taken out, and then the cured heat-conducting glue block is taken out for coating performance evaluation. The method has the advantages of low cost and high efficiency.

Description

Technical Field

[0001] The present invention relates to the field of power battery packs, and specifically relates to a method and device for testing the coating performance of a thermal conductive adhesive for a battery pack. Background Art

[0002] At present, the mainstream integration methods of power batteries adopt CTP, CTV, and CTC integration structures. The integration structure form cancels the traditional mechanical connection method and replaces it with an adhesive connection using a structural adhesive. Due to the requirements of its thermal management function, a thermal conductive adhesive with dual functions of bonding and heat conduction is adopted.

[0003] To verify the gluing process, we need to consider both the bonding strength and the heat conduction effect (i.e., achieving a certain adhesive thickness and coverage rate after curing in the box), and also consider the material cost of auxiliary materials, that is, minimizing the amount of adhesive used. Therefore, in the process verification stage, to support the determination of the adhesive application amount, the adhesive application trajectory, and the evaluation of the actual effect of curing after the battery cells are put into the box, a test method for verifying the coating performance is required.

[0004] In the prior art, enterprises often use real samples according to the normal assembly process of putting them into the box, take out the battery cells after the adhesive is cured, and then evaluate the gluing effect. This method makes all samples need to be scrapped after verification because the product does not have disassembly and repairability. If the effect of the verified process parameters does not meet the design requirements, additional samples need to be supplemented for further verification, resulting in high cost and low efficiency of this verification method. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and device for testing the coating performance of a thermal conductive adhesive for a battery pack, which have the advantages of low cost and high efficiency.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] In the first aspect, the present invention provides a method for testing the coating performance of a thermal conductive adhesive for a battery pack, which includes:

[0008] Laying a first isolation film on the thermal conductive adhesive coating area of the battery pack box body;

[0009] Applying adhesive to the battery pack box body according to the preset amount of the thermal conductive adhesive on the surface of the first isolation film;

[0010] After the adhesive application is completed, laying a second isolation film on the surface of the thermal conductive adhesive, and fixedly assembling the pressing component to the battery pack box body, and maintaining it until the thermal conductive adhesive is completely cured;

[0011] After the thermal conductive adhesive is cured, first take out the pressing component, and then take out the cured thermal conductive adhesive block for coating performance evaluation.

[0012] Further, the materials of the first isolation film and the second isolation film are independently polyethylene, polypropylene, polyvinyl chloride, or polyvinylidene chloride; and / or, the thicknesses of the first isolation film and the second isolation film are independently 0.02 mm to 0.08 mm.

[0013] Further, the calculation formula for the preset amount of the thermal conductive adhesive is: In the formula, Q is the preset amount of the thermal conductive adhesive, A is the area of the thermal conductive adhesive coating region, D is the preset thickness after the thermal conductive adhesive is cured, and is the correction coefficient.

[0014] Further, the evaluation of the coating performance includes the evaluation of the coverage rate, the evaluation of the thickness, and the evaluation of the uniformity.

[0015] Further, the evaluation of the coverage rate specifically includes: after taking out the cured thermal conductive adhesive block, obtaining the theoretical coverage area S2 and the coverage area S1 on the side of the thermal conductive adhesive block close to the first isolation film, and calculating the coverage rate of the thermal conductive adhesive according to the calculation formula

[0016] Further, the first isolation film is transparent, and a grid pattern is provided on the first isolation film; the obtaining of the coverage area S1 includes: observing the coincidence of the grid pattern on the first isolation film and the thermal conductive adhesive block, counting the number of grids covered by the thermal conductive adhesive, and then calculating the coverage area S1 on the side of the thermal conductive adhesive block close to the first isolation film according to the area of the grids.

[0017] Further, the evaluation of the thickness specifically includes: after taking out the cured thermal conductive adhesive block, measuring the measurement points at different positions on the thermal conductive adhesive block with a measuring tool to obtain thickness measurement data; comparing the thickness measurement data with the preset standard thickness to evaluate whether the coating thickness of the thermal conductive adhesive meets the preset requirements.

[0018] Further, the evaluation of the uniformity specifically includes: after taking out the cured thermal conductive adhesive block, measuring the measurement points at different positions on the thermal conductive adhesive block with a measuring tool to obtain thickness measurement data; comparing the thickness measurement data of each measurement point with the preset thickness range to evaluate whether the coating uniformity of the thermal conductive adhesive meets the preset requirements.

[0019] In a second aspect, the present invention provides a coating performance test device for a battery pack thermal conductive adhesive, which includes:

[0020] A battery pack box body, including a thermal conductive adhesive coating region;

[0021] A first isolation film, laid on the thermal conductive adhesive coating region of the battery pack box body, for isolating the thermal conductive adhesive block and the battery pack box body;

[0022] ​Second isolation film: After the glue application is completed, a second isolation film is laid on the surface of the thermal conductive glue to isolate the thermal conductive glue block and the pressing component.

[0023] Pressing component: It is used to simulate the battery pack module.

[0024] Furthermore, the pressing component includes several cell components arranged at intervals; each cell component includes an end plate, a cell monomer, and a simulated cell. A plurality of cell monomers are stacked and fixed between two end plates along their thickness directions, and the simulated cell is arranged between two stacked cell monomers, and a connecting portion adapted to the disassembly tool is provided on the simulated cell.

[0025] The present invention has the following unexpected beneficial effects: In the test method of the present invention, since the first isolation film is laid on the thermal conductive glue coating area of the battery pack box before the glue application, and the second isolation film is laid on the surface of the thermal conductive glue after the glue application is completed. The first isolation film is used to isolate the thermal conductive glue block and the battery pack box, and the second isolation film is used to isolate the thermal conductive glue block and the pressing component, thereby avoiding the direct adhesion of the thermal conductive glue block to the battery pack box and the pressing component of the test sample, enabling the battery pack box and the pressing component to be reused. With such a setting, the test cost is reduced. When the coating performance of the thermal conductive glue of the battery pack does not meet the preset requirements, there is no need to remanufacture the test sample separately, improving the test efficiency. And by introducing the use of the isolation film, after the test is completed, the cleaning work changes from laboriously cleaning the thermal conductive glue on the sample to easily removing the pressing component and the cured thermal conductive glue block, greatly reducing the work burden of the test personnel. Description of the Drawings

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0027] Figure 1 Shows a schematic flow chart of the test method for the coating performance of the thermal conductive glue of the battery pack according to the embodiment of the present invention.

[0028] Figure 2 Shows a schematic structural diagram of the test device for the coating performance of the thermal conductive glue of the battery pack according to the embodiment of the present invention.

[0029] Figure 3 Shows a schematic structural diagram of the pressing component according to the embodiment of the present invention.

[0030] Figure 4 Shows a schematic cross-sectional view of the formed thermal conductive glue block according to the embodiment of the present invention. Detailed Embodiments

[0031] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, rather than for limiting the protection scope of the present invention.

[0032] In one embodiment, as shown in Figure 1 the present invention provides a method for testing the coating performance of a battery pack thermal conductive adhesive, which includes:

[0033] Laying a first isolation film on the thermal conductive adhesive coating area of the battery pack box body.

[0034] Applying the thermal conductive adhesive to the battery pack box body according to the preset dosage of the thermal conductive adhesive on the surface of the first isolation film.

[0035] After the adhesive application is completed, laying a second isolation film on the surface of the thermal conductive adhesive, and fixedly assembling the pressing component to the battery pack box body, and maintaining until the thermal conductive adhesive is completely cured.

[0036] After the thermal conductive adhesive is cured, first remove the pressing component, and then remove the cured thermal conductive adhesive block for coating performance evaluation.

[0037] The present invention uses the first isolation film to isolate the thermal conductive adhesive block from the battery pack box body, and uses the second isolation film to isolate the thermal conductive adhesive block from the pressing component, thereby avoiding the direct adhesion of the thermal conductive adhesive block to the battery pack box body and the pressing component of the test sample, enabling the battery pack box body and the pressing component to be reused. With such a setting, the battery pack box body and the pressing component can be reused, and there is no need to frequently replace the test sample due to the adhesion of the thermal conductive adhesive, saving the cost of remanufacturing new samples and significantly reducing the cost during long-term tests. At the same time, when the coating performance of the battery pack thermal conductive adhesive does not meet the preset requirements, the process of remaking the test sample is cumbersome and time-consuming. Now, there is no need to remanufacture, and a new round of tests can be directly carried out, greatly accelerating the test progress, helping the R & D personnel quickly obtain the test results, and timely adjusting the thermal conductive adhesive formula or coating process. Moreover, by introducing the use of the isolation film, after the test, the cleaning work changes from laboriously cleaning the thermal conductive adhesive on the sample to easily removing the pressing component and the cured thermal conductive adhesive block, greatly reducing the work burden of the test personnel.

[0038] As a preferred embodiment of the present invention, the materials of the first isolation film and the second isolation film are independently polyethylene, polypropylene, polyvinyl chloride, or polyvinylidene chloride.

[0039] Polyethylene (PE): It has good chemical stability, is resistant to the erosion of most acids and alkalis, has good barrier properties against the chemicals in the thermal conductive adhesive, and is not easily chemically reactive with the thermal conductive adhesive, thus ensuring the accuracy of the test. Moreover, the polyethylene material is soft in texture, easy to lay, and can closely adhere to the surface of the battery pack box body and the thermal conductive adhesive, effectively playing an isolation role.

[0040] Polypropylene (PP): It has relatively high strength and rigidity. During the test process, even under a certain pressure, it is not easily damaged and can continuously and effectively isolate the thermal conductive adhesive from the battery pack box body and the pressure-applying component.

[0041] Polyvinyl chloride (PVC): It has good weather resistance and abrasion resistance, can maintain stable performance in the test environment, and is not easily aged or damaged. And its cost is relatively low. Choosing polyvinyl chloride as the material of the isolation film can reduce the test cost to a certain extent.

[0042] Polyvinylidene chloride (PVDC): It has excellent barrier properties and has good barrier effects on gases, water vapor, etc. This may have a certain protective effect on the curing environment of the thermal conductive adhesive, preventing external factors from interfering with the curing process of the thermal conductive adhesive, ensuring that the thermal conductive adhesive can cure according to the expected performance, and thus making the evaluation of the coating performance more accurate.

[0043] The thickness of the first isolation film and the second isolation film is independently 0.02 mm to 0.08 mm. The relatively thin thickness of the isolation film makes it easier to operate during the laying process, can more closely adhere to the surface of the battery pack box body and the thermal conductive adhesive, reduce the extra gaps caused by the thickness of the isolation film, and avoid affecting the actual coating effect and curing form of the thermal conductive adhesive. At the same time, the relatively thin isolation film has a relatively low cost and can also reduce the test cost to a certain extent. At the same time, due to the certain thickness of the isolation film, its strength and toughness are guaranteed. It is not easily damaged during the test process and can remain intact even under the pressure of the pressure-applying component or the stress during the curing process of the thermal conductive adhesive, and continue to play an isolation role. And the appropriate thickness is also convenient for taking out the isolation film together with the thermal conductive adhesive block after the test, and it is not difficult to operate because it is too thin.

[0044] Through the limitation of the material and thickness of the isolation film, the present invention ensures the smooth progress of the test and the accuracy of the results from multiple aspects. The appropriate material ensures the chemical compatibility and physical isolation effect between the isolation film and the thermal conductive adhesive, and the reasonable thickness range takes into account various factors such as operation convenience, strength, and the impact on the test results. At the same time, the "independent" selection method enables flexible matching of the materials and thicknesses of the first isolation film and the second isolation film according to specific requirements and conditions in the actual test, further optimizing the test scheme.

[0045] As a preferred embodiment of the present invention, the calculation formula for the preset dosage of the thermal conductive adhesive is: In the formula, Q is the preset amount of thermal conductive adhesive, A is the area of the coating region of the thermal conductive adhesive, D is the preset thickness after curing of the thermal conductive adhesive, and

[0046] The area A of the coating region of the thermal conductive adhesive directly determines the size of the area to be covered. Under the same other conditions, the larger the coating area, the more thermal conductive adhesive is naturally required. By incorporating the coating area into the calculation formula, the corresponding amount of thermal conductive adhesive can be accurately calculated according to the actual test requirements, ensuring that the thermal conductive adhesive can fully cover the required area and meet the requirements for the coating range of the thermal conductive adhesive in the test.

[0047] The preset thickness D after curing of the thermal conductive adhesive is one of the important factors affecting its amount. Different application scenarios and test purposes may have different requirements for the thickness of the thermal conductive adhesive. For example, in some cases where high thermal conductivity is required, a thicker layer of thermal conductive adhesive may be needed to ensure better heat conduction effect. Considering the preset thickness after curing in the calculation formula enables the determination of the appropriate amount of thermal conductive adhesive according to specific performance requirements, thus ensuring that the test results can accurately reflect the coating performance of the thermal conductive adhesive under specific thickness conditions.

[0048] The correction coefficient is very necessary. In the actual glue coating process, there are many factors that are difficult to accurately calculate, such as the glue coating method, the fluidity of the glue solution, the surface adsorption, etc. These factors will all affect the final amount of thermal conductive adhesive. The correction coefficient can comprehensively consider and adjust these uncertain factors, making the calculated preset amount of thermal conductive adhesive closer to the actual required amount, and improving the accuracy and reliability of the test.

[0049] By combining the coating area, the preset thickness after curing, and the correction coefficient, the preset amount of thermal conductive adhesive can be calculated more accurately. This helps to accurately prepare the required amount of thermal conductive adhesive before the test, avoiding inaccurate test results or waste of resources caused by too much or too little amount. And due to the existence of the correction coefficient, this formula has a certain degree of adjustability. Under different test conditions and requirements, the correction coefficient can be adjusted according to the actual situation, so that the formula can adapt to various complex test scenarios and improve its versatility and practicality.

[0050] This calculation formula provides clear guidance for the testers, enabling them to accurately calculate the amount of thermal conductive adhesive based on specific test parameters when conducting the coating performance test of the battery pack thermal conductive adhesive, standardizing the test operation, and ensuring the comparability and repeatability of the test results.

[0051] As a preferred embodiment of the present invention, the evaluation of the coating performance includes coverage evaluation, thickness evaluation, and uniformity evaluation.

[0052] In a battery pack, one of the main functions of thermal conductive adhesive is to conduct heat, and the coverage rate directly affects the size of the area where heat can be effectively transferred. If the thermal conductive adhesive cannot completely cover the surface of the component that needs to dissipate heat, there will be blind spots in heat conduction, resulting in excessive local temperature, which will affect the performance and safety of the battery pack. By evaluating the coverage rate, it can be ensured that the thermal conductive adhesive fully covers the coated area of the battery pack box, thus ensuring that heat can be effectively conducted throughout the target area. Moreover, the coverage rate evaluation is also an intuitive reflection of the quality of the glue application process. If there are problems in the glue application process, such as uneven glue application or missed coating, it will directly lead to the failure of the coverage rate to meet the standard. By detecting and analyzing the coverage rate, problems existing in the glue application process can be discovered in a timely manner, and then the process can be optimized and improved to improve the quality and efficiency of glue application.

[0053] The thickness of the thermal conductive adhesive is closely related to its thermal conductivity. Different application scenarios of battery packs have specific requirements for the thickness of the thermal conductive adhesive. An appropriate thickness can ensure that the thermal conductive adhesive has good heat conduction ability. If the thickness is too thin, it may not be able to effectively conduct heat; while if the thickness is too thick, it may increase the thermal resistance and affect the heat dissipation effect. By evaluating the thickness, it can be ensured that the thickness of the thermal conductive adhesive meets the design requirements, thus ensuring the thermal conductivity of the battery pack. The thickness evaluation can also be used to detect the consistency and stability of the thermal conductive adhesive during the coating process. If the thickness of the thermal conductive adhesive varies greatly at different parts, it will lead to uneven temperature distribution inside the battery pack, affecting the performance and life of the battery. By accurately measuring and evaluating the thickness, problems of inconsistent thickness can be discovered and solved in a timely manner, ensuring the uniform and stable performance of the thermal conductive adhesive throughout the coated area.

[0054] The uniformity evaluation focuses on whether the thermal conductive adhesive is evenly distributed in the coated area. Uneven distribution of the thermal conductive adhesive will lead to uneven heat conduction, resulting in a temperature gradient inside the battery pack, affecting the performance and safety of the battery. For example, if the thermal conductive adhesive is too thick in some parts and too thin in other parts, it will cause different heat conduction speeds in these parts, resulting in local overheating or overcooling phenomena. By evaluating the uniformity, it can be ensured that the thermal conductive adhesive is evenly distributed throughout the coated area, achieving uniform heat conduction. The uniformity evaluation results can provide an important basis for optimizing the glue application process. If it is found that the uniformity does not meet the standard, it can be analyzed whether the problem is caused by the glue application equipment, glue application parameters or other factors, and then targeted improvements can be made. For example, adjusting the operating parameters of the glue application equipment, improving the glue application method, etc., to improve the uniformity of the thermal conductive adhesive and thus enhance the overall performance of the battery pack.

[0055] The present invention combines coverage evaluation, thickness evaluation, and uniformity evaluation, enabling a comprehensive assessment of the coating performance of thermal conductive adhesive from multiple perspectives. A single evaluation index may not accurately reflect the actual situation of thermal conductive adhesive coating, while comprehensive evaluation can provide a more comprehensive understanding of the coating effect of thermal conductive adhesive on the battery pack box body, discover potential problems, and provide a more reliable basis for optimizing the coating process of thermal conductive adhesive and improving the performance of the battery pack. Through the comprehensive evaluation and optimization of the coating performance of thermal conductive adhesive, the heat dissipation performance of the battery pack can be ensured to be more stable and reliable, reducing battery pack failures and performance degradation caused by thermal conductive adhesive coating problems, thereby improving the quality and reliability of the product and enhancing the competitiveness of the product in the market.

[0056] As a preferred embodiment of the present invention, the coverage evaluation specifically includes: after taking out the cured thermal conductive adhesive block, obtaining the theoretical coverage area S2 and the coverage area S1 on the side of the thermal conductive adhesive block close to the first isolation film, and calculating the coverage rate of the thermal conductive adhesive according to the calculation formula to obtain the coverage rate of the thermal conductive adhesive.

[0057] Among them, the acquisition of the theoretical coverage area specifically includes: using a measuring ruler to measure the length, width and other dimensions of the target area coated with thermal conductive adhesive on the battery pack box body, and calculating the area of the target area according to the geometric shape. For example, for a rectangular area, the area is equal to the length multiplied by the width; for an irregular area, it can be divided into multiple regular shapes for calculation. Or, obtain the design drawing of the battery pack box body and directly obtain the dimension and area data of the target area coated with thermal conductive adhesive from the drawing.

[0058] Using the ratio of the actual coverage area to the theoretical coverage area to determine the coverage rate can directly and accurately reflect the actual effect of glue application. If the coverage rate is close to 100%, it indicates that the thermal conductive adhesive basically completely covers the predetermined area and the glue application effect is good; if the coverage rate is low, it indicates that there are problems such as missed coating and insufficient glue volume during the glue application process, and the glue application process needs to be adjusted. Through this evaluation method, the deficiencies in the glue application process can be discovered in a timely manner, providing a strong basis for process optimization.

[0059] According to the design requirements and actual application scenarios of the battery pack, determine the qualified standard for the coverage rate of the thermal conductive adhesive. Generally speaking, the coverage rate of the thermal conductive adhesive should reach more than 90% to ensure good thermal conductivity, but the specific value can be adjusted according to different battery pack types and usage requirements. Compare the calculated coverage rate with the set standard. If the coverage rate reaches or exceeds the standard value, it is considered that the coverage rate of the thermal conductive adhesive meets the requirements; if the coverage rate is lower than the standard value, it indicates that there are problems with the coating of the thermal conductive adhesive, and the reasons need to be analyzed, such as improper glue application process and insufficient glue volume, and corresponding improvement measures need to be taken.

[0060] As a preferred embodiment of the present invention, the first isolation film is transparent, and a grid pattern is provided on the first isolation film; the acquisition of the coverage area S1 includes: observing the coincidence of the grid pattern on the first isolation film and the thermal conductive adhesive block, counting the number of grids covered by the thermal conductive adhesive, and then calculating the coverage area S1 on the side of the thermal conductive adhesive block close to the first isolation film according to the area of the grid.

[0061] The first isolation film being transparent enables the experimenter to clearly observe the distribution of the thermal conductive adhesive on the isolation film, including the boundary, shape of the thermal conductive adhesive, and whether there is any missed coating. This provides convenient conditions for accurately counting the number of grids covered by the thermal conductive adhesive subsequently. Compared with an opaque isolation film, the transparent characteristic greatly improves the intuitiveness and accuracy of observation.

[0062] The setting of the grid pattern provides a simple and effective method for measuring the coverage area of the thermal conductive adhesive. By counting the number of grids covered by the thermal conductive adhesive and combining with the known area of each grid, the coverage area of the thermal conductive adhesive can be calculated more precisely. This method converts the complex area measurement into relatively simple quantity counting and multiplication operations, reducing the measurement difficulty and error, especially suitable for irregularly shaped areas covered by the thermal conductive adhesive. The size of the grid should be selected according to the size of the thermal conductive adhesive block and the actual measurement accuracy requirements. For example, a grid board with a side length of 1 millimeter or 5 millimeters per grid can be selected.

[0063] By observing the coincidence of the grid pattern and the thermal conductive adhesive block, manually count the number of grids covered by the thermal conductive adhesive. For partially covered grids, an estimation can be made according to the coverage ratio. For example, a grid covered by more than half is counted as 1, and less than half is counted as 0.5, etc. Then calculate the coverage area of the thermal conductive adhesive according to the area of the grid.

[0064] Compared with the traditional method of using professional measuring tools (such as image acquisition equipment combined with complex image processing software) to measure the coverage area, the operation of observing the grid pattern and counting the number of grids is more simple and fast. After taking out the cured thermal conductive adhesive block, the experimenter can directly obtain relevant data through naked-eye observation and simple counting, greatly saving the measurement time and improving the test efficiency.

[0065] This method realizes the quantitative evaluation of the coverage area of the thermal conductive adhesive by counting the number of grids and calculating the area. The quantitative data can more accurately reflect the coverage of the thermal conductive adhesive, facilitating comparison with the theoretical coverage area, and thus obtaining a more accurate coverage rate. Compared with qualitative descriptions or estimations, this quantitative evaluation method is more scientific and reliable.

[0066] Due to the regularity and fixity of the grid pattern, different experimenters can obtain relatively consistent results when operating according to the same method. This ensures the repeatability of the experiment, making the experimental results obtained at different times and locations comparable, which is conducive to the long-term research and evaluation of the coating performance of the thermal conductive adhesive.

[0067] As a preferred embodiment of the present invention, the thickness evaluation specifically includes: after taking out the cured thermal conductive adhesive block, using a measuring tool to measure the measurement points at different positions on the thermal conductive adhesive block to obtain thickness measurement data; comparing the thickness measurement data with a preset standard thickness to evaluate whether the coating thickness of the thermal conductive adhesive meets the preset requirements.

[0068] By measuring the measurement points at different positions on the thermal conductive adhesive block, the present invention can more comprehensively understand the thickness distribution of the thermal conductive adhesive. Because in the actual glue coating process, due to the influence of factors such as glue coating process and equipment, the thickness of the thermal conductive adhesive may vary at different positions. The measurement method with multiple measurement points can avoid the one-sidedness of the results caused by only measuring a single position, making the obtained thickness measurement data more capable of reflecting the true thickness of the thermal conductive adhesive, thereby providing a reliable basis for accurately evaluating the coating thickness.

[0069] Comparing the measured thickness data with the preset standard thickness is an intuitive and effective evaluation method. The preset standard thickness is determined according to the design requirements of the battery pack and the performance characteristics of the thermal conductive adhesive. By comparison, it can be clearly judged whether the coating thickness of the thermal conductive adhesive meets the expectations. If the thickness measurement data is within the allowable error range of the preset standard thickness, it indicates that the coating thickness meets the requirements; otherwise, the glue coating process needs to be adjusted to ensure that the thickness of the thermal conductive adhesive can meet the performance requirements such as heat dissipation of the battery pack.

[0070] As a preferred embodiment of the present invention, the uniformity evaluation specifically includes: after taking out the cured thermal conductive adhesive block, using a measuring tool to measure the measurement points at different positions on the thermal conductive adhesive block to obtain thickness measurement data; comparing the thickness measurement data of each measurement point with a preset thickness range to evaluate whether the coating uniformity of the thermal conductive adhesive meets the preset requirements.

[0071] Similar to the thickness evaluation, measuring the measurement points at different positions on the thermal conductive adhesive block helps to comprehensively understand the thickness distribution of the thermal conductive adhesive. Because the uniformity focuses on the thickness consistency of the thermal conductive adhesive in the entire coating area, by obtaining data from multiple measurement points, it can be more accurately judged whether the thickness is uniform. A single measurement point cannot reflect the overall uniformity, while multiple measurement points can cover different regions, making the evaluation result more representative.

[0072] Comparing the thickness measurement data of each measurement point with a preset thickness range is an effective way to judge the uniformity. The preset thickness range is determined according to the performance requirements and process standards of the product. As long as the thickness data of the measurement points are within this range, it is considered that the coating of the thermal conductive adhesive is uniform to a certain extent. This comparison method can quantify the evaluation of uniformity, avoid the uncertainty of subjective judgment, and make the evaluation results more objective and scientific.

[0073] In one embodiment, as shown in Figure 2 , the present invention provides a coating performance test device for a battery pack thermal conductive adhesive. The test device 10 includes a battery pack box body 20, a first isolation film 30, a second isolation film 40, and a pressing component 40. The battery pack box body 20 includes a thermal conductive adhesive coating area. The first isolation film 30 is laid on the thermal conductive adhesive coating area of the battery pack box body 20 for isolating the thermal conductive adhesive block 60 and the battery pack box body 20. The second isolation film 40 is laid on the surface of the thermal conductive adhesive after the glue coating is completed for isolating the thermal conductive adhesive block 60 and the pressing component 50 after the thermal conductive adhesive is cured. The pressing component 50 is used to simulate the battery pack module.

[0074] As shown in Figure 3 , after the thermal conductive adhesive is cured, the first isolation film 30 is used to isolate the thermal conductive adhesive block 60 and the battery pack box body 20, and the second isolation film 40 is used to isolate the thermal conductive adhesive block 60 and the pressing component 50, thereby avoiding the direct adhesion of the thermal conductive adhesive block 60 to the battery pack box body 20 and the pressing component 50 of the test sample, so that the battery pack box body 20 and the pressing component 50 can be reused. With such a setting, the test cost is reduced. When the coating performance of the battery pack thermal conductive adhesive does not meet the preset requirements, there is no need to remake the test sample separately, improving the test efficiency. And by introducing the use of the isolation film, after the test is over, the cleaning work changes from laboriously cleaning the thermal conductive adhesive on the sample to easily removing the pressing component 50 and the cured thermal conductive adhesive block 60, greatly reducing the work burden of the test personnel.

[0075] As a preferred embodiment of the present invention, the pressing component 50 includes a plurality of cell components arranged at intervals; each cell component includes an end plate 51, a cell monomer 52, and a simulated cell 53. A plurality of cell monomers 52 are stacked and fixed between two end plates 51 along their thickness directions. The simulated cell 53 is arranged between two stacked cell monomers 52, and a connection part adapted to a disassembly tool is provided on the simulated cell 53.

[0076] The pressure - applying component 50 is composed of several cell components arranged at intervals. Inside the cell component, multiple cell monomers 52 are stacked and fixed in the thickness direction between two end plates 51. This structure well simulates the arrangement and fixing method of cells in an actual battery pack module. In a real battery pack module, cells are also stacked together in a similar way. Therefore, the pressure - applying component 50 can more realistically simulate the pressure effect of the battery pack module on the thermal conductive adhesive, making the test environment closer to the actual use scenario, thereby improving the reliability and effectiveness of the test results, and enabling R & D personnel to more accurately evaluate the coating performance of the thermal conductive adhesive under actual working conditions.

[0077] Since the simulated cell 53 is arranged between two stacked cell monomers 52, the authenticity of the simulation is further enhanced. The presence of the simulated cell 53 can supplement certain specific test requirements without affecting the overall structure and pressure application. For example, in some tests, it may be necessary to simulate different cell sizes, shapes, or weight distributions, etc. The simulated cell 53 can be designed and adjusted according to specific requirements to meet diverse test conditions.

[0078] Since the simulated cell 53 is provided with a connection part adapted to a disassembly tool, this design greatly facilitates the disassembly operation after the test. After the thermal conductive adhesive is cured, the test personnel can easily remove the simulated cell 53 from the cell component through the connection part using the corresponding disassembly tool, and then more conveniently disassemble and clean the entire pressure - applying component 50. Compared with the design without such a connection part, using the connection part can save a large amount of disassembly time and effort, improve the test efficiency, and at the same time reduce the damage to the pressure - applying component caused by forced disassembly, extending its service life.

[0079] The pressure - applying component 50 adopts this modular structure with multiple cell components arranged at intervals. Each cell component is relatively independent and can be operated separately during disassembly and assembly. When it is necessary to inspect, repair, or replace a certain cell component, it is not necessary to carry out large - scale disassembly of the entire pressure - applying component, and only the corresponding cell component needs to be processed, which makes the operation more flexible and convenient.

[0080] The simulated cell 53 can be designed and replaced according to different test requirements, making the pressure - applying component 50 highly customizable. R & D personnel can replace the appropriate simulated cell 53 according to specific test purposes, such as testing the performance of different thermal conductive adhesives under different cell pressure conditions, or studying the influence of different cell arrangement methods on the coating effect of the thermal conductive adhesive, etc., so as to quickly adjust the test conditions and conduct diverse tests.

[0081] The design of several spaced-apart battery cell assemblies also enables the pressure-applying assembly to have a certain degree of scalability. If it is necessary to increase or decrease the pressure magnitude of the pressure-applying assembly 5 or simulate a more complex battery pack module structure, it can be achieved by increasing or decreasing the number of battery cell assemblies. This scalability enables the pressure-applying assembly 50 to adapt to test requirements of different scales and complexities, improving its versatility and applicability.

[0082] The above embodiments are only preferred embodiments cited to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are within the protection scope of the present invention.

Claims

1. A method for testing the coating performance of thermal conductive adhesive for battery packs, characterized in that: include: Laying a first isolation film on the thermally conductive adhesive coating area of ​​the battery pack body; Applying glue to the battery pack body according to a preset amount of thermal conductive glue on the surface of the first isolation film; After the glue coating is completed, a second isolation film is laid on the surface of the thermally conductive glue, and the pressure-applying assembly is fixedly assembled to the battery pack box until the thermally conductive glue is completely cured; After the thermal conductive adhesive is cured, first remove the pressure-applying component, and then remove the cured thermal conductive adhesive block to evaluate the coating performance.

2. The coating performance test method of the thermal conductive adhesive for battery pack according to claim 1, characterized in that: The materials of the first isolation film and the second isolation film are independently polyethylene, polypropylene, polyvinyl chloride, and polyvinylidene chloride; And / or, the thickness of the first isolation film and the second isolation film are independently 0.02 mm to 0.08 mm.

3. The coating performance test method of the thermal conductive adhesive for battery pack according to claim 2, characterized in that: The calculation formula for the preset amount of thermal conductive adhesive is: Where Q is the preset amount of thermal conductive adhesive, A is the area of ​​thermal conductive adhesive coating, and D is the preset thickness of the thermal conductive adhesive after curing. is the correction factor.

4. The coating performance test method of the thermal conductive adhesive for battery pack according to claim 1, characterized in that: The coating performance evaluation includes coverage evaluation, thickness evaluation and uniformity evaluation.

5. The coating performance test method of the thermal conductive adhesive for battery pack according to claim 4, characterized in that: The coverage evaluation specifically includes: after taking out the cured thermal conductive adhesive block, obtaining the theoretical coverage area S2 and the coverage area S1 of the thermal conductive adhesive block close to the first isolation film, and calculating according to the formula The coverage of thermal conductive adhesive is calculated.

6. The coating performance test method of the thermal conductive adhesive for battery pack according to claim 5, characterized in that: The first isolation film is transparent, and a grid pattern is provided on the first isolation film; The acquisition of the coverage area S1 includes: observing the overlap between the grid pattern on the first isolation film and the thermally conductive adhesive block, counting the number of grids covered by the thermally conductive adhesive, and then calculating the coverage area S1 of the thermally conductive adhesive block close to the first isolation film based on the area of ​​the grids.

7. The coating performance test method of the thermal conductive adhesive for battery pack according to claim 4, characterized in that: The thickness evaluation specifically includes: after taking out the cured thermal conductive adhesive block, using a measuring tool to measure the measuring points at different positions on the thermal conductive adhesive block to obtain thickness measurement data; comparing the thickness measurement data with the preset standard thickness to evaluate whether the coating thickness of the thermal conductive adhesive meets the preset requirements.

8. The coating performance test method of the thermal conductive adhesive for battery pack according to claim 4, characterized in that: The uniformity evaluation specifically includes: After taking out the cured thermal conductive adhesive block, use a measuring tool to measure the measuring points at different positions on the thermal conductive adhesive block to obtain thickness measurement data; Compare the thickness measurement data of each measuring point with the preset thickness range to evaluate whether the coating uniformity of the thermal conductive adhesive meets the preset requirements.

9. A coating performance test device for a battery pack thermal conductive adhesive, characterized in that: include: Battery pack case, including thermally conductive adhesive coating area; A first isolation film is laid on the thermally conductive adhesive coating area of ​​the battery pack body to isolate the thermally conductive adhesive block from the battery pack body; A second isolation film is laid on the surface of the thermally conductive adhesive after the adhesive coating is completed, so as to isolate the thermally conductive adhesive block and the pressure-applying component; Pressure assembly used to simulate battery pack modules.

10. The coating performance test device of the thermal conductive adhesive for battery pack according to claim 9, characterized in that: The pressure-applying assembly includes a plurality of battery cell assemblies arranged at intervals; The battery cell assembly includes an end plate, a battery cell and a simulated battery cell. A plurality of battery cells are stacked and fixed between two end plates along their thickness direction. The simulated battery cell is arranged between two stacked battery cells, and a connection portion compatible with a disassembly tool is provided on the simulated battery cell.

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