Pole piece coating weight detection method, system, device and storage medium

Abstract

The application belongs to the technical field of battery cell manufacturing, and discloses a pole piece coating weight detection method, system, device and storage medium. The method comprises the following steps: a first detection equipment group is used to detect the area density of a pole piece substrate to determine the substrate area density corresponding to a plurality of radiation types; in the case that a plurality of layers of materials are coated on the first surface of the pole piece substrate, a second detection equipment group is used to detect the area density of the coated pole piece to determine the coated pole piece area density corresponding to the plurality of radiation types; for each radiation type, the substrate weight and the total weight of the coated pole piece under a preset detection area are determined based on the corresponding substrate area density and the coated pole piece area density; and the difference between the total weight corresponding to each radiation type and the substrate weight is determined as the coating weight of the target layer material corresponding to each radiation type. The method can realize synchronous and accurate detection of the coating weight of each single layer material in multi-layer coating.

Description

Technical Field

[0001] This application relates to the field of battery cell manufacturing technology, and in particular to a method, system, device and storage medium for detecting the weight of electrode coating. Background Technology

[0002] In lithium-ion battery manufacturing, the electrode coating process is a crucial step affecting battery performance. With the continuous improvement of battery performance requirements such as energy density and cycle life, multilayer coating technology has gradually been applied. This technology optimizes the electrochemical performance and interfacial stability of the electrode by sequentially coating multiple layers of materials with different functions onto the electrode substrate.

[0003] Currently, weight measurement after multilayer coating typically relies on areal density measurement equipment based on radiation sources. However, existing methods either only measure the total weight after double-layer coating or require a step-by-step operation: first measuring the weight of the lower layer, then the total weight of both layers, and finally calculating the weight of the upper layer by subtraction. These methods cannot simultaneously and in real-time obtain the weight of each of the two individual layers, making it difficult to effectively monitor the weight uniformity of the two layers. This affects quality control during production, and consequently impacts the consistency of battery performance and yield. Summary of the Invention

[0004] The main objective of this application is to provide a method, system, device, and storage medium for detecting the weight of electrode coatings, which can achieve synchronous and accurate detection of the coating weight of each single layer material in multilayer coating.

[0005] In a first aspect, this application provides a method for detecting the weight of electrode coatings, the method comprising the following steps:

[0006] The surface density of the electrode substrate is detected by the first detection equipment group to determine the surface density of the substrate corresponding to multiple ray types.

[0007] When the first surface of the electrode substrate is coated with multiple layers of material, the surface density of the coated electrode is detected by the second detection equipment group to determine the surface density of the coated electrode corresponding to each of the multiple ray types.

[0008] For each type of radiation, the weight of the substrate and the total weight after coating are determined based on the corresponding substrate surface density and the electrode surface density after coating, under the preset detection area.

[0009] The difference between the total weight corresponding to each ray type and the weight of the substrate is determined as the coating weight of the target layer material corresponding to each ray type, wherein the target layer material corresponding to each ray type is the layer material with the highest mass absorption coefficient for the ray type among the multilayer materials.

[0010] In this embodiment, the areal density of the uncoated electrode substrate is measured using a first detection device group to determine the areal density of the substrate corresponding to various ray types. Subsequently, after multilayer coating is completed on the first surface of the electrode substrate, the areal density of the coated electrode is measured using a second detection device group to determine the areal density of the coated electrode corresponding to various ray types. Next, for each ray type, based on the corresponding substrate areal density and the areal density of the coated electrode, the weight of the substrate and the total weight after coating are determined for a preset detection area. Since the same ray is absorbed differently when passing through different materials due to variations in material composition, a specific layer of material will have a significantly stronger absorption capacity for a specific ray than other layers. Based on this characteristic, for each ray type, the layer with the highest mass absorption coefficient for that ray type among the multilayer materials coated on the electrode substrate can be used as the target layer material corresponding to that ray type. The areal density changes measured by various rays primarily reflect the coating status of their corresponding target layer materials. Therefore, after obtaining the substrate weight and total weight, the difference between the total weight and the substrate weight corresponding to each ray type is attributed to the coating weight of the target layer material corresponding to that ray type. This allows for the simultaneous, real-time calculation of the coating weight of each individual layer in a multi-layer coating process, enabling continuous monitoring of the weight uniformity of each individual layer, timely detection and correction of coating abnormalities, significantly improving the weight consistency and production process stability of the electrode coating process, and ultimately enhancing the consistency and yield of battery performance.

[0011] In some embodiments, the step of detecting the areal density of the electrode substrate using a first detection device group to determine the areal density of the substrate corresponding to multiple radiation types includes:

[0012] For any one of the first detection equipment groups, the incident radiation intensity and transmitted radiation intensity of the electrode substrate are collected by the detection equipment.

[0013] Based on the incident and transmitted radiation intensity of the electrode substrate and the sample mass absorption coefficient, the substrate surface density corresponding to the radiation type of the detection device is determined.

[0014] In this embodiment, the incident and transmitted radiation intensity of the electrode substrate are collected by any of the detection devices in the first detection device group. Combined with the sample mass absorption coefficient obtained in advance through standard sample calibration for the radiation type of that detection device, the substrate areal density corresponding to that radiation type can be accurately calculated. This method determines the substrate areal density based on the principle of radiation absorption and uses the actual sample mass absorption coefficient rather than empirical parameters, significantly improving the accuracy and reliability of areal density measurement.

[0015] In some embodiments, before acquiring the incident radiation intensity and transmitted radiation intensity of the electrode substrate through any of the detection devices in the first group of detection devices, the method further includes:

[0016] The detection equipment is used to collect the incident radiation intensity and transmitted radiation intensity of standard samples.

[0017] The mass absorption coefficient of the sample is determined based on the incident radiation intensity, transmitted radiation intensity, and areal density of the standard sample.

[0018] In this embodiment, before testing the electrode substrate, the incident and transmitted radiation intensities of a standard sample are collected using a testing device. The sample's mass absorption coefficient is then determined by combining this data with the known areal density of the standard sample. This allows for the creation of a specific mass absorption coefficient tailored to each radiation type and the testing device. This absorption coefficient, based on the actual testing equipment and standard sample, better reflects the specific testing scenario and avoids errors caused by using generic coefficients. The resulting sample mass absorption coefficient further improves the accuracy of areal density detection when used for subsequent substrate areal density calculations, laying a solid foundation for the precise calculation of the weight of each coating layer.

[0019] In some embodiments, the step of detecting the areal density of the coated electrode sheet using a second detection device group to determine the areal density of the coated electrode sheet corresponding to each of the plurality of ray types includes:

[0020] For any of the detection devices in the second detection device group, the incident radiation intensity and transmitted radiation intensity of the coated electrode are collected by the detection device.

[0021] Based on the incident and transmitted radiation intensity of the coated electrode and the sample mass absorption coefficient, the surface density of the coated electrode corresponding to the radiation type of the detection device is determined.

[0022] In this embodiment, the incident and transmitted radiation intensities of the coated electrode are collected by any of the detection devices in the second detection device group. Combined with the sample mass absorption coefficient obtained in advance through standard sample calibration for the radiation type of that detection device, the areal density of the coated electrode corresponding to that radiation type can be accurately calculated. This method determines the areal density of the coated electrode based on the principle of radiation absorption and uses the actual measured sample mass absorption coefficient instead of empirical parameters, significantly improving the accuracy and reliability of areal density measurement.

[0023] In some embodiments, determining the substrate weight and the total weight after coating for each radiation type, based on the corresponding substrate areal density and the electrode areal density after coating, under a preset detection area includes:

[0024] For any type of radiation, the product of the corresponding substrate surface density and the coated electrode surface density with the preset detection area is used as the substrate weight measurement value and the total weight measurement value after coating.

[0025] Based on the mapping relationship between the measured value and the true value corresponding to the ray type, the measured value of the substrate weight and the measured value of the total weight are corrected to obtain the substrate weight and the total weight after coating corresponding to the ray type.

[0026] In this embodiment, the measured values ​​of substrate weight and total weight are corrected by establishing a mapping relationship between the measured values ​​and the true values. This eliminates potential systematic biases during the measurement process, making the obtained substrate weight and total weight closer to the true values. Since different types of radiation have different detection characteristics, a dedicated mapping relationship is established for each radiation type, allowing for targeted optimization of the measurement results for each radiation type and further improving the accuracy of the weight data. Accurate substrate weight and total weight are crucial for calculating the coating weight of each target layer material. Therefore, this correction process helps improve the accuracy of coating weight detection, providing more reliable data support for precise monitoring of the electrode coating process.

[0027] In some embodiments, before determining the surface density of the electrode substrate corresponding to multiple radiation types by detecting the surface density of the electrode substrate using the first detection device group, the method further includes:

[0028] For any type of radiation, the average areal density of the electrode substrate is obtained by the detection device corresponding to the radiation type in the first detection device group, and then converted into the average weight measurement value.

[0029] Multiple substrate samples were obtained and weighed at the areal density detection location of the electrode substrate to determine the average actual weight.

[0030] Based on the average weight measurement and the average actual weight of the electrode substrate, the mapping relationship between the measured value and the true value of the substrate weight is determined.

[0031] In this embodiment, a substrate sample is obtained from the areal density detection location of the electrode substrate and weighed to obtain the average actual weight. This average weight is then combined with the average weight measurement obtained from the detection equipment to determine the mapping relationship between the measured and true substrate weight. This mapping relationship accurately reflects the measurement deviation of the detection equipment corresponding to this type of radiation when actually detecting the substrate. Using this to correct the substrate weight measurement effectively improves the accuracy of the substrate weight. Accurate substrate weight is the basis for subsequent calculation of coating weight; therefore, this method helps improve the reliability of coating weight detection for each single layer in multilayer coating, better meeting the needs of electrode coating process monitoring.

[0032] In some embodiments, before determining the surface density of the electrode substrate corresponding to multiple radiation types by detecting the surface density of the electrode substrate using the first detection device group, the method further includes:

[0033] For any type of ray, a target layer material corresponding to the type of ray is coated on the electrode substrate with the target coating parameters to obtain the target electrode segment;

[0034] The average surface density of the target pole segment is obtained by the detection device corresponding to the type of radiation in the second detection device group, and then converted into the average weight measurement value.

[0035] Multiple electrode samples were obtained and weighed at the areal density detection location of the target electrode segment to determine the average actual weight.

[0036] Based on the average weight measurement of the target pole segment and the average actual weight, the mapping relationship between the measured value and the true value of the total weight is determined.

[0037] In this embodiment, by simulating the actual coating process, a target electrode segment is formed by coating a target layer material corresponding to the radiation type onto the electrode substrate. The mapping relationship between the measured total weight and the true total weight is determined by combining the average weight measurement of the target electrode segment by the detection equipment and the average actual weight of the electrode sample. This mapping relationship accurately reflects the measurement deviation of the detection equipment corresponding to the radiation type when actually detecting the coated electrode. Using this to correct the measured total weight after coating effectively improves the accuracy of the total weight after coating, thereby ensuring the accuracy of the weight detection of each target layer material and facilitating more effective monitoring of the electrode coating process.

[0038] In some embodiments, determining the mapping relationship between the measured value and the true value of the total weight based on the average weight measurement of the target pole segment and the average actual weight includes:

[0039] The target coating parameters are changed at least once to recoat the electrode substrate to obtain a new target electrode segment, and the average weight measurement value and the average actual weight value are obtained for the new target electrode segment;

[0040] Based on the average weight measurement and the average actual weight corresponding to multiple target coating parameters, the mapping relationship between the measured value and the true value of the total weight is determined.

[0041] In this embodiment, multiple target pole segments are obtained by changing the target coating parameters. The average weight measurement and the average actual weight are then acquired for each target pole segment. This results in multiple sets of average weight measurement and average actual weight corresponding to multiple target coating parameters. This information is used to determine the mapping relationship between the measured total weight and the true total weight, making the mapping relationship more comprehensive and stable, and capable of covering measurement deviations under different coating amounts. In actual testing, regardless of the coating amount of the target layer material, this mapping relationship can effectively correct the measured total weight, avoiding the problem of inaccurate correction when the coating amount changes, as is often the case with mapping relationships established under a single coating parameter. This further improves the accuracy of total weight detection.

[0042] In some embodiments, the step of detecting the areal density of the coated electrode sheet using a second detection device group to determine the areal density of the coated electrode sheet corresponding to each of the plurality of ray types includes:

[0043] The coated electrode is scanned along the same trajectory as the electrode substrate by the second detection equipment group.

[0044] Based on the scanning results, the surface density of the coated electrode is determined one-to-one with the detection location of the substrate surface density corresponding to each type of radiation.

[0045] In this embodiment, the second detection device group scans the coated electrode sheet along the same trajectory as the first detection device group, ensuring a one-to-one correspondence between the detection positions of the substrate areal density and the coated electrode sheet areal density. This precise matching avoids the problem of mismatch between the substrate weight and the total weight caused by different detection positions, allowing the difference between the two to accurately reflect the coating weight of the target layer material at the same location. This improves the accuracy of detecting the coating weight of each target layer material, helps to more accurately monitor the coating uniformity at different locations of the electrode sheet, promptly detects local coating anomalies, and further improves the weight consistency of the electrode sheet coating process.

[0046] In some embodiments, the step of scanning the coated electrode sheet along the same trajectory as the first detection device group on the electrode sheet substrate using the second detection device group includes:

[0047] In response to the first device in the first detection device group starting a scanning operation, the electrode tape length is accumulated. The first device is any device in the first detection device group.

[0048] When the length of the electrode strip is equal to the target distance, the second device is triggered to start the scanning operation. The second device is the device in the second detection device group with the same X-ray type as the first device. The target distance is the distance between the first device and the second device.

[0049] The distances between the scanning start and end points of the second device and the lateral edge of the electrode are controlled to be consistent with the corresponding distances when the first device is scanning.

[0050] In this embodiment, in response to the first device initiating a scanning operation, the electrode tape length is accumulated. When the electrode tape length equals the target distance between the first and second devices, the second device is triggered to initiate scanning. The starting and ending points of the second device's scanning are controlled to be consistent with the corresponding distances during the first device's scanning, ensuring precise overlap of the scanning trajectory in both longitudinal and lateral dimensions. This precise control of the scanning trajectory maximizes the detection of the substrate surface density and the post-coating electrode surface density at the same location, eliminating the problem of mismatched detection positions caused by positional deviations during electrode transport. Consequently, the coating weight calculated based on the substrate surface density and the post-coating electrode surface density accurately reflects the actual coating situation at that location, further improving the accuracy and reliability of coating weight detection and providing strong support for refined monitoring of the electrode coating process.

[0051] In some embodiments, after determining the difference between the total weight corresponding to each ray type and the weight of the substrate as the coating weight of the target layer material corresponding to each ray type, the method further includes:

[0052] Compare the coating weight of each target layer material with the corresponding preset weight range;

[0053] If the coating weight exceeds the preset weight range, adjust the coating parameters of the corresponding material layer.

[0054] In this embodiment, closed-loop control of the electrode coating process is achieved by comparing the coating weight of each target layer material with a preset weight range and adjusting the coating parameters of the corresponding material layer when the weight exceeds the range. This real-time feedback and adjustment mechanism can promptly correct any abnormal coating weight, preventing the abnormality from escalating and resulting in a large number of defective electrodes. Simultaneously, monitoring and adjusting each individual layer material separately enables precise control of each layer in multi-layer coating, ensuring that the coating weight of each layer meets process requirements. This significantly improves the consistency and stability of electrode coating, reduces production costs, and increases the yield and performance consistency of battery products.

[0055] In some embodiments, after determining the difference between the total weight corresponding to each ray type and the weight of the substrate as the coating weight of the target layer material corresponding to each ray type, the method further includes:

[0056] The coated electrode sheet is then flipped over.

[0057] The surface density of the electrode sheet after surface flipping is detected by the third detection equipment group to determine the surface density of the flipped electrode sheet corresponding to multiple ray types. The surface density of the flipped electrode sheet is the composite surface density of the electrode sheet substrate and the coated material.

[0058] When the second surface of the electrode is coated with multiple layers of material, the surface density of the electrode after secondary coating is detected by the fourth detection equipment group to determine the surface density of the electrode after secondary coating corresponding to the multiple ray types.

[0059] Based on the surface density of the flipped electrode and the surface density of the electrode after secondary coating corresponding to each type of ray, the weight of the flipped electrode and the total weight after secondary coating under the preset detection area are determined.

[0060] The difference between the total weight corresponding to each ray type and the weight of the flipped electrode is determined as the coating weight of the target layer material corresponding to each ray type.

[0061] In this embodiment, after completing the multilayer coating of the first surface and determining the coating weight of each target layer material, the coated electrode is further flipped, and the areal density of the flipped electrode is measured by a third detection device group to determine the areal density of the flipped electrode corresponding to each of the multiple ray types. This areal density reflects the comprehensive absorption characteristics of the composite structure formed by the electrode substrate and the coating material on the first surface for ray absorption. Subsequently, multilayer material coating is performed on the second surface of the electrode, and the areal density of the electrode after the second coating is measured by a fourth detection device group to determine the areal density of the electrode after the second coating corresponding to each ray type. Based on the above two sets of areal density data, the weight of the flipped electrode and the total weight after the second coating under a preset detection area can be accurately calculated, and the difference between the two can be attributed to the coating weight of the target layer material with the highest mass absorption coefficient for that ray on the second surface according to the ray type. Therefore, this solution enables independent, real-time, and accurate coating weight detection for each single layer of material on the second surface, thereby achieving full-process monitoring of the double-sided multilayer coating process. This improves the weight symmetry, interlayer consistency, and overall process stability of the double-sided coated electrode, further ensuring the consistency and reliability of the battery in terms of energy density, cycle life, and safety performance.

[0062] Secondly, to achieve the above objectives, this application also proposes a coating system, the system comprising:

[0063] Electrode transport equipment is used to transport electrode substrates along the length of the substrate.

[0064] The first coating device, located on the electrode transfer device, is used to coat a multilayer material onto the first surface of the electrode substrate.

[0065] The first testing equipment group, located upstream of the first coating equipment, is used to test the surface density of the electrode substrate and determine the surface density of the substrate corresponding to multiple ray types.

[0066] The second testing equipment group, located downstream of the first coating equipment, is used to test the surface density of the coated electrode and determine the surface density of the coated electrode corresponding to multiple ray types.

[0067] The processor, which is communicatively connected to the first detection device group and the second detection device group, is used to determine the weight of the substrate and the total weight after coating under a preset detection area based on the substrate surface density and the electrode surface density after coating for each type of radiation; and to determine the difference between the total weight and the substrate weight for each type of radiation as the coating weight of the target layer material for each type of radiation, wherein the target layer material for each type of radiation is the layer material with the highest mass absorption coefficient for the radiation type among the multilayer materials.

[0068] In this embodiment, by integrating an electrode transfer device, a coating device, a first and second detection device group upstream and downstream of the coating device, and a processor into the coating system, the coating system possesses multiple functions such as electrode transfer, coating, detection, and data processing. This enables real-time, synchronous detection of the coating weight of each single layer of material in multi-layer coating. Through this integrated system, the coating weight of each layer can be continuously monitored during production, allowing for timely detection of problems and implementation of corrective measures. This effectively improves the automation level and monitoring efficiency of the electrode coating process, ensuring the stability and consistency of electrode quality, and ultimately enhancing the production quality of the battery.

[0069] In some embodiments, the system further includes:

[0070] The third testing equipment group, located downstream of the second testing equipment group, is used to detect the surface density of the electrode sheet after surface flipping, and to determine the surface density of the flipped electrode sheet corresponding to multiple ray types. The surface density of the flipped electrode sheet is the composite surface density of the electrode sheet substrate and the coated material.

[0071] The second coating device, located downstream of the third testing device group, is used to coat the second surface of the electrode with a multilayer material.

[0072] The fourth testing equipment group, located downstream of the second coating equipment, is used to test the surface density of the electrode sheet after secondary coating and determine the surface density of the electrode sheet after secondary coating corresponding to the multiple ray types.

[0073] The processor is further configured to determine the weight of the flipped electrode and the total weight after secondary coating under a preset detection area based on the surface density of the flipped electrode and the surface density of the electrode after secondary coating corresponding to each ray type; and to determine the difference between the total weight and the weight of the flipped electrode corresponding to each ray type as the coating weight of the target layer material corresponding to each ray type.

[0074] In this embodiment, by further adding a third detection equipment group, a second coating equipment, and a fourth detection equipment group to the original coating system, and combining this with the processor's data analysis of the second surface coating process, the system gains the ability to detect double-sided multilayer coatings on the electrode sheets, forming a complete double-sided quality control system. This significantly improves the weight symmetry, interlayer uniformity, and process consistency of the double-sided coated electrode sheets, greatly enhancing the manufacturing precision and reliability of the battery electrode sheets.

[0075] Thirdly, to achieve the above objectives, this application also proposes an electrode coating weight detection device, the device comprising: a memory, a processor, and an electrode coating weight detection program stored in the memory and running on the processor, the electrode coating weight detection program being configured to implement the steps of the electrode coating weight detection method as described above.

[0076] Fourthly, to achieve the above objectives, this application also proposes a storage medium storing an electrode coating weight detection program, wherein the electrode coating weight detection program, when executed by a processor, implements the steps of the electrode coating weight detection method described above.

[0077] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0078] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0079] Figure 1 A schematic flowchart illustrating a method for detecting the weight of electrode coatings provided in some embodiments of this application;

[0080] Figure 2 A schematic diagram of the overall layout of a coating system provided for some embodiments of this application;

[0081] Figure 3 A schematic diagram of a calibration process provided for some embodiments of this application;

[0082] Figure 4 A schematic diagram illustrating a first detection device group scanning a standard sample, provided for some embodiments of this application;

[0083] Figure 5 A schematic diagram illustrating a first detection device group scanning an electrode substrate according to some embodiments of this application;

[0084] Figure 6 A schematic diagram illustrating a second detection device group scanning a target pole segment, provided for some embodiments of this application;

[0085] Figure 7 A schematic diagram of a coating weight detection process provided for some embodiments of this application;

[0086] Figure 8 A schematic diagram illustrating the coating weight detection of a coating system provided in some embodiments of this application;

[0087] Figure 9 A schematic diagram of scanning trajectory synchronization in a coating system provided for some embodiments of this application;

[0088] Figure 10 A schematic diagram of a coated electrode sheet provided in an embodiment of this application;

[0089] Figure 11 This is a schematic diagram of the overall layout of another coating system provided in an embodiment of this application.

[0090] The reference numerals in the detailed embodiments are as follows:

[0091] 01: First detection equipment group; 02: Second detection equipment group; 03: Radioactive source; 04: Detector; 05: First coating equipment; 06: First drying equipment; 07: Electrode transfer equipment; 08: First standard sample; 09: Second standard sample; 10: Substrate; 11: First layer material; 12: Second layer material; 13: Double layer material; 14: Electrode; 15: Scan start point; 16: Scan end point; D: Distance between scan start point and the lateral edge of the electrode; D1: Distance between scan end point and the lateral edge of the electrode; 17: Flipping mechanism; 18: Third detection equipment group; 19: Fourth detection equipment group; 20: Second coating equipment; 21: Second drying equipment.

[0092] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0093] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0094] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0095] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0096] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0097] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0098] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0099] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0100] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0101] In lithium-ion battery manufacturing, the electrode coating process is one of the key steps affecting battery performance. As market demands for battery energy density, cycle life, safety, and consistency continue to increase, traditional single-layer coating technology is no longer sufficient to meet the performance requirements of high-end battery products. Multilayer coating technology has emerged and is gradually gaining widespread application. This technology optimizes the electrochemical performance and interfacial stability of the electrode by sequentially coating multiple layers of materials with different electrochemical functions on the same surface of the electrode substrate.

[0102] In multilayer coating processes, the uniformity of the coating weight distribution and the stability of the interlayer ratio directly determine the electrode's capacity, internal resistance characteristics, thermal stability, and overall electrochemical performance. These are core process parameters that must be strictly controlled during production. Accurate and real-time measurement of the coating weight of each layer not only helps improve the consistency and reliability of battery performance but also effectively reduces quality fluctuations and scrap rates during production, thereby significantly reducing manufacturing costs.

[0103] The current approach involves first measuring the areal density of the electrode after the first coating layer to obtain the weight of the lower layer material. After the second coating layer is applied, the areal density of the coated electrode is measured again to obtain the total weight of the two coating layers. The weight of the upper layer material is then calculated by the difference. However, this method has significant limitations. It cannot obtain the coating weight of each layer in real time and synchronously, resulting in insufficient monitoring of the weight uniformity of each layer. Especially in high-speed continuous production, quality fluctuations in the coating process are difficult to detect and correct in a timely manner, easily causing batch quality risks and seriously affecting the consistency and yield of batteries.

[0104] In this embodiment, a first detection device group and a second detection device group are provided. Each group includes multiple detection devices with different radiation types, and both groups use the same radiation type. The first detection device group measures the areal density of the uncoated electrode substrate to determine the areal density corresponding to each radiation type. Subsequently, after multilayer coating is applied to the same surface of the electrode substrate, the second detection device group measures the areal density of the coated electrode to determine the areal density corresponding to each radiation type. Then, for each radiation type, based on the corresponding substrate areal density and the coated electrode areal density, the substrate weight and the total weight after coating are determined for a preset detection area. Since the same type of radiation is absorbed differently by different materials due to variations in material composition, a specific layer of material may have a significantly stronger absorption capacity for a particular radiation type than other layers. Based on this characteristic, for each radiation type, the layer with the highest mass absorption coefficient for that radiation type among the multilayer materials coated on the electrode substrate can be used as the target layer material for that radiation type. The areal density changes measured by various rays primarily reflect the coating status of their corresponding target layer materials. Therefore, after obtaining the substrate weight and total weight, the difference between the total weight and the substrate weight corresponding to each ray type is attributed to the coating weight of the target layer material corresponding to that ray type. This allows for the simultaneous, real-time calculation of the coating weight of each individual layer in a multi-layer coating process, enabling continuous monitoring of the weight uniformity of each individual layer, timely detection and correction of coating abnormalities, significantly improving the weight consistency and production process stability of the electrode coating process, and ultimately enhancing the consistency and yield of battery performance.

[0105] The electrode coating weight detection method provided in this application can be applied in various scenarios. For example, in the scenario where a conductive reinforcement layer and a graphite active layer are coated on the electrode substrate of an anode electrode, the method of this application can be used to detect the coating weight of the conductive reinforcement layer and the graphite active layer in real time during the double-layer coating process. This allows for independent monitoring of the areal density uniformity and proportional stability of the two layers, timely detection of abnormalities such as coating deviation or material breakage, and improvement of the consistency of the electrochemical performance of the negative electrode. As another example, in the scenario where a high-nickel ternary material layer and a surface modification layer are coated on the electrode substrate of a cathode electrode, the difference in absorption of nickel and the surface modification layer by different rays can be used to detect the coating weight of the high-nickel ternary material layer and the surface modification layer separately. This enables precise quality control of key functional layers and effectively optimizes the stability of the positive electrode interface and cycle life.

[0106] Please refer to Figure 1 , Figure 1 A flowchart illustrating a method for detecting the weight of electrode coatings, provided for some embodiments of this application, includes the following steps:

[0107] S10, the surface density of the electrode substrate is detected by the first detection equipment group to determine the surface density of the substrate corresponding to multiple ray types.

[0108] S20, when a multilayer material is coated on the first surface of the electrode substrate, the areal density of the coated electrode is detected by the second detection equipment group to determine the areal density of the coated electrode corresponding to each of the multiple ray types.

[0109] S30, for each type of radiation, based on the corresponding substrate surface density and the electrode surface density after coating, determine the substrate weight and the total weight after coating under the preset detection area.

[0110] S40, the difference between the total weight corresponding to each ray type and the weight of the substrate is determined as the coating weight of the target layer material corresponding to each ray type, wherein the target layer material corresponding to each ray type is the layer material with the highest mass absorption coefficient for that ray type in the multilayer material.

[0111] The first testing equipment group is a collection of devices used to test the areal density of the electrode substrate before coating. It includes multiple testing devices with different types of radiation, such as X-ray testing equipment and beta-ray testing equipment.

[0112] The second testing equipment group is a set of devices used to test the areal density of the coated electrode substrate after it has been coated with multiple layers of material. It consists of multiple testing devices with different types of radiation. The types of radiation used in the second testing equipment group are the same as those used in the first testing equipment group. For example, if the first testing equipment group includes X-ray testing equipment and beta-ray testing equipment, the second testing equipment group must also include X-ray testing equipment and beta-ray testing equipment.

[0113] Detection equipment refers to devices that measure surface density based on the absorption characteristics of specific rays. Its detection principle follows the ray absorption formula: by measuring the change in intensity of rays after they pass through the object being tested, the surface density of the object is inferred. The ray absorption formula is:

[0114] Formula (1):

[0115] in, The intensity of X-ray transmission. The incident intensity of the radiation. The mass absorption coefficient, is the areal density.

[0116] Electrode substrate refers to the basic carrier of lithium battery electrodes. It is the original sheet substrate that has not yet been coated with materials and can be metal foil, such as aluminum foil, copper foil, etc.

[0117] Multilayer materials are multiple functional material layers sequentially coated on the same surface of the electrode substrate, such as active material layer, conductive reinforcement layer, surface modification layer, etc. Each material layer undertakes different electrochemical functions, and the coating weight needs to be tested separately to control the quality of the electrode.

[0118] The target layer material corresponds to a specific type of radiation. It refers to the layer in a multilayer material that has the highest mass absorption coefficient for that specific type of radiation, meaning it is the most sensitive layer for that type of radiation. This characteristic means that when radiation penetrates multiple layers, the attenuation of the radiation intensity is primarily determined by the target layer material, while the influence of the other layers is negligible. Therefore, the changes in areal density detected before and after coating for each type of radiation mainly reflect the coating condition of the corresponding target layer material, thus enabling effective detection of the areal density of the target layer material. Different radiation types correspond to different target layer materials. For example, if the first layer in a multilayer material has the highest mass absorption coefficient for X-rays, then the target layer material for X-rays is the first layer material; if the second layer in a multilayer material has the highest mass absorption coefficient for β-rays, then the target layer material for β-rays is the second layer material.

[0119] Substrate areal density refers to the weight of the electrode substrate per unit area, and is the core parameter tested by the first testing equipment group. Post-coating electrode areal density refers to the total weight per unit area of ​​the entire coated electrode, including the substrate and multiple layers of material, after the electrode substrate has been coated with multiple layers of material; this is the core parameter tested by the second testing equipment group.

[0120] The preset detection area refers to a fixed area parameter that is pre-set when calculating weight, used to convert areal density into weight. Since areal density is the weight per unit area, multiplying it by the preset detection area yields the weight for that area. Therefore, it can be ensured that the calculation of the substrate weight and the total weight after coating are based on the same area benchmark.

[0121] The substrate weight refers to the weight of the electrode substrate corresponding to the preset detection area. For example, the product of the substrate areal density and the preset detection area can be used as the substrate weight. Alternatively, the product of the substrate areal density and the preset detection area can be corrected for errors, and the corrected value can be used as the substrate weight.

[0122] The total weight after coating refers to the total weight of the electrode sheet after coating multiple layers of material, corresponding to the preset detection area. For example, the product of the electrode sheet's surface density after coating and the preset detection area can be used as the total weight after coating. Alternatively, the product of the electrode sheet's surface density after coating and the preset detection area can be corrected, and the corrected value can be used as the total weight of the electrode sheet.

[0123] The coating weight of the target layer material refers to the actual coating weight of a specific layer in a multilayer material. Its value is the difference between the total weight of the target layer material corresponding to the type of radiation and the weight of the substrate corresponding to that radiation type. Because the target layer material has the highest mass absorption coefficient for that radiation type, this difference accurately reflects the coating weight of the target layer material, rather than the coating weight of other layers.

[0124] The mass absorption coefficient refers to the ability of a unit mass of a substance to absorb a specific type of radiation. Different materials have significantly different mass absorption coefficients for different types of radiation. For example, metallic materials have a higher mass absorption coefficient for X-rays than organic materials, while organic materials have a higher mass absorption coefficient for beta rays than metallic materials.

[0125] In this embodiment, a first detection device group detects the uncoated electrode substrate to determine the substrate areal density corresponding to various ray types. Subsequently, after multilayer coating is completed on the first surface of the electrode substrate, a second detection device group detects the areal density of the coated electrode to determine the areal density of the coated electrode corresponding to various ray types. Then, for each ray type, based on the corresponding substrate areal density and the coated electrode areal density, the substrate weight and the total weight after coating are determined for a preset detection area. Since the same ray is absorbed differently when passing through different materials due to variations in material composition, a specific layer of material will have a significantly stronger absorption capacity for a specific ray than other layers. Based on this characteristic, for each ray type, the layer with the highest mass absorption coefficient for that ray type among the multilayer materials coated on the electrode substrate can be used as the target layer material corresponding to that ray type. The areal density changes measured by various rays primarily reflect the coating status of their corresponding target layer materials. Therefore, after obtaining the substrate weight and total weight, the difference between the total weight and the substrate weight corresponding to each ray type is attributed to the coating weight of the target layer material corresponding to that ray type. This allows for the simultaneous, real-time calculation of the coating weight of each individual layer in a multi-layer coating process, enabling continuous monitoring of the weight uniformity of each individual layer, timely detection and correction of coating abnormalities, significantly improving the weight consistency and production process stability of the electrode coating process, and ultimately enhancing the consistency and yield of battery performance.

[0126] In some embodiments, the areal density of the electrode substrate is measured using a first group of detection devices to determine the areal density of the substrate corresponding to multiple radiation types. This includes: for any detection device in the first group of detection devices, acquiring the incident radiation intensity and transmitted radiation intensity of the electrode substrate using that device; and determining the areal density of the substrate corresponding to the radiation type of that detection device based on the incident radiation intensity and transmitted radiation intensity of the electrode substrate, and the sample mass absorption coefficient. The sample mass absorption coefficient is the mass absorption coefficient obtained by detecting a standard sample with a known areal density for the radiation type of the detection device.

[0127] Among them, the incident intensity of the radiation refers to the initial intensity of the radiation emitted by the detection equipment before it reaches the electrode substrate, and it is the benchmark parameter for calculating the degree of radiation attenuation. The transmitted intensity of the radiation refers to the residual intensity of the radiation received by the detection equipment after it has penetrated the electrode substrate, that is, the intensity of the radiation after it has been absorbed by the electrode substrate. The difference between the transmitted intensity and the incident intensity reflects the degree of absorption of the radiation by the electrode substrate.

[0128] The sample mass absorption coefficient is a predetermined mass absorption coefficient of a standard sample for a specific type of radiation, determined by testing the sample with a known areal density. It is used to establish the calculation relationship between radiation attenuation and the areal density of an unknown substrate, ensuring the accuracy of areal density testing.

[0129] Standard samples are reference materials with known areal densities, such as precisely measured standard copper foil or aluminum foil. They are used to calibrate testing equipment, determine the sample mass absorption coefficient, and serve as a reference to ensure the reliability of test results. Different types of radiation require different standard samples. For example, for any given radiation type, a material with a composition similar to the target layer material corresponding to that radiation type can be selected as the standard sample. This ensures that the absorption characteristics of the standard sample for that radiation are highly consistent with the absorption behavior of the actual target layer material under the same conditions, thereby improving the accuracy of the sample mass absorption coefficient calibration, reducing measurement deviations caused by differences in material composition, and providing a reliable basis for the subsequent accurate calculation of areal density and coating weight.

[0130] For example, by substituting the incident radiation intensity and transmitted radiation intensity of the electrode substrate, as well as the sample mass absorption coefficient, into the following modified radiation absorption formula, the substrate areal density corresponding to the radiation type of the detection device can be obtained.

[0131] Formula (2):

[0132] in, The intensity of X-ray transmission. The incident intensity of the radiation. The mass absorption coefficient, is the areal density.

[0133] For example, for any one of the detection devices in the first detection device group, the incident radiation intensity and transmitted radiation intensity of the electrode substrate can be collected multiple times by the detection device; the average incident radiation intensity and the average transmitted radiation intensity of the collected data can be obtained; based on the average incident radiation intensity and the average transmitted radiation intensity of the electrode substrate, and the sample mass absorption coefficient, the substrate areal density corresponding to the radiation type of the detection device can be determined. The number of times the incident radiation intensity and transmitted radiation intensity are collected can be adjusted according to actual needs; for example, the number of collections can be set to be greater than 5. This embodiment of the application does not limit the specific values ​​used.

[0134] Understandably, by substituting the average incident and transmitted radiation intensities of the electrode substrate, along with the sample mass absorption coefficient, into the modified radiation absorption formula described above, the substrate areal density corresponding to the radiation type of the testing equipment can be obtained. This effectively reduces random errors caused by radiation source fluctuations, detector noise, environmental interference, or minor local defects in the electrode during a single measurement, improving the stability and reliability of radiation incident and transmitted radiation intensities, thereby enhancing the accuracy of the substrate areal density calculation results.

[0135] In this embodiment, the incident and transmitted radiation intensity of the electrode substrate are collected by any of the detection devices in the first detection device group. Combined with the sample mass absorption coefficient obtained in advance through standard sample calibration for the radiation type of that detection device, the substrate areal density corresponding to that radiation type can be accurately calculated. This method determines the substrate areal density based on the principle of radiation absorption and uses the actual sample mass absorption coefficient rather than empirical parameters, significantly improving the accuracy and reliability of areal density measurement.

[0136] In some embodiments, for any of the detection devices in the first group of detection devices, before acquiring the incident radiation intensity and transmitted radiation intensity of the electrode substrate through the detection device, the method further includes: acquiring the incident radiation intensity and transmitted radiation intensity of a standard sample through the detection device; and determining the sample mass absorption coefficient based on the incident radiation intensity, transmitted radiation intensity, and areal density of the standard sample.

[0137] For example, by substituting the incident and transmitted radiation intensity of the standard sample, as well as its areal density, into the following modified radiation absorption formula, the sample mass absorption coefficient can be obtained.

[0138] Formula (3):

[0139] in, The intensity of X-ray transmission. The incident intensity of the radiation. The mass absorption coefficient, is the areal density.

[0140] For example, for any one of the detection devices in the first detection device group, the incident radiation intensity and transmitted radiation intensity of the standard sample can be collected multiple times using that device; the average incident radiation intensity and the average transmitted radiation intensity of the collected samples are obtained; and the sample mass absorption coefficient of the standard sample is determined based on the average incident radiation intensity, the average transmitted radiation intensity, and the areal density of the standard sample. The number of times the incident radiation intensity and transmitted radiation intensity are collected can be adjusted according to actual needs; for example, the number of collections can be set to be greater than 5. This embodiment of the application does not limit the specific values ​​used.

[0141] It is understandable that by substituting the average incident and transmitted radiation intensity of the standard sample, as well as the areal density, into the modified radiation absorption formula (Formula (3)), the sample mass absorption coefficient can be obtained. This effectively reduces the impact of random noise and transient interference in a single measurement on the absorption coefficient calibration results, improves the calculation accuracy and stability of the sample mass absorption coefficient, and ensures that the coefficient truly reflects the average absorption characteristics of the standard sample under a specific radiation type, thereby providing an accurate and reliable calibration basis for subsequent areal density testing of the substrate and coating layer.

[0142] In this embodiment, before testing the electrode substrate, the incident and transmitted radiation intensities of a standard sample are collected using a testing device. The sample's mass absorption coefficient is then determined by combining this data with the known areal density of the standard sample. This allows for the creation of a specific mass absorption coefficient tailored to each radiation type and the testing device. This absorption coefficient, based on the actual testing equipment and standard sample, better reflects the specific testing scenario and avoids errors caused by using generic coefficients. The resulting sample mass absorption coefficient further improves the accuracy of areal density detection when used for subsequent substrate areal density calculations, laying a solid foundation for the precise calculation of the weight of each coating layer.

[0143] In some embodiments, the areal density of the coated electrode is measured by a second group of detection devices to determine the areal density of the coated electrode corresponding to multiple radiation types. This includes: for any detection device in the second group of detection devices, acquiring the incident radiation intensity and transmitted radiation intensity of the coated electrode using that detection device; and determining the areal density of the coated electrode corresponding to the radiation type of that detection device based on the incident radiation intensity and transmitted radiation intensity of the coated electrode, as well as the sample mass absorption coefficient, wherein the sample mass absorption coefficient is the mass absorption coefficient obtained by detecting a standard sample with a known areal density for the radiation type of that detection device.

[0144] Among them, the coated electrode refers to the electrode on which multiple layers of material have been coated on the surface of the electrode substrate. At this time, its structure is a composite of the substrate and the multi-layer coating material, and it is the object of detection of the second detection equipment group.

[0145] The incident intensity of radiation refers to the initial intensity of the radiation emitted by the testing equipment before it reaches the coated electrode. It is the benchmark parameter for calculating the degree of radiation attenuation. The transmitted intensity of radiation refers to the residual intensity of the radiation received by the testing equipment after it has penetrated the coated electrode. In other words, it is the intensity of the radiation after it has been absorbed by the coated electrode. The difference between the transmitted intensity and the incident intensity reflects the degree of radiation absorption by the coated electrode.

[0146] For example, for any of the detection devices in the second detection device group, the incident intensity and transmission intensity of the radiation on the coated electrode, as well as the sample mass absorption coefficient, are substituted into the deformed radiation absorption formula (2) to obtain the surface density of the coated electrode corresponding to the radiation type of the detection device.

[0147] For example, for any one of the detection devices in the second detection device group, the incident and transmitted radiation intensities of the coated electrode can be collected multiple times using that device. The average incident and transmitted radiation intensities from these multiple collections are then obtained. Based on the average incident and transmitted radiation intensities of the coated electrode, and the sample mass absorption coefficient, the areal density of the coated electrode corresponding to the radiation type of that detection device is determined. The number of times the incident and transmitted radiation intensities are collected can be adjusted according to actual needs; for example, the number of collections can be set to be greater than 5. This embodiment does not limit the specific values ​​used.

[0148] It is understandable that by substituting the average incident and transmitted radiation intensities of the coated electrode, along with the sample mass absorption coefficient, into the modified radiation absorption formula (2) above, the surface density of the coated electrode corresponding to the radiation type of the detection device can be obtained. This can effectively reduce random errors caused by radiation source fluctuations, detector noise, environmental interference, or minor local defects in the electrode during a single measurement, improve the stability and reliability of radiation incident and transmitted radiation intensities, and thus enhance the accuracy of the calculated surface density of the coated electrode.

[0149] In this embodiment, the incident and transmitted radiation intensities of the coated electrode are collected by any of the detection devices in the second detection device group. Combined with the sample mass absorption coefficient obtained in advance through standard sample calibration for the radiation type of that detection device, the areal density of the coated electrode corresponding to that radiation type can be accurately calculated. This method determines the areal density of the coated electrode based on the principle of radiation absorption and uses the actual measured sample mass absorption coefficient instead of empirical parameters, significantly improving the accuracy and reliability of areal density measurement.

[0150] In some embodiments, for each ray type, the substrate weight and the total weight after coating are determined based on the corresponding substrate areal density and the electrode areal density after coating, under a preset detection area. This includes: for any ray type, multiplying the corresponding substrate areal density and the electrode areal density after coating by the preset detection area, respectively, as the substrate weight measurement value and the total weight measurement value after coating corresponding to that ray type; and correcting the substrate weight measurement value and the total weight measurement value based on the mapping relationship between the measurement value and the true value corresponding to that ray type to obtain the substrate weight and the total weight after coating corresponding to that ray type.

[0151] The substrate weight measurement is a value directly calculated by multiplying the substrate areal density corresponding to the X-ray type by the preset detection area. It is an initial calculation based on data collected by the testing equipment and has not undergone error correction, so it may deviate from the actual substrate weight. The total weight measurement is a value directly calculated by multiplying the coated electrode areal density corresponding to the X-ray type by the preset detection area. Similar to the substrate weight measurement, it is an initial calculation of the total weight of the coated electrode and has also not undergone error correction, so it may deviate from the actual total weight.

[0152] The mapping relationship between the measured value and the true value corresponding to each type of radiation includes: a first mapping relationship and a second mapping relationship. The first mapping relationship is the mapping relationship between the measured value and the true value of the substrate weight, and the second mapping relationship is the mapping relationship between the measured value and the true value of the total weight. Accordingly, for any type of radiation, based on the mapping relationship between the measured value and the true value corresponding to that type of radiation, the measured value of the substrate weight and the measured value of the total weight are corrected to obtain the substrate weight and the total weight after coating corresponding to that type of radiation. This includes: obtaining the first mapping relationship and the second mapping relationship corresponding to that type of radiation; correcting the measured value of the substrate weight corresponding to that type of radiation based on the first mapping relationship to obtain the substrate weight corresponding to that type of radiation; and correcting the measured value of the total weight corresponding to that type of radiation based on the second mapping relationship to obtain the total weight corresponding to that type of radiation.

[0153] The true weight of the substrate is the actual weight of the electrode substrate within the preset testing area. It is directly measured using a high-precision weighing device and serves as the benchmark for establishing the first mapping relationship, as well as the target value after correction of the substrate weight measurement. The true total weight is the actual total weight of the coated electrode within the preset testing area. It is also directly measured using a high-precision weighing device and serves as the benchmark for establishing the second mapping relationship, as well as the target value after correction of the total weight measurement.

[0154] The first mapping relationship is specifically used to correct for substrate weight. It clarifies the correspondence between the measured substrate weight and the true substrate weight, allowing for adjustments to the measured substrate weight to achieve a more accurate result. The second mapping relationship is specifically used to correct for total weight. It clarifies the correspondence between the measured total weight and the true total weight, allowing for adjustments to the measured total weight to achieve a more accurate result after coating.

[0155] The first and second mapping relationships are calibration models established during the system calibration phase by comparing actual physical measurements with test data. These models are used to compensate for systematic deviations in the weight detection process. These mapping relationships can be represented as linear functions, polynomial curves, or lookup tables, and are stored in the coating system's processor after calibration. During subsequent normal production, the processor can directly call the stored mapping relationships to quickly correct the real-time weight measurements without repeated calibration, thus balancing detection accuracy and operational efficiency.

[0156] In this embodiment, the measured values ​​of substrate weight and total weight are corrected by establishing a mapping relationship between the measured values ​​and the true values. This eliminates potential systematic biases during the measurement process, making the obtained substrate weight and total weight closer to the true values. Since different types of radiation have different detection characteristics, a dedicated mapping relationship is established for each radiation type, allowing for targeted optimization of the measurement results for each radiation type and further improving the accuracy of the weight data. Accurate substrate weight and total weight are crucial for calculating the coating weight of each target layer material. Therefore, this correction process helps improve the accuracy of coating weight detection, providing more reliable data support for precise monitoring of the electrode coating process.

[0157] In some embodiments, before determining the areal density of the electrode substrate corresponding to multiple ray types by measuring the areal density of the electrode substrate using the first detection device group, the system first needs to calibrate a first mapping relationship, that is, the mapping relationship between the measured value and the true value of the substrate weight. This is achieved as follows: for any ray type, the average areal density measurement of the electrode substrate is obtained through the detection device corresponding to the ray type in the first detection device group, and this average areal density measurement is converted into an average weight measurement; multiple substrate samples are obtained at the areal density detection location of the electrode substrate and weighed to determine the actual average weight; based on the average weight measurement and the actual average weight of the electrode substrate, the mapping relationship between the measured value and the true value of the substrate weight is determined.

[0158] The average areal density measurement is the calculated average value obtained by repeatedly measuring the areal density of the electrode substrate using the corresponding detection equipment for a specific type of radiation. The substrate locations are different during these multiple measurements. The average weight measurement is the weight value obtained by multiplying the average areal density measurement for a specific type of radiation by a preset detection area. It is the average measured weight of the substrate under that type of radiation, not the actual weight.

[0159] The areal density testing location for the electrode substrate refers to the specific location where X-rays actually irradiate and collect data when testing the areal density of the electrode substrate. Selecting this location to obtain the substrate sample ensures that the weight measurement data and the actual weighing data come from the same area, avoiding calibration deviations caused by location differences.

[0160] The substrate sample is a small piece of substrate cut from the areal density detection location of the electrode substrate and used for actual weighing. Its size is consistent with the preset detection area, and it serves as the physical carrier for obtaining the average actual weight.

[0161] The actual average weight is calculated by weighing multiple substrate samples obtained from multiple detection locations using a high-precision weighing device. It serves as the true weight benchmark within a preset detection area, used to calibrate the average weight measurement and establish the first mapping relationship.

[0162] For example, the ratio between the average actual weighing value and the average weight measurement value is determined as the first mapping relationship. That is, the ratio of the average actual weighing value to the average weight measurement value is used as a relationship parameter. After obtaining the substrate weight measurement value, the substrate weight measurement value is multiplied by this relationship parameter to obtain the corrected substrate weight.

[0163] In this embodiment, a substrate sample is obtained from the areal density detection location of the electrode substrate and weighed to obtain the average actual weight. This average weight is then combined with the average weight measurement obtained from the detection equipment to determine the mapping relationship between the measured and true substrate weight. This mapping relationship accurately reflects the measurement deviation of the detection equipment corresponding to this type of radiation when actually detecting the substrate. Using this to correct the substrate weight measurement effectively improves the accuracy of the substrate weight. Accurate substrate weight is the basis for subsequent calculation of coating weight; therefore, this method helps improve the reliability of coating weight detection for each single layer in multilayer coating, better meeting the needs of electrode coating process monitoring.

[0164] In some embodiments, before obtaining the areal density of the electrode substrate corresponding to multiple ray types by detecting the areal density of the electrode substrate using the first detection device group, the system first needs to calibrate a second mapping relationship, namely the mapping relationship between the measured value and the true value of the total weight. This is implemented as follows: For any ray type, a target layer material corresponding to that ray type is coated on the electrode substrate using the target coating parameters to obtain a target electrode segment; the areal density measurement average of the target electrode segment is obtained through the detection device corresponding to that ray type in the second detection device group, and this is converted into a weight measurement average; multiple electrode samples are obtained at the areal density detection location of the target electrode segment and weighed to determine the actual average weight; based on the weight measurement average of the target electrode segment and the actual average weight, the mapping relationship between the measured value and the true value of the total weight is determined.

[0165] Target coating parameters are standard process parameters set when coating a target layer material corresponding to a specific type of radiation onto an electrode substrate, including, for example, coating speed. A target electrode segment is a small segment of electrode formed by coating a section of target layer material corresponding to a specific type of radiation onto the electrode substrate using the target coating parameters.

[0166] The average areal density measurement of the target electrode segment is calculated by repeatedly measuring the areal density of the target electrode segment using the corresponding detection equipment in the second detection equipment group for a specific type of radiation. The target electrode segment is located at different positions in each of the multiple measurements. This areal density represents the electrode sheet areal density after coating of the substrate and target layer materials. The average weight measurement of the target electrode segment is obtained by multiplying the average areal density measurement of the target electrode segment by the preset detection area. It represents the total measured weight of the substrate and target layer material, not the actual weight.

[0167] The electrode sample is a small piece taken from the areal density detection location of the target electrode segment for actual weighing. Its area is consistent with the preset detection area and includes both the substrate and the target layer material. The average actual weight of the target electrode segment is the average weight calculated by weighing multiple electrode samples taken from multiple detection locations of the target electrode segment using a high-precision weighing device. This value is the true total weight of the substrate and target layer material within the preset detection area.

[0168] For example, the ratio between the average actual weighing value and the average weight measurement value is determined as the second mapping relationship. That is, the ratio of the average actual weighing value to the average weight measurement value is used as a relationship parameter. After obtaining the total weight measurement value, the total weight measurement value is multiplied by this relationship parameter to obtain the corrected total weight.

[0169] In this embodiment, by simulating the actual coating process, a target electrode segment is formed by coating a target layer material corresponding to the radiation type onto the electrode substrate. The mapping relationship between the measured total weight and the true total weight is determined by combining the average weight measurement of the target electrode segment by the detection equipment and the average actual weight of the electrode sample. This mapping relationship accurately reflects the measurement deviation of the detection equipment corresponding to the radiation type when actually detecting the coated electrode. Using this to correct the measured total weight after coating effectively improves the accuracy of the total weight after coating, thereby ensuring the accuracy of the weight detection of each target layer material and facilitating more effective monitoring of the electrode coating process.

[0170] Understandably, the target layer material corresponding to each ray type refers to the layer with the highest mass absorption coefficient for that ray type among multiple layers. During the system calibration phase, this target layer material is selected and coated onto the substrate according to actual process parameters to prepare the target electrode fragment. Based on this, a second mapping relationship is established between the measured and true values ​​of the total weight for that ray type. In other words, the mapping relationship corresponding to each ray type is obtained based on the calibration of its most sensitive layer, i.e., the layer with the highest mass absorption coefficient. Thus, when subsequently testing actual electrodes, even if multiple coatings exist simultaneously, the system can not only more accurately determine which layer's contribution the ray signal primarily reflects, but also correct the measured total weight using the calibrated second mapping relationship, thereby ensuring higher accuracy in the final calculated target layer material coating weight.

[0171] In some embodiments, determining the mapping relationship between the measured value and the true value of the total weight based on the average weight measurement of the target electrode segment and the average actual weight measurement includes: recoating the electrode substrate by changing the target coating parameters at least once to obtain a new target electrode segment, and obtaining the average weight measurement and the average actual weight measurement for the new target electrode segment; and determining the mapping relationship between the measured value and the true value of the total weight based on multiple sets of average weight measurement and average actual weight measurement corresponding to multiple target coating parameters.

[0172] Changing the target coating parameters at least once refers to adjusting the coating parameters at least once after the initial coating to obtain the target electrode fragment, such as changing the coating speed at least once. The purpose is to simulate different coating states that the target layer material may exhibit in actual production, avoiding the limitations of data based on a single parameter. Recoating refers to the operation of recoating the corresponding target layer material onto the uncoated area of ​​the electrode substrate according to the changed target coating parameters, generating a new target electrode fragment.

[0173] Multiple target coating parameters include the initial target coating parameter and a set of all coating parameters obtained after subsequent changes. These parameters cover the commonly used parameter range of target layer materials in actual production, ensuring that the mapping relationship has a sufficiently wide applicability. Multiple sets of weight measurement averages and actual weighing averages are paired data consisting of the weight measurement average and actual weighing average obtained for the target pole segment corresponding to each target coating parameter.

[0174] For example, a second mapping relationship is obtained by linearly fitting multiple sets of weight measurement mean values ​​and actual weighing mean values. The second mapping relationship can be expressed by the following formula:

[0175] Formula (4):

[0176] in, This is the average of the actual weighings. This is the average weight measurement. The slope The intercept is given. The goodness of fit of this second mapping relationship is greater than 0.996, indicating excellent fitting performance and engineering usability.

[0177] It is understandable that in actual production, for any type of radiation, the total weight measured by the detection can be substituted into the formula (4) to obtain the corrected total weight.

[0178] In this embodiment, multiple target pole segments are obtained by changing the target coating parameters. The average weight measurement and the average actual weight are then acquired for each target pole segment. This results in multiple sets of average weight measurement and average actual weight corresponding to multiple target coating parameters. This information is used to determine the mapping relationship between the measured total weight and the true total weight, making the mapping relationship more comprehensive and stable, and capable of covering measurement deviations under different coating amounts. In actual testing, regardless of the coating amount of the target layer material, this mapping relationship can effectively correct the measured total weight, avoiding the problem of inaccurate correction when the coating amount changes, as is often the case with mapping relationships established under a single coating parameter. This further improves the accuracy of total weight detection.

[0179] In some embodiments, the areal density of the coated electrode is detected by the second detection device group to determine the areal density of the coated electrode corresponding to multiple ray types, including: scanning the coated electrode along the same trajectory as the scanning trajectory of the electrode substrate by the first detection device group using the second detection device group; and determining the areal density of the coated electrode corresponding to the detection position of the substrate areal density corresponding to each ray type based on the scanning results.

[0180] The scanning trajectory is the path along which the X-ray irradiation point moves on the electrode surface when the testing equipment performs areal density testing on the electrode substrate or coated electrode. Same-trajectory scanning means that when the second testing equipment group tests the coated electrode, it strictly follows the scanning trajectory used by the first testing equipment group when testing the substrate, ensuring that the movement path of the X-ray irradiation point on the coated electrode completely overlaps with the path used during substrate testing. The purpose is to ensure a one-to-one correspondence between the testing positions on the substrate and the coated electrode, avoiding mismatches in areal density data due to positional deviations.

[0181] The scanning results are the areal density data of each detection position on the coated electrode after the detection equipment completes the same trajectory scan. These data can be matched with the scanning results of the electrode substrate according to their positions.

[0182] The coating electrode surface density, which corresponds one-to-one with the detection position of the substrate surface density, means that the spatial position of each data point in the coating electrode surface density data is precisely aligned with the corresponding position during the substrate surface density detection, ensuring that the two measurements have perfectly matched sampling points in the same physical area.

[0183] In this embodiment, the second detection device group scans the coated electrode sheet along the same trajectory as the first detection device group, ensuring a one-to-one correspondence between the detection positions of the substrate areal density and the coated electrode sheet areal density. This precise matching avoids the problem of mismatch between the substrate weight and the total weight caused by different detection positions, allowing the difference between the two to accurately reflect the coating weight of the target layer material at the same location. This improves the accuracy of detecting the coating weight of each target layer material, helps to more accurately monitor the coating uniformity at different locations of the electrode sheet, promptly detects local coating anomalies, and further improves the weight consistency of the electrode sheet coating process.

[0184] In some embodiments, the coated electrode is scanned along the same trajectory as the electrode substrate by the second detection device group, according to the scanning trajectory of the electrode substrate by the first detection device group. This includes: in response to the first device in the first detection device group starting a scanning operation, accumulating the electrode tape length, wherein the first device is any device in the first detection device group; when the electrode tape length is equal to the target distance, triggering the second device to start a scanning operation, wherein the second device is a device in the second detection device group with the same X-ray type as the first device, and the target distance is the distance between the first device and the second device; and controlling the distance between the scanning start point and end point of the second device and the lateral edge of the electrode to be consistent with the corresponding distance when the first device scans.

[0185] The first device is any one of the testing devices in the first testing device group. Its scanning start time and lateral scanning range will serve as the reference standard for the second device's scanning. The second device is a testing device in the second testing device group that has the exact same X-ray type as the first device. It needs to adjust its own scanning timing and range according to the electrode tape length and the scanning range of the first device to ensure alignment with the scanning trajectory of the first device.

[0186] The electrode travel length is the distance the electrode moves along the production line via the conveyor mechanism. It is accumulated from the start of scanning by the first device and used to determine when the second device should begin scanning, compensating for the physical distance difference between the two devices. The electrode travel length can be determined based on the output of the coating main roller encoder.

[0187] The target distance is the physical distance between the first and second devices in the electrode travel direction. Since the two devices are installed at the front and rear of the coating equipment respectively, the second device is started to scan only after the electrode travel length has accumulated to this distance, ensuring that the same position on the electrode is scanned.

[0188] The lateral edges of the electrode are the two sides along the width of the electrode. They serve as reference boundaries defining the start and end points of the scan, ensuring that the scan range covers the effective area of ​​the electrode. The lateral edges of the electrode can be determined using edge-measuring sensors on the detection device.

[0189] The scanning start and end points are the positions where the X-ray begins and stops irradiating the electrode when the detection device scans laterally along the electrode sheet. By controlling the distance between these two positions and the lateral edge of the electrode sheet, it is ensured that the lateral scanning range of the second device is completely consistent with that of the first device, avoiding lateral offset that could lead to trajectory misalignment.

[0190] In this embodiment, in response to the first device initiating a scanning operation, the electrode tape length is accumulated. When the electrode tape length equals the target distance between the first and second devices, the second device is triggered to initiate scanning. The starting and ending points of the second device's scanning are controlled to be consistent with the corresponding distances during the first device's scanning, ensuring precise overlap of the scanning trajectory in both longitudinal and lateral dimensions. This precise control of the scanning trajectory maximizes the detection of the substrate surface density and the post-coating electrode surface density at the same location, eliminating the problem of mismatched detection positions caused by positional deviations during electrode transport. Consequently, the coating weight calculated based on the substrate surface density and the post-coating electrode surface density accurately reflects the actual coating situation at that location, further improving the accuracy and reliability of coating weight detection and providing strong support for refined monitoring of the electrode coating process.

[0191] In some embodiments, the difference between the total weight corresponding to each ray type and the weight of the substrate is determined as the coating weight of the target layer material corresponding to each ray type. Then, the coating weight of each target layer material is compared with the corresponding preset weight range. If the coating weight exceeds the preset weight range, the coating parameters of the corresponding material layer are adjusted.

[0192] The preset weight range is a pre-defined acceptable range for coating weight that meets product quality requirements for each target layer material. Coating weight exceeding the preset weight range means that the actual coating weight of a target layer material is higher than the upper limit of the preset weight range or lower than the lower limit. This indicates that the coating amount of that layer material does not meet production standards.

[0193] Coating parameters are production process parameters directly related to the target layer material whose coating weight exceeds the acceptable range, such as coating speed. Coating parameters directly determine the final coating amount of the material. When the coating weight of a target layer material is unacceptable, the corresponding coating parameters are adjusted, including: appropriately reducing the coating speed when the coating weight is above the upper limit; and appropriately increasing the coating speed when the coating weight is below the lower limit, ultimately bringing the coating weight back to the preset acceptable range.

[0194] For example, if the coating weight exceeds the preset weight range, an early warning can be issued to alert operators or the automatic control system that there is an abnormality in the coating of a certain layer of material. This warning can be implemented through audible and visual alarms, pop-up prompts on the human-machine interface, etc., to facilitate timely adjustment of coating parameters, prevent batch quality defects, and ensure the stability of the electrode coating process and product consistency.

[0195] In this embodiment, closed-loop control of the electrode coating process is achieved by comparing the coating weight of each target layer material with a preset weight range and adjusting the coating parameters of the corresponding material layer when the weight exceeds the range. This real-time feedback and adjustment mechanism can promptly correct any abnormal coating weight, preventing the abnormality from escalating and resulting in a large number of defective electrodes. Simultaneously, monitoring and adjusting each individual layer material separately enables precise control of each layer in multi-layer coating, ensuring that the coating weight of each layer meets process requirements. This significantly improves the consistency and stability of electrode coating, reduces production costs, and increases the yield and performance consistency of battery products.

[0196] The above embodiments describe a method for detecting the coating weight of a multilayer material coated on the first surface of an electrode substrate. In other embodiments, the coating weight of a multilayer material coated on the second surface of the electrode substrate can also be detected. This is achieved by: flipping the coated electrode surface; using a third detection device group to detect the surface density of the flipped electrode, determining the surface density of the flipped electrode corresponding to multiple ray types, where the surface density of the flipped electrode is the composite surface density of the electrode substrate and the coated material; when the second surface of the electrode is coated with a multilayer material, using a fourth detection device group to detect the surface density of the electrode after secondary coating, determining the surface density of the electrode after secondary coating corresponding to multiple ray types; based on the surface density of the flipped electrode and the surface density of the electrode after secondary coating corresponding to each ray type, determining the weight of the flipped electrode and the total weight after secondary coating within a preset detection area; and determining the difference between the total weight corresponding to each ray type and the weight of the flipped electrode as the coating weight of the target layer material corresponding to each ray type.

[0197] Here, the first surface and the second surface refer to the two surfaces of the electrode substrate, that is, the second surface is the opposite side of the first surface. After the coating and inspection of the first surface are completed, the second surface is flipped so that it faces upwards for secondary coating. For example, a flipping mechanism, such as a guide roller, can be used to make the originally downward-facing second surface face upwards.

[0198] The third testing equipment group is a set of devices used to test the areal density of the electrode sheet after it has been coated with the first surface material and flipped. It consists of multiple testing devices with different types of radiation, such as X-ray testing equipment and beta-ray testing equipment. The function of these testing devices is to determine the composite areal density of the electrode substrate and the first surface coated material by measuring the attenuation of different rays after penetrating the material, thus providing a benchmark value for the subsequent coating weight test of the second surface.

[0199] The fourth testing equipment group is a set of devices used to test the areal density of the double-coated electrode after multi-layer material coating has been applied to the second surface of the electrode. Similarly, it also consists of multiple testing devices with different radiation types, such as X-ray testing equipment and beta-ray testing equipment. The radiation types used in the fourth testing equipment group must be consistent with those in the third testing equipment group to ensure the validity and accuracy of data comparison. For example, if the third testing equipment group includes X-ray testing equipment and beta-ray testing equipment, the fourth testing equipment group must also include X-ray testing equipment and beta-ray testing equipment.

[0200] The electrode surface density after flipping is the surface density of the electrode after the first surface coating is completed and the electrode is flipped. It is the composite surface density of the substrate and all material layers of the first surface, and serves as a reference value before the second surface coating.

[0201] The electrode surface density after secondary coating is the total surface density of the electrode after multiple layers of material are coated on the second surface, including the surface density of the substrate, the first surface coating, and the second surface coating. It is used to compare with the electrode surface density after flipping to calculate the weight of the newly added coating on the second surface.

[0202] The target layer material corresponding to each type of ray is the layer with the highest mass absorption coefficient for that type of ray among the multilayer materials coated on the second surface.

[0203] It is understandable that the method for detecting the coating weight of each layer of material coated on the second surface is the same as that for detecting the coating weight of each layer of material coated on the first surface, i.e., it is also based on core steps such as multi-ray type areal density detection, same trajectory scanning matching, and weight difference calculation. Specifically, the system obtains the composite areal density of the flipped electrode sheet, equivalent to the new substrate, as a benchmark through the third detection equipment group, and then obtains the areal density of the electrode sheet after secondary coating through the fourth detection equipment group. The data acquisition method and subsequent data processing logic are consistent with the process executed in the detection of the first surface. Therefore, it will not be described in detail again, and the relevant implementation can be directly referred to the aforementioned detection method for the first surface.

[0204] In this embodiment, after completing the multilayer coating of the first surface and determining the coating weight of each target layer material, the coated electrode is further flipped, and the areal density of the flipped electrode is measured by a third detection device group to determine the areal density of the flipped electrode corresponding to each of the multiple ray types. This areal density reflects the comprehensive absorption characteristics of the composite structure formed by the electrode substrate and the coating material on the first surface for ray absorption. Subsequently, multilayer material coating is performed on the second surface of the electrode, and the areal density of the electrode after the second coating is measured by a fourth detection device group to determine the areal density of the electrode after the second coating corresponding to each ray type. Based on the above two sets of areal density data, the weight of the flipped electrode and the total weight after the second coating under a preset detection area can be accurately calculated, and the difference between the two can be attributed to the coating weight of the target layer material with the highest mass absorption coefficient for that ray on the second surface according to the ray type. Therefore, this solution enables independent, real-time, and accurate coating weight detection for each single layer of material on the second surface, thereby achieving full-process monitoring of the double-sided multilayer coating process. This improves the weight symmetry, interlayer consistency, and overall process stability of the double-sided coated electrode, further ensuring the consistency and reliability of the battery in terms of energy density, cycle life, and safety performance.

[0205] To achieve the above objectives, this application also proposes a coating system, which includes:

[0206] Electrode transport equipment is used to transport electrode substrates along the length of the substrate.

[0207] The first coating equipment, located on the electrode transfer equipment, is used to coat a multilayer material on the first surface of the electrode substrate.

[0208] The first testing equipment group, located upstream of the first coating equipment, is used to test the surface density of the electrode substrate and determine the surface density of the substrate corresponding to multiple ray types.

[0209] The second testing equipment group, located downstream of the first coating equipment, is used to test the surface density of the coated electrode and determine the surface density of the coated electrode corresponding to multiple ray types.

[0210] The processor, which is communicatively connected to the first and second detection equipment groups, is used to determine the weight of the substrate and the total weight after coating under a preset detection area based on the substrate surface density and the electrode surface density corresponding to each ray type; and to determine the coating weight of the target layer material corresponding to each ray type as the difference between the total weight corresponding to each ray type and the substrate weight. The target layer material corresponding to each ray type is the layer with the highest mass absorption coefficient for the ray type in the multilayer material.

[0211] The coating system is a complete set of equipment that realizes electrode substrate transfer, multi-layer material coating, areal density detection, and coating weight calculation. It integrates four major functional modules: transfer, coating, detection, and data processing, and can realize full-process automation from substrate input to qualified coated electrode output.

[0212] Electrode transport equipment is a mechanical device used in the system to transport electrode substrates. It can consist of a conveyor belt, drive rollers, tension control system, etc. Its core function is to carry the electrode substrates to be coated and transport them along the length of the substrate at a stable speed, providing a continuous and stable material transport foundation for subsequent coating and testing steps.

[0213] The electrode substrate is the raw electrode substrate that has not yet been coated with any material. It is the initial transport object of the electrode transport equipment and also the coating substrate of the coating equipment.

[0214] The first coating equipment is the core device installed on the electrode transfer equipment for completing material coating. It is equipped with multiple coating units, such as multiple coating dies, corresponding to multiple layers of material. Multiple layers of different materials can be sequentially coated on the same surface of the electrode substrate according to preset process parameters. For example, the first coating equipment is equipped with an intelligent adjustment controller. If the coating weight of any material layer does not meet the preset weight range, the intelligent adjustment controller adjusts the coating amount of that material layer, achieving closed-loop control of the coating weight of a single layer in multi-layer coating.

[0215] Upstream of the first coating equipment is the area in front of the coating equipment in the electrode conveying direction. The first testing equipment group is installed here to perform substrate areal density testing before the electrode substrate enters the coating equipment. Downstream of the first coating equipment is the area behind the coating equipment in the electrode conveying direction. The second testing equipment group is installed here to test the electrode areal density after multi-layer material coating is completed on the electrode substrate.

[0216] The first detection equipment group includes multiple detection devices with different radiation types, while the second detection equipment group uses the same radiation type as the first. Each detection device consists of a radiation source and a detector. The radiation source emits a specific type of radiation, and the detector receives the radiation after it has penetrated the electrode. The intensity of the radiation emitted by the radiation source (the incident radiation intensity) and the intensity of the radiation received by the detector (the transmitted radiation intensity) are used to calculate the areal density for the corresponding radiation type.

[0217] The processor is the data processing core of the coating system, such as an industrial controller or computer. Connected to the first and second detection equipment groups via communication lines, it can receive areal density data transmitted from both groups and calculate the substrate weight, total weight after coating, and target layer material coating weight according to the aforementioned method.

[0218] For example, the processor is also configured to compare the coating weight of each target layer material with the corresponding preset weight range; if the coating weight exceeds the preset weight range, the processor sends the coating weight data of the corresponding material layer to the intelligent adjustment controller of the coating equipment so that the intelligent adjustment controller adjusts the coating parameters of the corresponding material layer.

[0219] For example, the coating system further includes a first drying device located between the first coating device and the second testing device group. This first drying device is used to dry the coated electrode sheet, ensuring the coating is cured and the structure is stabilized, thereby avoiding distortion in the areal density measurement. For example, the first drying device can be an oven, a hot air drying device, an infrared heating device, etc.

[0220] In this embodiment, by integrating an electrode transfer device, a coating device, a first and second detection device group upstream and downstream of the coating device, and a processor into the coating system, the coating system possesses multiple functions such as electrode transfer, coating, detection, and data processing. This enables real-time, synchronous detection of the coating weight of each single layer of material in multi-layer coating. Through this integrated system, the coating weight of each layer can be continuously monitored during production, allowing for timely detection of problems and implementation of corrective measures. This effectively improves the automation level and monitoring efficiency of the electrode coating process, ensuring the stability and consistency of electrode quality, and ultimately enhancing the production quality of the battery.

[0221] In some embodiments, the coating system further includes:

[0222] The third testing equipment group, located downstream of the second testing equipment group, is used to detect the surface density of the electrode sheet after surface flipping, and to determine the surface density of the flipped electrode sheet corresponding to multiple ray types. The surface density of the flipped electrode sheet is the composite surface density of the electrode sheet substrate and the coated material.

[0223] The second coating equipment, located downstream of the third testing equipment group, is used to coat the second surface of the electrode with a multilayer material.

[0224] The fourth testing equipment group, located downstream of the second coating equipment, is used to test the surface density of the electrode sheet after secondary coating and determine the surface density of the electrode sheet after secondary coating corresponding to multiple ray types.

[0225] The processor is also used to determine the weight of the flipped electrode and the total weight after secondary coating under a preset detection area based on the electrode surface density after flipping and the electrode surface density after secondary coating corresponding to each ray type; and to determine the difference between the total weight corresponding to each ray type and the weight of the flipped electrode as the coating weight of the target layer material corresponding to each ray type.

[0226] The third detection equipment group consists of multiple detection devices with different radiation types, each including a corresponding radiation source and detector. The second coating device, located downstream of the third detection equipment group, is used to sequentially coat multiple layers of material onto the flipped second surface of the electrode. Its structure and function are similar to the first coating device, and it can also be equipped with multiple coating dies and an intelligent adjustment controller to achieve independent coating and closed-loop control of each layer of material on the second surface. The fourth detection equipment group, located after the second coating device, is used to detect the overall electrode surface density after double-sided coating. Its radiation type strictly corresponds to that of the third detection equipment group, ensuring data comparability and supporting the processor in accurately calculating the coating weight of each target layer of material on the second surface.

[0227] For example, the coating system also includes a flipping mechanism located on the electrode transfer device and between the second and third inspection device groups. This mechanism flips the electrode with the first surface already coated, so that the originally downward-facing second surface faces upward, facilitating subsequent coating and inspection on the second surface. The flipping mechanism may include guide rollers, a flipping roller group, a robotic arm-type flipping assembly, etc.

[0228] For example, the coating system further includes a second drying device located between the second coating device and the fourth testing device group. This second drying device is used to dry the coated electrode sheet, ensuring the coating is cured and the structure is stabilized, thereby avoiding distortion in the areal density measurement. For example, the second drying device can be an oven, a hot air drying device, an infrared heating device, etc.

[0229] The newly added modules are structurally connected in series with the existing system along the electrode transport path, forming a complete closed-loop process including substrate inspection, first surface coating, post-coating inspection, flipping, second surface reference inspection, second surface coating, second post-coating inspection, and double-sided weight analysis. The entire system is coordinated and controlled by a unified processor, enabling full-process online monitoring and dynamic adjustment of the double-sided and multi-layer material coating process of the electrodes.

[0230] In this embodiment, by further adding a third detection equipment group, a second coating equipment, and a fourth detection equipment group to the original coating system, and combining this with the processor's data analysis of the second surface coating process, the system gains the ability to detect double-sided multilayer coatings on the electrode sheets, forming a complete double-sided quality control system. This significantly improves the weight symmetry, interlayer uniformity, and process consistency of the double-sided coated electrode sheets, greatly enhancing the manufacturing precision and reliability of the battery electrode sheets.

[0231] Figure 2 This is a schematic diagram of the overall layout of a coating system provided in an embodiment of this application. (Reference) Figure 2 The system, along the electrode transport direction, sequentially includes: a first inspection equipment group 01 located upstream, a first coating equipment 05, a first drying equipment 06, and a second inspection equipment group 02 located downstream. The first inspection equipment group 01 includes X-ray and beta-ray inspection equipment, each equipped with a radiation source 03 and a detector 04, used to detect the areal density of the electrode substrate before coating. The first coating equipment 05, located after the first inspection equipment group 01, is used to coat multiple layers of material on the same surface of the electrode substrate. Subsequently, the coated electrode enters the first drying equipment 06 for drying. The second inspection equipment group 02 also includes X-ray and beta-ray inspection equipment, used to detect the areal density of the coated electrode. The entire system is connected in series through the electrode transport equipment 07, realizing a continuous operation process from substrate inspection, coating, drying to post-coating inspection.

[0232] Figure 3 This is a schematic diagram of a calibration process provided in an embodiment of this application. (Reference) Figure 3First, the X-ray detection equipment in the first detection equipment group scans the first standard sample to determine its sample mass absorption coefficient. Then, the β-ray detection equipment in the first detection equipment group scans the second standard sample to determine its sample mass absorption coefficient. Next, the X-ray detection equipment in the first detection equipment group measures the areal density of the electrode substrate and converts it to a weight value. Based on the actual weighing results, a first mapping relationship corresponding to X-rays is established. Then, the β-ray detection equipment in the first detection equipment group measures the areal density of the electrode substrate and converts it to a weight value. Based on the actual weighing results, a first mapping relationship corresponding to β-rays is established. Next, the X-ray detection equipment in the second detection equipment group detects the target electrode segment coated only with the first layer of material, obtaining the measured weight and actual weighing data to establish a second mapping relationship corresponding to X-rays. Here, the first layer of material is the lower layer material corresponding to X-rays. Finally, the β-ray detection equipment in the second detection equipment group detects the target electrode segment coated only with the second layer of material, obtaining the measured weight and actual weighing data to establish a second mapping relationship corresponding to β-rays. Here, the second layer of material is the upper layer material corresponding to β-rays. This process sequentially establishes the mapping relationship between the sample mass absorption coefficient and weight for each type of radiation, providing an accurate calibration basis for subsequent online detection and weight calculation.

[0233] Figure 4 This is a schematic diagram of the first detection device group 01 provided in this embodiment scanning a standard sample. (Reference) Figure 4 The first standard sample 08 is placed between the radiation source 03 and the detector 04 of the X-ray detection equipment to scan it. The second standard sample 09 is placed between the radiation source 03 and the detector 04 of the beta-ray detection equipment to scan it.

[0234] Figure 5 This is a schematic diagram of the first detection device group 01 provided in this application scanning the electrode substrate 10. (See reference) Figure 5 The electrode substrate 10 is placed between the radiation source 03 and the detector 04 of the X-ray detection equipment and the beta-ray detection equipment, respectively, so that the X-ray detection equipment and the beta-ray detection equipment can perform areal density detection on the electrode substrate 10.

[0235] Figure 6 This is a schematic diagram of the second detection device group 02 provided in this application scanning the target pole segment. (Reference) Figure 6 A target pole fragment obtained by coating only the first layer of material 11 on the substrate 10 is placed between the radiation source and the detector of an X-ray detection device to detect the areal density of the target pole fragment. A target pole fragment obtained by coating only the second layer of material 12 on the substrate 10 is placed between the radiation source and the detector of a beta-ray detection device to detect the areal density of the target pole fragment.

[0236] Figure 7 This is a schematic diagram of a coating weight detection process provided in an embodiment of this application. (Reference) Figure 7 After the electrode substrate enters the system, the X-ray and beta-ray detectors in the first detection equipment group measure the substrate's areal density, obtaining the areal density corresponding to each ray type, and send it to the host computer. The host computer converts the areal density of the substrate corresponding to each ray type into the substrate weight corresponding to each ray type and displays it. The X-ray and beta-ray detectors in the second detection equipment group scan along the same trajectory as the X-ray and beta-ray detectors in the first detection equipment group, obtaining the post-coated electrode areal density corresponding to each ray type, and send it to the host computer. The host computer converts the post-coated electrode areal density corresponding to each ray type into the total weight corresponding to each ray type and displays it. The host computer determines the difference between the total weight corresponding to each ray type and the substrate weight as the coating weight of the target layer material corresponding to each ray type. Then, the host computer displays the coating weight of each layer material and the preset weight range, and determines whether the coating weight exceeds the range. If so, the host computer issues an early warning and sends the coating weight data to the intelligent adjustment controller of the coating equipment. The intelligent adjustment controller adjusts the coating parameters of the corresponding material layer. It then determines whether the early warning has been cleared: if not, the coating weight is manually confirmed and the coating parameters of the corresponding material layer are adjusted; if the warning has been cleared, coating production continues until production is completed.

[0237] Figure 8 This is a schematic diagram illustrating the coating weight detection process of the coating system provided in this embodiment. (Reference) Figure 8This diagram illustrates the inspection process of the electrode substrate 10 during production, passing through the first inspection equipment group 01 and the second inspection equipment group 02. In the electrode transport direction, the uncoated substrate 10 first passes through the first inspection equipment group 01, where X-rays and beta rays are emitted from corresponding radiation sources, pass through the substrate 10, and are received by the detector below. By measuring the incident and transmitted radiation intensities, the areal density of the substrate 10 under X-rays and beta rays is calculated and further converted into the weight of the substrate 10. Subsequently, the substrate 10 enters the first coating equipment 05, where a double-layer material 13 is coated on the same surface, forming a double-layer material structure. After coating, the electrode continues to be transported to the second inspection equipment group 02, where it is again inspected sequentially by X-rays and beta rays. Here, the rays must penetrate the double-layer material structure to obtain the areal density of the coated electrode corresponding to each type of ray, which is then converted into the total weight. Since the first detection equipment group 01 and the second detection equipment group 02 use the same type of radiation and perform the same trajectory scanning on the electrode sheet, precise matching of the surface density of the substrate 10 and the surface density of the coated electrode sheet at the same position can be achieved. The host computer system subtracts the weight of the substrate 10 from the total weight corresponding to each radiation type to obtain the coating weight of the corresponding target layer material, realizing non-contact, online, and real-time detection of the coating weight of each single layer material in double-layer coating.

[0238] Figure 9 This is a schematic diagram of scanning trajectory synchronization in the coating system provided in this application embodiment. (Reference) Figure 9 The electrode 14 is transported horizontally. The forward scanning direction of the detection equipment is vertically downward, and the reverse scanning direction is vertically upward. The four scanning starting points 15 from left to right correspond to the X-ray and beta-ray detection devices in the first detection device group, and the X-ray and beta-ray detection devices in the second detection device group, respectively. Similarly, the four scanning ending points 16 from left to right correspond to the X-ray and beta-ray detection devices in the first detection device group, and the X-ray and beta-ray detection devices in the second detection device group, respectively. During the transport of the electrode 14, the scanning starting points 15 of each detection device are located on the same side of the electrode 14, and the distance from the upper boundary of the electrode 14 is always D. The scanning ending points 16 of each detection device are located on the other side of the electrode 14, and the distance from the lower boundary of the electrode 14 is always D1, ensuring that the scanning area is aligned in the width direction of the electrode 14 and maintaining a consistent scanning path.

[0239] Figure 10 This is a schematic diagram of a coated electrode sheet provided as an embodiment of this application. (Reference) Figure 10Taking the coating of a double-layer material on the first surface of an electrode substrate as an example, the electrode includes a substrate 10, on which a first layer of material 11 and a second layer of material 12 are sequentially coated to form a multi-layer coating system. This schematic diagram illustrates the cross-sectional structure of the electrode under the double-layer coating process. It is understood that the coating thicknesses of the substrate 10, the first layer of material 11, and the second layer of material 12 are merely illustrative and are not limited in this application.

[0240] Figure 11 This is a schematic diagram of the overall layout of another coating system provided in an embodiment of this application. (Reference) Figure 11 The system, arranged sequentially along the electrode conveying direction, includes an unwinding device, a first inspection equipment group 01, a first coating equipment 05, a first drying equipment 06, a second inspection equipment group 02, a flipping mechanism 17, a third inspection equipment group 18, a second coating equipment 20, a second drying equipment 21, a fourth inspection equipment group 19, and a winding device, enabling a complete double-sided multi-layer coating process. Specifically, the electrode substrate is released from the unwinding end and conveyed to the first inspection equipment group 01 via the electrode conveying equipment for detecting the areal density of the substrate before coating; it then enters the first coating equipment 05, where multiple layers of material are sequentially coated on the first surface of the substrate; the coated electrode is dried by the first drying equipment 06; and finally, the second inspection equipment group 02 detects the areal density of the coated electrode to obtain the areal density of the coated electrode. Next, the electrode sheet enters the flipping mechanism 17, thereby flipping its surface so that the original second surface faces upward. After flipping, the electrode sheet's surface density, i.e., the total surface density of the substrate and the first surface coating, is detected by the third detection equipment group 18. Subsequently, it enters the second coating equipment 20, where multiple layers of material are coated again on the second surface. After drying by the second drying equipment 21, the surface density of the electrode sheet after the second coating is detected by the fourth detection equipment group 19 to obtain the surface density of the electrode sheet after the second coating. This layout realizes continuous and automated production of the electrode sheet from unwinding to rewinding, supporting precise coating and online quality monitoring of double-sided multilayer materials.

[0241] Furthermore, this application also proposes an electrode coating weight detection device, which includes: a memory, a processor, and an electrode coating weight detection program stored in the memory and running on the processor. The electrode coating weight detection program is configured to implement the steps of the electrode coating weight detection method described above.

[0242] Furthermore, this application also proposes a storage medium storing an electrode coating weight detection program, which, when executed by a processor, implements the steps of the electrode coating weight detection method described above.

[0243] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this application. In practical applications, those skilled in the art can select some or all of it to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0244] In addition, for technical details not described in detail in this embodiment, please refer to the electrode coating weight detection method provided in any embodiment of this application, which will not be repeated here.

[0245] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for detecting the weight of electrode coatings, characterized in that, The method includes: The surface density of the electrode substrate is detected by the first detection equipment group to determine the surface density of the substrate corresponding to multiple ray types. When the first surface of the electrode substrate is coated with multiple layers of material, the surface density of the coated electrode is detected by the second detection equipment group to determine the surface density of the coated electrode corresponding to each of the multiple ray types. For each type of radiation, the weight of the substrate and the total weight after coating are determined based on the corresponding substrate surface density and the electrode surface density after coating, under the preset detection area. The difference between the total weight corresponding to each ray type and the weight of the substrate is determined as the coating weight of the target layer material corresponding to each ray type, wherein the target layer material corresponding to each ray type is the layer material with the highest mass absorption coefficient for the ray type in the multilayer material; Specifically, for each type of radiation, determining the substrate weight and the total weight after coating within a preset detection area based on the corresponding substrate areal density and the electrode areal density after coating includes: For any type of radiation, the product of the corresponding substrate surface density and the coated electrode surface density with the preset detection area is used as the substrate weight measurement value and the total weight measurement value after coating. Based on the mapping relationship between the measured value and the true value corresponding to the ray type, the measured value of the substrate weight and the measured value of the total weight are corrected to obtain the substrate weight and the total weight after coating corresponding to the ray type.

2. The method as described in claim 1, characterized in that, The step of detecting the surface density of the electrode substrate using the first detection equipment group to determine the surface density of the substrate corresponding to multiple radiation types includes: For any one of the first detection equipment groups, the incident radiation intensity and transmitted radiation intensity of the electrode substrate are collected by the detection equipment. Based on the incident and transmitted radiation intensity of the electrode substrate and the sample mass absorption coefficient, the substrate surface density corresponding to the radiation type of the detection device is determined.

3. The method as described in claim 2, characterized in that, Before acquiring the incident radiation intensity and transmitted radiation intensity of the electrode substrate through any of the detection devices in the first detection device group, the method further includes: The detection equipment is used to collect the incident radiation intensity and transmitted radiation intensity of standard samples. The mass absorption coefficient of the sample is determined based on the incident radiation intensity, transmitted radiation intensity, and areal density of the standard sample.

4. The method as described in claim 2, characterized in that, The step of performing areal density testing on the coated electrode using the second testing equipment group to determine the areal density of the coated electrode corresponding to each of the multiple ray types includes: For any of the detection devices in the second detection device group, the incident radiation intensity and transmitted radiation intensity of the coated electrode are collected by the detection device. Based on the incident and transmitted radiation intensity of the coated electrode and the sample mass absorption coefficient, the surface density of the coated electrode corresponding to the radiation type of the detection device is determined.

5. The method as described in claim 1, characterized in that, Before determining the surface density of the electrode substrate corresponding to multiple radiation types by detecting the surface density of the electrode substrate using the first detection equipment group, the method further includes: For any type of radiation, the average areal density of the electrode substrate is obtained by the detection device corresponding to the radiation type in the first detection device group, and then converted into the average weight measurement value. Multiple substrate samples were obtained and weighed at the areal density detection location of the electrode substrate to determine the average actual weight. Based on the average weight measurement and the average actual weight of the electrode substrate, the mapping relationship between the measured value and the true value of the substrate weight is determined.

6. The method as described in claim 1, characterized in that, Before determining the surface density of the electrode substrate corresponding to multiple radiation types by detecting the surface density of the electrode substrate using the first detection equipment group, the method further includes: For any type of ray, a target layer material corresponding to the type of ray is coated on the electrode substrate with the target coating parameters to obtain the target electrode segment; The average surface density of the target pole segment is obtained by the detection device corresponding to the type of radiation in the second detection device group, and then converted into the average weight measurement value. Multiple electrode samples were obtained and weighed at the areal density detection location of the target electrode segment to determine the average actual weight. Based on the average weight measurement of the target pole segment and the average actual weight, the mapping relationship between the measured value and the true value of the total weight is determined.

7. The method as described in claim 6, characterized in that, The determination of the mapping relationship between the measured value and the true value of the total weight based on the average weight measurement of the target pole segment and the average actual weight includes: The target coating parameters are changed at least once to recoat the electrode substrate to obtain a new target electrode segment, and the average weight measurement value and the average actual weight value are obtained for the new target electrode segment; Based on the average weight measurement and the average actual weight corresponding to multiple target coating parameters, the mapping relationship between the measured value and the true value of the total weight is determined.

8. The method according to any one of claims 1-7, characterized in that, The step of performing areal density testing on the coated electrode using the second testing equipment group to determine the areal density of the coated electrode corresponding to each of the multiple ray types includes: The coated electrode is scanned along the same trajectory as the electrode substrate by the second detection equipment group. Based on the scanning results, the surface density of the coated electrode is determined one-to-one with the detection location of the substrate surface density corresponding to each type of radiation.

9. The method as described in claim 8, characterized in that, The step of scanning the coated electrode substrate using the second detection equipment group along the same trajectory as the first detection equipment group includes: In response to the first device in the first detection device group starting a scanning operation, the electrode tape length is accumulated. The first device is any device in the first detection device group. When the length of the electrode strip is equal to the target distance, the second device is triggered to start the scanning operation. The second device is the device in the second detection device group with the same X-ray type as the first device. The target distance is the distance between the first device and the second device. The distances between the scanning start and end points of the second device and the lateral edge of the electrode are controlled to be consistent with the corresponding distances when the first device is scanning.

10. The method according to any one of claims 1-7, characterized in that, After determining the difference between the total weight corresponding to each ray type and the weight of the substrate as the coating weight of the target layer material corresponding to each ray type, the method further includes: Compare the coating weight of each target layer material with the corresponding preset weight range; If the coating weight exceeds the preset weight range, adjust the coating parameters of the corresponding material layer.

11. The method according to any one of claims 1-7, characterized in that, After determining the difference between the total weight corresponding to each ray type and the weight of the substrate as the coating weight of the target layer material corresponding to each ray type, the method further includes: The coated electrode sheet is then flipped over. The surface density of the electrode sheet after surface flipping is detected by the third detection equipment group to determine the surface density of the flipped electrode sheet corresponding to multiple ray types. The surface density of the flipped electrode sheet is the composite surface density of the electrode sheet substrate and the coated material. When the second surface of the electrode is coated with multiple layers of material, the surface density of the electrode after secondary coating is detected by the fourth detection equipment group to determine the surface density of the electrode after secondary coating corresponding to the multiple ray types. Based on the surface density of the flipped electrode and the surface density of the electrode after secondary coating corresponding to each type of ray, the weight of the flipped electrode and the total weight after secondary coating under the preset detection area are determined. The difference between the total weight corresponding to each ray type and the weight of the flipped electrode is determined as the coating weight of the target layer material corresponding to each ray type.

12. A coating system, characterized in that, The system includes: Electrode transport equipment is used to transport electrode substrates along the length of the substrate. The first coating device, located on the electrode transfer device, is used to coat a multilayer material onto the first surface of the electrode substrate. The first testing equipment group, located upstream of the first coating equipment, is used to test the surface density of the electrode substrate and determine the surface density of the substrate corresponding to multiple ray types. The second testing equipment group, located downstream of the first coating equipment, is used to test the surface density of the coated electrode and determine the surface density of the coated electrode corresponding to multiple ray types. The processor, which is communicatively connected to the first detection device group and the second detection device group, is used to determine the weight of the substrate and the total weight after coating under a preset detection area based on the substrate surface density and the electrode surface density after coating for each type of radiation; and to determine the difference between the total weight and the substrate weight for each type of radiation as the coating weight of the target layer material for each type of radiation, wherein the target layer material for each type of radiation is the layer material with the highest mass absorption coefficient for the radiation type among the multilayer materials. The determination of the substrate weight and the total weight after coating based on the substrate surface density and the electrode surface density corresponding to each ray type includes: For any type of radiation, the product of the corresponding substrate surface density and the coated electrode surface density with the preset detection area is used as the substrate weight measurement value and the total weight measurement value after coating. Based on the mapping relationship between the measured value and the true value corresponding to the ray type, the measured value of the substrate weight and the measured value of the total weight are corrected to obtain the substrate weight and the total weight after coating corresponding to the ray type.

13. The coating system as claimed in claim 12, characterized in that, The system also includes: The third testing equipment group, located downstream of the second testing equipment group, is used to detect the surface density of the electrode sheet after surface flipping, and to determine the surface density of the flipped electrode sheet corresponding to multiple ray types. The surface density of the flipped electrode sheet is the composite surface density of the electrode sheet substrate and the coated material. The second coating device, located downstream of the third testing device group, is used to coat the second surface of the electrode with a multilayer material. The fourth testing equipment group, located downstream of the second coating equipment, is used to test the surface density of the electrode sheet after secondary coating and determine the surface density of the electrode sheet after secondary coating corresponding to the multiple ray types. The processor is further configured to determine the weight of the flipped electrode and the total weight after secondary coating under a preset detection area based on the surface density of the flipped electrode and the surface density of the electrode after secondary coating corresponding to each ray type; and to determine the difference between the total weight and the weight of the flipped electrode corresponding to each ray type as the coating weight of the target layer material corresponding to each ray type.

14. An electrode coating weight detection device, characterized in that, The device includes: a memory, a processor, and an electrode coating weight detection program stored in the memory and running on the processor, the electrode coating weight detection program being configured to implement the steps of the electrode coating weight detection method as described in any one of claims 1 to 11.

15. A storage medium, characterized in that, The storage medium stores an electrode coating weight detection program, which, when executed by a processor, implements the steps of the electrode coating weight detection method as described in any one of claims 1 to 11.

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