Current collector coating thickness detection device and detection method

Abstract

The present application discloses a device and method for detecting the thickness of a current collector coating. The device and method for detecting the thickness of a current collector coating include a main body, a conveying mechanism, and a detecting mechanism. A first chamber is provided on the main body; the conveying mechanism is provided on the main body and is located outside the first chamber, and the conveying mechanism is at least used to convey a heat-conducting medium to the first chamber; the detecting mechanism is provided in the first chamber, and the detecting mechanism includes a first electrode assembly and a first temperature detecting element, the first electrode assembly is used to energize the current collector to be detected, and the first temperature detecting element is used to detect the temperature of the heat-conducting medium in the first chamber. The device and method for detecting the thickness of a current collector coating do not require cutting and slicing the current collector to be detected, and can quickly detect the thickness of the coating on the current collector.

Description

Technical Field

[0001] The present application relates to the technical field of current collector detection, and in particular to a current collector coating thickness detection device and detection method. Background Art

[0002] The composite current collector is a composite conductive film with copper or aluminum plated on both sides of a polymer base film. Compared with traditional current collectors, it can improve the safety and energy density of batteries when used in lithium batteries.

[0003] The coating thickness of composite current collectors is very thin, typically 1 to 4 μm, making it difficult to measure. Existing techniques typically use electron microscopy to measure composite current collector coating thickness. However, electron microscopy requires cutting the product to be tested into slices, which is cumbersome, time-consuming, and slow. Summary of the Invention

[0004] The main purpose of the present application is to provide a current collector coating thickness detection device and detection method, which do not require cutting and slicing the current collector to be tested, and can quickly detect the thickness of the coating on the current collector.

[0005] According to one aspect of the present application, a device for detecting the thickness of a current collector coating is provided, comprising:

[0006] a main body, wherein a first chamber is provided on the main body;

[0007] a conveying mechanism, the conveying mechanism being provided on the main body and located outside the first chamber, the conveying mechanism being at least used for conveying a heat-conducting medium to the first chamber;

[0008] A detection mechanism is arranged in the first chamber, and the detection mechanism includes a first electrode assembly and a first temperature detection element. The first electrode assembly is used to energize the collector to be detected, and the first temperature detection element is used to detect the temperature of the heat-conducting medium in the first chamber.

[0009] Furthermore, a first heat insulation layer is provided on the inner wall surface of the first chamber.

[0010] Furthermore, a second chamber is provided on the main body, and the second chamber has the same shape as the first chamber. The conveying mechanism is used to convey the heat-conducting medium to the second chamber; the current collector coating thickness detection device also includes:

[0011] A comparison mechanism is arranged in the second chamber, and the comparison mechanism includes a second electrode assembly and a second temperature detection element. The second electrode assembly is used to energize a conductive element with a known resistance, and the second temperature detection element is used to detect the temperature of the heat-conducting medium in the second chamber.

[0012] Furthermore, a second heat insulation layer is provided on the inner wall surface of the second chamber.

[0013] Furthermore, the first electrode assembly and the second electrode assembly each include a positive electrode and a negative electrode, the positive electrode and the negative electrode are spaced apart, and a detachable conductive clip is provided on the positive electrode and the negative electrode.

[0014] Furthermore, the conveying mechanism includes:

[0015] a liquid storage container, the liquid storage container being used to store the heat-conducting medium;

[0016] an infusion tube, the infusion tube comprising a first infusion tube and a second infusion tube, the first infusion tube having two ends communicating with the first chamber and the liquid storage container, respectively, and the second infusion tube having two ends communicating with the second chamber and the liquid storage container, respectively;

[0017] The liquid return pipe includes a first liquid return pipe and a second liquid return pipe, the two ends of the first liquid return pipe are respectively connected to the bottom of the first chamber and the liquid storage container, and the two ends of the second liquid return pipe are respectively connected to the second chamber and the liquid storage container.

[0018] Furthermore, the current collector coating thickness detection device further includes:

[0019] A temperature control system is provided on the main body for controlling the temperature of the heat-conducting medium in the liquid storage container.

[0020] Furthermore, a stirrer is provided in both the first chamber and the second chamber.

[0021] Furthermore, liquid level detection elements are provided in both the first chamber and the second chamber.

[0022] On the other hand, the present application also provides a current collector thickness detection method, which is performed using the above-mentioned current collector coating thickness detection device, and the current collector coating thickness detection method includes:

[0023] Step S1: placing a current collector sample to be tested into the first chamber, introducing a heat-conducting medium into the first chamber using the conveying mechanism, and then passing an electric current through the current collector using the first electrode assembly;

[0024] Step S2: Detecting the temperature change of the heat-conducting medium in the first chamber using the first temperature detection element;

[0025] Step S3: Calculate the heat Q generated when the current collector is energized based on the detection result of the first temperature detection element, calculate the resistance R of the conductive layer of the current collector based on Q, and calculate the thickness h of the conductive layer of the current collector based on the resistance R.

[0026] Furthermore, in the step S2, the temperature of the heat-conducting medium in the first chamber is detected twice using the first temperature detection element;

[0027] In step S3, the temperature difference ΔT between the two detections of the heat conducting medium is calculated, and the heat Q generated when the current collector is energized is calculated using the formula Q=cmΔT. 2 The resistance R of the conductive layer of the current collector is calculated by Rt, wherein c is the specific heat capacity of the heat-conducting medium, m is the mass of the heat-conducting medium in the first chamber, I is the current flowing through the first electrode assembly, and t is the time when the first electrode assembly is energized.

[0028] Furthermore, step S1 further includes: placing a conductive element of known resistance into a second chamber of the current collector coating thickness detection device, and using the conveying mechanism to pass a heat-conducting medium of the same mass as that of the first chamber into the second chamber, and then using the second electrode assembly of the current collector coating thickness detection device to pass current through the conductive element, so that the first electrode assembly and the second electrode assembly are supplied with the same current;

[0029] In step S2, the temperature of the heat-conducting medium in the first chamber is detected by the first temperature detection element until the temperature of the heat-conducting medium reaches Tstop, and the power-on time t1 of the first electrode assembly is recorded; the temperature of the heat-conducting medium in the second chamber is detected by the second temperature detection element of the current collector coating thickness detection device until the temperature of the heat-conducting medium reaches Tstop, and the power-on time t2 of the second electrode assembly is recorded;

[0030] In step S3, based on the principle that the temperature changes in the first chamber and the second chamber are the same, the resistance R of the conductive layer of the current collector is calculated using the formula R=R1t2 / t1, where R1 is the resistance of the conductive element.

[0031] Furthermore, the step S1 further includes: placing a conductive element of known resistance into the second chamber of the current collector coating thickness detection device, and using the conveying mechanism to pass the heat conductive medium of the same mass as that of the first chamber into the second chamber, and then using the second electrode assembly of the current collector coating thickness detection device to pass current through the conductive element;

[0032] In step S2, the temperatures in the first chamber and the second chamber are monitored respectively using the first temperature detection element and the second temperature detection element of the current collector coating thickness detection device, and the supply currents to the first electrode assembly and the second electrode assembly are adjusted so that the temperature rise curve in the first chamber is the same as the temperature rise curve in the second chamber;

[0033] In step S3, the square of the current in step S2 is integrated, and based on the principle that the temperature changes of the heat transfer medium in the first chamber and the second chamber are the same in the same time, the formula The resistance R of the conductive layer of the current collector is calculated, where R1 is the resistance of the conductive element, I1 is the power supply current of the second electrode assembly, I2 is the power supply current of the first electrode assembly, and t is the power supply time of the first electrode assembly and the second electrode assembly.

[0034] Furthermore, in step S3, the thickness h of the conductive layer of the current collector is calculated using the formula R=ρL / S and the formula S=h*d, wherein ρ is the resistivity of the conductive layer of the current collector, S is the cross-sectional area of ​​the conductive layer, d is the width of the conductive layer of the current collector, and L is the length of the current collector.

[0035] In the present application, a main body, a conveying mechanism, and a detection mechanism are provided on a current collector coating thickness detection device. A heat-conducting medium is conveyed to the first chamber on the main body by the conveying mechanism, and the current collector placed in the first chamber is powered by a first electrode assembly. At the same time, the temperature of the heat-conducting medium is detected by a first temperature detection element. Combined with a specific physical calculation formula, the thickness h of the conductive layer on the current collector can be converted. Compared to the prior art method of cutting and slicing the product and observing and measuring with an electron microscope, the current collector coating thickness detection device in the present application can more quickly detect and convert the thickness h of the conductive layer on the current collector, which saves time and has higher detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0037] Figure 1 This is a schematic structural diagram of a current collector coating thickness detection device disclosed in an embodiment of the present application;

[0038] Figure 2 A side view of a current collector coating thickness detection device disclosed in an embodiment of the present application;

[0039] Figure 3 This is a flow chart of the current collector coating thickness detection method disclosed in an embodiment of the present application.

[0040] The above drawings include the following reference numerals:

[0041] 10. Main body; 11. First chamber; 12. Second chamber; 20. Conveying mechanism; 21. Liquid storage container; 22. First infusion tube; 23. Second infusion tube; 24. First return tube; 25. Second return tube; 30. Detection mechanism; 31. First electrode assembly; 32. First temperature detection element; 40. First thermal insulation layer; 50. Comparison mechanism; 51. Second electrode assembly; 52. Second temperature detection element; 60. Conductive element; 70. Second thermal insulation layer; 80. Temperature control system; 90. Current collector; 100. Agitator. DETAILED DESCRIPTION

[0042] 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 application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] 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.

[0044] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary, not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0045] See also Figures 1 to 2 As shown, according to an embodiment of the present application, a device for detecting the thickness of a current collector coating is provided. The device for detecting the thickness of a current collector coating includes a main body 10 , a conveying mechanism 20 and a detecting mechanism 30 .

[0046] In which, a first chamber 11 is provided on the main body 10; the conveying mechanism 20 is provided on the main body 10 and is located outside the first chamber 11, and the conveying mechanism 20 is at least used to convey the heat-conducting medium to the first chamber 11; the detection mechanism 30 is provided in the first chamber 11, and the detection mechanism 30 includes a first electrode assembly 31 and a first temperature detection element 32, the first electrode assembly 31 is used to energize the collector 90 to be detected, and the first temperature detection element 32 is used to detect the temperature of the heat-conducting medium in the first chamber 11.

[0047] When the current collector coating thickness detection device of this embodiment is used to detect the thickness of the current collector 90, the current collector 90 is first placed in the first chamber 11 and electrically connected to the first electrode assembly 31. Then, the delivery mechanism 20 is used to deliver a heat-conducting medium to the first chamber 11, and then the first electrode assembly 31 is turned on to supply power to the current collector 90. The temperature of the heat-conducting medium is then detected by the first temperature detection element 32, and the thickness of the conductive layer on the current collector 90 is calculated based on the detection result.

[0048] When actually detecting and calculating the thickness of the conductive layer of the current collector 90, different parameter changes can be controlled to detect the thickness of the conductive layer of the current collector 90. For example, when actually detecting the thickness of the conductive layer of the current collector 90, when the first electrode assembly 31 is used to power the current collector 90, the first temperature detection element 32 can be used to detect the heat-conducting medium in the first chamber 11 twice in succession, and the temperature values ​​of the two times can be recorded respectively. Thereafter, the heat released by the current collector 90 can be calculated using this temperature value, that is, Q=cmΔT. In this formula, c is the specific heat capacity of the heat-conducting medium. When the heat-conducting medium is constant, c is a known quantity, m is the mass of the heat-conducting medium in the first chamber 11, which can be weighed, and ΔT is the difference in temperature between the two measurements by the first temperature detection element 32, which can be directly calculated. Then, according to the formula Q=I 2 The resistance of the conductive layer on the current collector 90 can be calculated by calculating Rt, where I is the current supplied to the current collector 90 by the first electrode assembly 31, R is the resistance of the conductive layer on the current collector 90, and t is the power supply time of the first electrode assembly 31. Finally, the thickness h of the conductive layer of the current collector 90 can be calculated using the formula R = ρL / S and the formula S = h*d, where ρ is the resistivity of the conductive layer of the current collector 90, S is the cross-sectional area of ​​the conductive layer, d is the width of the conductive layer of the current collector 90, which can be measured, and L is the length of the conductive layer of the current collector 90, which can be measured. Since ρ is known, the thickness h of the conductive layer can be calculated.

[0049] That is, this embodiment provides a main body 10, a conveying mechanism 20, and a detection mechanism 30 on the current collector coating thickness detection device. The conveying mechanism 20 delivers a heat-conducting medium to the first chamber 11 on the main body 10, and the first electrode assembly 31 is used to power the current collector 90 placed in the first chamber 11. At the same time, the first temperature detection element 32 is used to detect the temperature of the heat-conducting medium. Combined with a specific physical calculation formula, the thickness h of the conductive layer on the current collector 90 can be converted. Compared to the prior art method that requires cutting and slicing the product and using an electron microscope for observation and measurement, the current collector coating thickness detection device in this embodiment can more quickly detect and convert the thickness h of the conductive layer on the current collector 90, saving time and improving detection efficiency.

[0050] Combine Figure 1 and Figure 2As shown, the main body 10 in this embodiment can be a box structure, and the first chamber 11 is preferably a closed cavity to prevent the external environment from affecting the heat-conducting medium or the current collector 90 in the first chamber 11. Furthermore, in order to improve the detection accuracy of the detection device, a first thermal insulation layer 40 is provided on the inner wall surface of the first chamber 11 in this embodiment. The first thermal insulation layer 40 can be, for example, a structure such as thermal insulation foam or thermal insulation foam. Through the action of the first thermal insulation layer 40, the heat-conducting medium in the first chamber 11 can be isolated from the external environment, avoiding heat exchange between the heat-conducting medium and the external environment, and improving the detection accuracy of the current collector coating thickness detection device in this embodiment.

[0051] In order to further eliminate the influence of the external environment on the detection and calculation results of the thickness of the conductive layer of the current collector 90, a second chamber 12 is further provided on the main body 10 of the current collector coating thickness detection device in this embodiment. The second chamber 12 is consistent in shape with the first chamber 11, and the conveying mechanism 20 can simultaneously convey the heat-conducting medium to the first chamber 11 and the second chamber 12. The current collector coating thickness detection device also includes a comparison mechanism 50, which is arranged in the second chamber 12. The comparison mechanism 50 includes a second electrode assembly 51 and a second temperature detection element 52. The second electrode assembly 51 is used to energize the conductive element 60 of known resistance, and the second temperature detection element 52 is used to detect the temperature of the heat-conducting medium in the second chamber 12. Optionally, the conductive element 60 in this embodiment can be a conductive wire, a conductive sheet, or other structures.

[0052] In this embodiment, the second chamber 12 is provided, and the comparison mechanism 50 is correspondingly provided in the second chamber 12 to energize and detect the conductive element 60 of known resistance, thereby eliminating detection errors caused by environmental influences.

[0053] Specifically, by providing the comparison mechanism 50 and the second chamber 12 to detect different physical quantities, different physical principles can be used to measure and convert the thickness of the conductive layer on the current collector 90 .

[0054] For example:

[0055] Solution 1 (measuring time):

[0056] In this solution, an identical environment can be established to replace the current collector 90 with a conductive element 60 of known resistance for comparative testing. The current, heat-conducting medium, and mass of the heat-conducting medium for the comparative test are the same as those in the first chamber 11. The resistance of the conductive element 60 is R1, and the resistance of the current collector 90 to be tested is R. At this time, the test can be carried out in the second chamber 12 for a period of time t2, and the temperature of the heat-conducting medium in the second chamber 12 reaches a certain temperature. Then, the time t1 when the temperature of the heat-conducting medium in the second chamber 12 reaches the same temperature as the first chamber 11 is tested. Since the temperatures of the first chamber 11 and the second chamber are the same, Q1=Q2, and I is equal, then R=R1t2 / t1. R is calculated from this, and then the thickness h of the conductive layer of the current collector 90 is calculated using the formula R=ρL / S and the formula S=h*d. It can be seen that this embodiment can reduce the calculation steps by setting up a comparative test, eliminate the influence of the environment, and obtain more accurate results.

[0057] Option 2 (adjusting current):

[0058] An identical environment is established, and the current collector 90 is replaced with a conductive element 60 of known resistance for comparative testing. The heat-conducting medium and the heat-conducting medium are of the same quality, the resistance of the conductive element 60 is R1, and the resistance of the current collector 90 to be tested is R. The first chamber 11 and the second chamber 12 are tested simultaneously (the first chamber 11 is started for more than ten seconds and then the reference chamber is started. In this way, the heating current of the reference chamber can be adjusted by analyzing the temperature rise of the test chamber within this time difference). The current of the second chamber 12 is dynamically adjusted and recorded so that the temperature rise curve of the second chamber 12 is consistent with the temperature rise curve of the first chamber 11, so that the temperatures of the first chamber 11 and the second chamber 12 are the same after a certain period of time. Then, the square of the current in this process, I1, is calculated. 2 Integrating, the heat Q of the two environments is the same, that is, we can get Thus, R can be calculated, and then the thickness h of the conductive layer of the current collector 90 can be calculated using the formula R=ρL / S and the formula S=h*d. Similarly, this embodiment can eliminate the influence of the environment by setting up a comparative test, and the obtained results are more accurate.

[0059] Furthermore, a second thermal insulation layer 70 is provided on the inner wall of the second chamber 12. This second thermal insulation layer 70 may be, for example, a structure such as thermal insulation foam. This second thermal insulation layer 70 isolates the heat-conducting medium in the second chamber 12 from the external environment, preventing heat exchange between the heat-conducting medium and the external environment, thereby improving the detection accuracy of the current collector coating thickness detection device in this embodiment.

[0060] Furthermore, the first electrode assembly 31 and the second electrode assembly 51 in this embodiment both include a positive electrode and a negative electrode, the positive electrode and the negative electrode are spaced apart, and a detachable conductive clip (not shown in the figure) is provided on the positive electrode and the negative electrode. During actual testing, the two ends of the current collector 90 and the conductive element 60 are electrically connected to the positive electrode and the negative electrode respectively through the conductive clip. The structure is simple and the disassembly and assembly are more convenient, which can further improve the detection efficiency of the current collector coating thickness detection device in this embodiment. In the present application, the conductive clip is detachable, the conductive clip can be replaced, and the single-sided overcurrent or double-sided overcurrent test of the current collector 90 can also be performed. Optionally, the conductive clip in this embodiment can be a metal clip that can clamp the current collector 90 and the conductive element 60, etc. As long as it is other deformation methods under the conception of this application, it is within the scope of protection of this application.

[0061] Furthermore, in this embodiment, a stirrer 100 is provided in both the first chamber 11 and the second chamber 12. By providing the stirrer 100 in the first chamber 11 and the second chamber 12, this embodiment can quickly stir and mix the heat-conducting medium in the first chamber 11 and the second chamber 12, thereby ensuring that the temperature of the heat-conducting medium is balanced at all locations, thereby ensuring the accuracy of the detection results of the first temperature detection element 32 and the second temperature detection element 52, and ultimately more accurately converting the thickness of the conductive layer on the current collector 90 in this embodiment.

[0062] Optionally, the first temperature detection element 32 and the second temperature detection element 52 both include thermocouples. Of course, in other embodiments of the present application, the first temperature detection element 32 and the second temperature detection element 52 can also be thermometers, etc. As long as they are other variations based on the conception of the present application, they are within the scope of protection of the present application.

[0063] Furthermore, in this embodiment, liquid level detection elements are provided in the first chamber 11 and the second chamber 12. The liquid level detection elements can be structures such as liquid level floats. Through the action of the liquid level detection elements, the liquid levels in the first chamber 11 and the second chamber 12 can be detected, and the liquid levels in the first chamber 11 and the second chamber 12 can be kept the same, which is convenient for testing and comparative testing of the current collector 90 and the conductive element 60.

[0064] Combine Figure 1 As shown, the delivery mechanism 20 in this embodiment includes a liquid storage container 21, a liquid infusion tube and a liquid return tube.

[0065] Among them, the liquid storage container 21 is used to store the heat-conducting medium; the infusion pipe includes a first infusion pipe 22 and a second infusion pipe 23, the two ends of the first infusion pipe 22 are respectively connected to the first chamber 11 and the liquid storage container 21, and the two ends of the second infusion pipe 23 are respectively connected to the second chamber 12 and the liquid storage container 21; the return pipe includes a first return pipe 24 and a second return pipe 25, the two ends of the first return pipe 24 are respectively connected to the bottom of the first chamber 11 and the liquid storage container 21, and the two ends of the second return pipe 25 are respectively connected to the second chamber 12 and the liquid storage container 21.

[0066] During actual use, a liquid pump structure can be set on the first infusion tube 22, the second infusion tube 23, the first return tube 24 and the second return tube 25. Through the above-mentioned liquid storage container 21, infusion tube, return tube and liquid pump structure, the heat-conducting medium can be transported to the first chamber 11 and the second chamber 12 when testing is required, and after the test is completed, the heat-conducting medium in the first chamber 11 and the second chamber 12 is drawn back to the liquid storage container 21, and the heat-conducting medium temperature returns to the initial temperature before entering the first chamber 11 and the second chamber 12 for the next test. The structure is simple and easy to use.

[0067] Furthermore, the current collector coating thickness detection device also includes a temperature control system 80, which is arranged on the main body 10 to control the temperature of the heat-conducting medium in the liquid storage container 21. After each test, the heated heat-conducting liquid returns to the liquid storage container 21, and the temperature control system 80 cools down the liquid in the liquid storage tank so that the temperature of the heat-conducting medium flowing into the first chamber 11 and the second chamber 12 during each test is constant. Optionally, the temperature control system in this embodiment includes a cooling device, a controller and a detection element. The cooling device is used to cool the heat-conducting medium in the liquid storage container 21. The detection element can be a structure such as a temperature sensor. The temperature sensor is used to detect the temperature of the heat-conducting medium in the liquid storage container 21. The controller is electrically connected to the detection element and controls the working condition of the cooling device. Specifically, when the detection element detects that the temperature of the heat-conducting medium in the liquid storage container 21 reaches a predetermined value, the controller controls the cooling device to stop cooling to ensure that the temperature in the liquid storage container 21 remains constant. In this embodiment, the cooling device may be a heat exchanger or other structure. As long as it is other variations based on the concept of this application, it is within the protection scope of this application.

[0068] The thermally conductive medium in this embodiment is a medium with a low specific heat capacity that does not react with the current collector, such as oil, making it easier to measure thermal changes in the environment. In actual design, the current collector thickness detection device is also equipped with a calculation module, such as a computer. This calculation module can calculate the physical parameters mentioned above, further improving the detection efficiency of the current collector thickness detection device in this embodiment.

[0069] Combine Figures 1 to 3 According to another aspect of the present invention, a method for detecting the thickness of a current collector is provided. This method is performed using the current collector coating thickness detection device described above. In this embodiment, the method for detecting the thickness of the current collector coating mainly includes three steps, which are described in detail below.

[0070] When actually testing the thickness of the coating layer, i.e., the conductive layer, on the current collector 90, the testing can be performed based on different physical principles. This application lists three different methods for testing, as follows:

[0071] Method 1: Measuring temperature

[0072] Step S1 : placing a current collector 90 sample into the first chamber 11 , and using the conveying mechanism 20 to introduce a heat-conducting medium into the first chamber 11 , and then using the first electrode assembly 31 to pass current through the current collector 90 .

[0073] Step S2: Using the first temperature detection element 32 to detect the temperature change of the heat-conducting medium in the first chamber 11. During the test, the first temperature detection element 32 is used to detect the temperature of the heat-conducting medium in the first chamber 11 twice.

[0074] Step S3: Calculate the heat Q generated when the current collector 90 is energized based on the detection result of the first temperature detection element 32 , calculate the resistance R of the conductive layer of the current collector 90 based on Q, and calculate the thickness h of the conductive layer of the current collector 90 based on the resistance R.

[0075] Specifically, in this step, the temperature difference ΔT of the heat conducting medium is calculated based on the detection results of the first temperature detection element 32 twice, and the heat Q generated when the current collector 90 is energized is calculated using the formula Q=cmΔT. 2 The resistance R of the conductive layer of the current collector 90 is calculated using Rt, where c is the specific heat capacity of the thermally conductive medium (which is known when the thermally conductive medium is constant), m is the mass of the thermally conductive medium in the first chamber 11 (which can be weighed), I is the current flowing through the first electrode assembly 31 (which can be measured), and t is the time the power is applied to the first electrode assembly 31. Finally, the thickness h of the conductive layer of the current collector 90 is calculated using the formulas R = ρL / S and S = h*d, where ρ is the resistivity of the conductive layer of the current collector 90, S is the cross-sectional area of ​​the conductive layer, d is the width of the conductive layer of the current collector 90 (which can be measured), and L is the length of the conductive layer of the current collector 90 (which can be measured). Since ρ is known, the thickness h of the conductive layer can be calculated.

[0076] Method 2: Measuring time

[0077] This method is basically the same as method 1, except that: step S1 in this embodiment also includes: placing a conductive element 60 with known resistance into the second chamber 12 of the current collector coating thickness detection device, and using the conveying mechanism 20 to pass a heat conductive medium of the same mass as that of the first chamber 11 into the second chamber 12, and then using the second electrode assembly 51 of the current collector coating thickness detection device to pass current through the conductive element 60, and making the power supply current of the first electrode assembly 31 and the second electrode assembly 51 the same.

[0078] In step S2, the temperature of the heat-conducting medium in the first chamber 11 is detected by the first temperature detection element 32 until the temperature of the heat-conducting medium reaches Tstop, and the power-on time t1 of the first electrode assembly 31 is recorded; the temperature of the heat-conducting medium in the second chamber 12 is detected by the second temperature detection element 52 until the temperature of the heat-conducting medium reaches Tstop, and the power-on time t2 of the second electrode assembly 51 is recorded.

[0079] In step S3, based on the principle that the temperature changes in first chamber 11 and second chamber 12 are identical, i.e., Q1=Q2, the resistance R of the conductive layer of current collector 90 is calculated using the formula R=R1t2 / t1, where R1 is the resistance of conductive element 60. Finally, the thickness h of the conductive layer of current collector 90 is calculated using the formulas R=ρL / S and S=h*d, where ρ is the resistivity of the conductive layer of current collector 90, S is the cross-sectional area of ​​the conductive layer, d is the width of the conductive layer of current collector 90, which can be measured, and L is the length of the conductive layer of current collector 90, which can be measured. Since ρ is known, the thickness h of the conductive layer can be calculated.

[0080] Method 3: Adjusting Current This method is substantially the same as Method 1, except that step S1 of this method further includes: placing a conductive element 60 of known resistance into the second chamber 12 of the current collector coating thickness detection device, and using the conveying mechanism 20 to pass a heat-conducting medium of the same mass as that of the first chamber 11 into the second chamber 12, and then passing a current through the conductive element 60 using the second electrode assembly 51 of the current collector coating thickness detection device;

[0081] In step S2, the temperatures in the first chamber 11 and the second chamber 12 are monitored using the first temperature detection element 32 and the second temperature detection element 52, respectively, and the supply currents of the first electrode assembly 31 and the second electrode assembly 51 are adjusted so that the temperature rise curve in the first chamber 11 is the same as the temperature rise curve in the second chamber 12;

[0082] In step S3, the square of the current in step S2 is integrated, and according to the principle that the temperature changes of the heat transfer medium in the first chamber 11 and the second chamber 12 are the same in the same time, the formula The resistance R of the conductive layer of current collector 90 is calculated, where R1 is the resistance of conductive element 60, I1 is the current supplied to second electrode assembly 51, measured during testing, I2 is the current supplied to first electrode assembly 31, a constant known quantity, and t is the power supply time for first electrode assembly 31 and second electrode assembly 51, both of which are identical. Finally, the thickness h of the conductive layer of current collector 90 is calculated using the formula R = ρL / S and the formula S = h*d, where ρ is the resistivity of the conductive layer of current collector 90, S is the cross-sectional area of ​​the conductive layer, d is the width of the conductive layer of current collector 90, which can be measured, and L is the length of the conductive layer of current collector 90, which can be measured. Since ρ is known, the thickness h of the conductive layer can be calculated.

[0083] According to the three methods mentioned above, we can know:

[0084] This embodiment, based on the structure of a current collector coating thickness detection device, can provide a current collector coating thickness detection method. During the detection, the current collector sample is placed in a heat-insulating environment, the current collector is energized, and the heat Q generated by the current collector is calculated by measuring the temperature change of the detection environment. The resistance R of the current collector conductive layer is then calculated based on Q, and the thickness h of the current collector conductive layer can be calculated based on R. The current collector coating thickness detection method of the present application is simple to operate, and the detection results can be quickly obtained through computer calculation. In addition, the average thickness of the coating is obtained through the test, avoiding measurement errors caused by uneven thickness.

[0085] 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.

[0086] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0087] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A device for detecting the thickness of a current collector coating, characterized in that: include: A main body (10), wherein a first chamber (11) is provided on the main body (10); a conveying mechanism (20), the conveying mechanism (20) being arranged on the main body (10) and located outside the first chamber (11), the conveying mechanism (20) being used at least to convey a heat-conducting medium to the first chamber (11); a detection mechanism (30), the detection mechanism (30) being arranged in the first chamber (11), the detection mechanism (30) comprising a first electrode assembly (31) and a first temperature detection element (32), the first electrode assembly (31) being used to energize the current collector (90) to be detected, and the first temperature detection element (32) being used to detect the temperature of the heat-conducting medium in the first chamber (11); The main body (10) is further provided with a second chamber (12), the second chamber (12) having the same shape as the first chamber (11), and the conveying mechanism (20) is used to convey the heat-conducting medium to the second chamber (12); The current collector coating thickness detection device further includes: A comparison mechanism (50) is provided in the second chamber (12), and comprises a second electrode assembly (51) and a second temperature detection element (52). The second electrode assembly (51) is used to energize a conductive element (60) of known resistance, and the second temperature detection element (52) is used to detect the temperature of the heat-conducting medium in the second chamber (12).

2. The current collector coating thickness detection device according to claim 1, characterized in that: A first heat insulation layer (40) is provided on the inner wall surface of the first chamber (11).

3. The current collector coating thickness detection device according to claim 1, characterized in that: The inner wall surface of the second chamber (12) is provided with a second heat insulation layer (70).

4. The current collector coating thickness detection device according to claim 1, characterized in that: The first electrode assembly (31) and the second electrode assembly (51) both comprise a positive electrode and a negative electrode, the positive electrode and the negative electrode are spaced apart, and a detachable conductive clip is provided on the positive electrode and the negative electrode.

5. The current collector coating thickness detection device according to claim 1, characterized in that: The conveying mechanism (20) comprises: a liquid storage container (21), the liquid storage container (21) being used to store the heat-conducting medium; an infusion tube, the infusion tube comprising a first infusion tube (22) and a second infusion tube (23), the two ends of the first infusion tube (22) being respectively in communication with the first chamber (11) and the liquid storage container (21), and the two ends of the second infusion tube (23) being respectively in communication with the second chamber (12) and the liquid storage container (21); A liquid return pipe, the liquid return pipe comprising a first liquid return pipe (24) and a second liquid return pipe (25), the two ends of the first liquid return pipe (24) being respectively connected to the bottom of the first chamber (11) and the liquid storage container (21), and the two ends of the second liquid return pipe (25) being respectively connected to the second chamber (12) and the liquid storage container (21).

6. The current collector coating thickness detection device according to claim 5, characterized in that: The current collector coating thickness detection device further includes: A temperature control system (80) is provided on the main body (10) and is used to control the temperature of the heat-conducting medium in the liquid storage container (21).

7. The current collector coating thickness detection device according to claim 1, characterized in that: A stirrer (100) is provided in both the first chamber (11) and the second chamber (12).

8. The current collector coating thickness detection device according to claim 1, characterized in that: Liquid level detection elements are provided in both the first chamber (11) and the second chamber (12).

9. A method for detecting the thickness of a current collector, characterized in that: The current collector coating thickness detection method is performed using the current collector coating thickness detection device according to any one of claims 1 to 8, and the current collector coating thickness detection method includes: Step S1: placing a sample of the current collector (90) to be tested into the first chamber (11), introducing a heat-conducting medium into the first chamber (11) using the conveying mechanism (20), and then passing an electric current through the current collector (90) using the first electrode assembly (31); Step S2: using the first temperature detection element (32) to detect the temperature change of the heat-conducting medium in the first chamber (11); Step S3: Calculate the heat Q generated when the current collector (90) is energized based on the detection result of the first temperature detection element (32), calculate the resistance R of the conductive layer of the current collector (90) based on Q, and calculate the thickness h of the conductive layer of the current collector (90) based on the resistance R.

10. The method for detecting the thickness of the current collector according to claim 9, wherein: In step S2, the temperature of the heat-conducting medium in the first chamber (11) is detected twice using the first temperature detection element (32); In the step S3, the temperature difference ΔT between the two detections of the heat conducting medium is calculated, and the heat Q generated when the collector (90) is energized is calculated using the formula Q=cmΔT, and the heat Q generated when the collector (90) is energized is calculated using the formula Q=I 2 The resistance R of the conductive layer of the current collector (90) is calculated by Rt, wherein c is the specific heat capacity of the heat-conducting medium, m is the mass of the heat-conducting medium in the first chamber (11), I is the current flowing through the first electrode assembly (31), and t is the time during which the first electrode assembly (31) is energized.

11. The method for detecting the thickness of the current collector according to claim 10, wherein: The step S1 further comprises: placing a conductive element (60) of known resistance into a second chamber (12) of the current collector coating thickness detection device, and using the conveying mechanism (20) to pass a heat-conducting medium of the same mass as that of the first chamber (11) into the second chamber (12), and then using the second electrode assembly (51) of the current collector coating thickness detection device to pass a current through the conductive element (60), so that the first electrode assembly (31) and the second electrode assembly (51) are supplied with the same current; In step S2, the temperature of the heat-conducting medium in the first chamber (11) is detected by using the first temperature detection element (32) until the temperature of the heat-conducting medium reaches Tstop, and the power-on time t1 of the first electrode assembly (31) is recorded; the temperature of the heat-conducting medium in the second chamber (12) is detected by using the second temperature detection element (52) of the current collector coating thickness detection device until the temperature of the heat-conducting medium reaches Tstop, and the power-on time t2 of the second electrode assembly (51) is recorded; In step S3, based on the principle that the temperature changes in the first chamber (11) and the second chamber (12) are the same, the resistance R of the conductive layer of the current collector (90) is calculated using the formula R=R1t2 / t1, where R1 is the resistance of the conductive element (60).

12. The method for detecting the thickness of the current collector according to claim 10, wherein: The step S1 further comprises: placing a conductive element (60) of known resistance into the second chamber (12) of the current collector coating thickness detection device, and using the conveying mechanism (20) to pass the heat-conducting medium of the same mass as that of the first chamber (11) into the second chamber (12), and then using the second electrode assembly (51) of the current collector coating thickness detection device to pass current through the conductive element (60); In step S2, the first temperature detection element (32) and the second temperature detection element (52) of the current collector coating thickness detection device are used to monitor the temperatures in the first chamber (11) and the second chamber (12), respectively, and the supply currents of the first electrode assembly (31) and the second electrode assembly (51) are adjusted so that the temperature rise curve in the first chamber (11) is the same as the temperature rise curve in the second chamber (12); In step S3, the square of the current in step S2 is integrated, and based on the principle that the temperature changes of the heat transfer medium in the first chamber (11) and the second chamber (12) are the same in the same time, the formula The resistance R of the conductive layer of the current collector (90) is calculated, wherein R1 is the resistance of the conductive element (60), I1 is the power supply current of the second electrode assembly (51), I2 is the power supply current of the first electrode assembly (31), and t is the power supply time of the first electrode assembly (31) and the second electrode assembly (51).

13. The method for detecting the thickness of the current collector according to any one of claims 9 to 12, characterized in that: In step S3, the thickness h of the conductive layer of the current collector (90) is calculated using the formula R=ρL / S and the formula S=h*d, wherein ρ is the resistivity of the conductive layer of the current collector (90), S is the cross-sectional area of ​​the conductive layer, d is the width of the conductive layer of the current collector (90), and L is the length of the current collector (90).

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