Methods, systems and coating testing equipment for measuring the surface density of lithium battery coated electrodes

Abstract

This invention provides a method, system, and coating detection equipment for measuring the areal density of lithium-ion battery coated electrodes, relating to the field of coating detection technology. The method involves emitting X-rays from an X-ray source to penetrate the lithium-ion battery coated electrode. A detector is used to collect the background energy spectrum and sample energy spectrum before and after penetration. The attenuation coefficient curves of characteristic elements (such as Li, Co, and C) in the coating layer are combined with the mean square error results of the background and sample energy spectra to perform full-energy spectrum fitting, ultimately obtaining the optimal areal density value. This solves the radiation safety issues of existing β-ray methods and the interference from material optical properties in infrared methods, achieving non-destructive, high-precision, and simultaneous multi-element measurement of the areal density of lithium-ion battery coated electrodes.

Description

Technical Field

[0001] This invention relates to the field of coating inspection technology, and in particular to a method, system and equipment for measuring the surface density of lithium battery coated electrodes. Background Technology

[0002] In the coating production process of lithium batteries, the uniformity of the areal density of the coated electrodes directly affects the battery's capacity, cycle life, and safety. Current technologies for detecting the areal density of coated electrodes in lithium batteries primarily employ beta-ray and infrared light techniques. The beta-ray method calculates the areal density using the intensity attenuation data of beta rays after penetrating the coating; however, beta rays are radioactive, posing a radiation safety hazard. The infrared light method infers the areal density from differences in infrared light reflectivity; however, infrared reflectivity is easily affected by coating color and surface roughness, making accuracy difficult to guarantee. Furthermore, lithium battery coatings typically contain multiple elements (such as Li and Co in the positive electrode, and C in the negative electrode). Both of the aforementioned techniques largely rely on attenuation information from a single energy point, failing to utilize full-spectrum characteristics, resulting in problems such as multi-element interference and accuracy being affected by noise, making it difficult to simultaneously achieve accurate measurement of the areal density of multiple elements. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a method, system, and coating detection device for measuring the areal density of lithium battery coated electrodes. This method uses an X-ray source to emit X-rays that penetrate the lithium battery coated electrode. A detector is used to collect the background energy spectrum and the sample energy spectrum before and after penetration. The attenuation coefficient curves of characteristic elements (such as Li, Co, C, etc.) in the coating layer are combined, and the mean square error of the background energy spectrum and the sample energy spectrum is used to perform full-energy spectrum fitting. Finally, the optimal areal density value is obtained. This solves the radiation safety problem of the existing β-ray scheme and the interference of the infrared light scheme due to the optical properties of the material. It realizes non-destructive, high-precision, and simultaneous multi-element measurement of the areal density of lithium battery coated electrodes and can solve the above-mentioned problems existing in the prior art.

[0004] In a first aspect, embodiments of the present invention provide a method for measuring the surface density of a lithium battery coated electrode sheet, which is applied to a coating inspection device; wherein the coating inspection device includes at least an X-ray source, a detector, and a stage; the stage is used to place and transport the lithium battery coated electrode sheet to be measured; the X-ray source and the detector are respectively arranged on opposite sides of the lithium battery coated electrode sheet, and the emitting end of the X-ray source and the receiving end of the detector are coaxially aligned.

[0005] The method includes:

[0006] The emission and measurement parameters of the X-ray source are determined based on the model parameters of the lithium battery coated electrode.

[0007] The stage is controlled to transmit the lithium battery coated electrode to the X-ray source via the X-ray path, and the X-ray source is controlled to emit X-rays onto the lithium battery coated electrode using emission parameters;

[0008] The energy spectrum of the sample after the X-ray source penetrates the coated electrode of the lithium battery is obtained by controlling the detector with measurement parameters.

[0009] The elements contained in the coating layer of the lithium battery coated electrode were determined based on the energy spectrum of the sample.

[0010] Obtain the decay coefficient curves corresponding to the elements and the areal density data corresponding to the elements in the lithium battery coated electrode. Construct the theoretical energy spectrum of the lithium battery coated electrode using the product of the decay coefficient curves and the areal density data.

[0011] Based on the mean square error of the theoretical energy spectrum and the sample energy spectrum, the surface density of the lithium battery coated electrode is determined by the surface density data.

[0012] Optionally, before the step of controlling the stage to transmit the lithium-ion battery coated electrode to the X-ray source's beam path, and controlling the X-ray source to emit X-rays onto the lithium-ion battery coated electrode using emission parameters, the method further includes:

[0013] The stage is controlled to transmit the lithium battery coated electrode to the outside of the X-ray optical path, and the X-ray source is controlled to emit X-rays toward the stage using emission parameters.

[0014] The background energy spectrum corresponding to the X-ray source penetrating the stage is obtained by controlling the detector using measurement parameters.

[0015] Optionally, the theoretical energy spectrum of the lithium-ion battery coated electrode can be constructed using the product of the attenuation coefficient curve and the areal density data, including:

[0016] The theoretical energy spectrum of the lithium-ion battery coated electrode is constructed by multiplying the attenuation coefficient curve and the areal density data, along with the background energy spectrum. The theoretical energy spectrum is calculated using the following formula:

[0017] ;

[0018] in, Theoretical energy spectrum; Background energy spectrum; Photon energy; The measurement time is determined by the measurement parameters; For elements The corresponding attenuation coefficient curve; For elements The corresponding areal density data.

[0019] Optionally, the step of determining the areal density of the lithium-ion battery coated electrode based on the mean square error of the theoretical energy spectrum and the sample energy spectrum includes:

[0020] The mean square error (MSE) results of the theoretical energy spectrum and the sample energy spectrum were obtained, and a full-energy spectrum fitting model corresponding to the lithium battery coated electrode was constructed based on the MSE results; wherein, the objective function of the full-energy spectrum fitting model is... for: ; The energy spectrum of the sample;

[0021] With the objective function being minimized, the surface density values ​​corresponding to the elements in the full-energy spectral fitting model are solved using surface density data.

[0022] The areal density of the lithium battery coated electrode is determined using the areal density value.

[0023] Optionally, the surface density values ​​corresponding to the elements in the full-energy spectral fitting model can be solved using surface density data, including:

[0024] Determine the particle swarm corresponding to the surface density data; where the position of each particle in the particle swarm represents a set of candidate surface density values;

[0025] Obtain the optimal values ​​of individual particles and the optimal values ​​of the swarm, and update the velocity and position parameters of each particle based on the optimal values ​​of individual particles and the optimal values ​​of the swarm.

[0026] The fitness of each particle is obtained based on the mean square error result. When the fitness meets the preset fitness threshold condition, the update stops, and the surface density value is determined using the position parameters of the current particle swarm.

[0027] Optionally, the surface density values ​​corresponding to the elements in the full-energy spectral fitting model can be solved using surface density data, including:

[0028] Construct the Jacobian matrix corresponding to the objective function, and determine the damping coefficient corresponding to the Jacobian matrix based on the surface density data;

[0029] Obtain the adjustment amount corresponding to the areal density data, and calculate the error value corresponding to the adjustment amount using the damping coefficient;

[0030] The damping coefficient is updated based on the change in the error value until the damping coefficient meets the preset convergence threshold condition, at which point the update stops, and the surface density value is determined using the current damping coefficient.

[0031] Optionally, the step of determining the elements contained in the coating layer of the lithium-ion battery coated electrode based on the sample energy spectrum includes:

[0032] The characteristic elements contained in the energy spectrum of the sample are determined based on the model parameters of the lithium battery coated electrode.

[0033] Obtain the absorption edge positions corresponding to the feature elements in the sample energy spectrum, and determine the element types corresponding to the feature elements based on the absorption edge positions;

[0034] The elements contained in the coating layer are determined by the element types.

[0035] Optionally, obtain the decay coefficient curves corresponding to the elements and the areal density data corresponding to the elements in the lithium battery coated electrode, including:

[0036] A database of attenuation coefficients corresponding to characteristic elements is established; wherein the characteristic elements include one or more of the elements Li, Co, Ni, Fe, and C.

[0037] Use the attenuation coefficient database to determine the attenuation coefficient curves corresponding to the feature elements;

[0038] The areal density data corresponding to the characteristic elements in the lithium battery coated electrode are determined based on the model parameters.

[0039] In a second aspect, the present invention provides a lithium battery coated electrode surface density measurement system, which is applied to a coating inspection device; wherein the coating inspection device includes at least an X-ray source, a detector and a stage; the stage is used to place and transport the lithium battery coated electrode to be measured; the X-ray source and the detector are respectively arranged on opposite sides of the lithium battery coated electrode, and the emitting end of the X-ray source and the receiving end of the detector are coaxially aligned.

[0040] The system includes:

[0041] The initialization parameter acquisition module is used to determine the emission parameters and measurement parameters of the X-ray source based on the model parameters of the lithium battery coated electrode.

[0042] The X-ray emission control module is used to control the beam path of the stage to transmit the lithium battery coated electrode to the X-ray source, and to control the X-ray source to emit X-rays onto the lithium battery coated electrode using emission parameters.

[0043] The sample energy spectrum acquisition module is used to control the detector with measurement parameters to acquire the sample energy spectrum corresponding to the X-ray source penetrating the lithium battery coated electrode sheet;

[0044] The coating layer element acquisition module is used to determine the elements contained in the coating layer of the lithium battery coated electrode based on the sample energy spectrum.

[0045] The theoretical energy spectrum acquisition module is used to acquire the decay coefficient curves corresponding to the elements and the areal density data corresponding to the elements in the lithium battery coated electrode. The theoretical energy spectrum of the lithium battery coated electrode is constructed by using the product of the decay coefficient curves and the areal density data.

[0046] The areal density measurement and calculation module is used to determine the areal density of the lithium battery coated electrode based on the mean square error results of the theoretical energy spectrum and the sample energy spectrum.

[0047] Thirdly, embodiments of the present invention also provide a coating inspection device, which includes at least an X-ray source, a detector, a stage, and a control unit; the control unit is connected to the X-ray source, the detector, and the stage; the stage is used to place and transport the lithium battery coated electrode to be measured; the X-ray source and the detector are respectively arranged on opposite sides of the lithium battery coated electrode, and the emitting end of the X-ray source and the receiving end of the detector are coaxially aligned.

[0048] The control unit includes a processor and a memory, the memory storing computer-executable instructions that can be executed by the processor, and the processor executing the computer-executable instructions to implement the steps of the lithium battery coated electrode surface density measurement method provided in the first aspect.

[0049] This invention provides a method, system, and coating inspection device for measuring the areal density of lithium-ion battery coated electrodes. The coating inspection device includes at least an X-ray source, a detector, and a stage. The stage is used to place and transport the lithium-ion battery coated electrode to be measured. The X-ray source and detector are respectively positioned on opposite sides of the lithium-ion battery coated electrode, with the emitting end of the X-ray source and the receiving end of the detector coaxially aligned. In the process of detecting the areal density of the lithium-ion battery coated electrode, the method first determines the emission parameters and measurement parameters of the X-ray source based on the model parameters of the lithium-ion battery coated electrode; then, it controls the stage to transport the lithium-ion battery coated electrode to the X-ray source. The X-ray source is controlled by emission parameters to emit X-rays onto the lithium-ion battery coated electrode. Then, measurement parameters are used to control the detector to obtain the energy spectrum of the sample after the X-ray source penetrates the lithium-ion battery coated electrode. The elements contained in the coating layer of the lithium-ion battery coated electrode are then determined based on the sample energy spectrum. Subsequently, the attenuation coefficient curves corresponding to the elements and the areal density data corresponding to the elements in the lithium-ion battery coated electrode are obtained. The theoretical energy spectrum of the lithium-ion battery coated electrode is constructed using the product of the attenuation coefficient curves and the areal density data. Finally, based on the mean square error between the theoretical energy spectrum and the sample energy spectrum, the areal density of the lithium-ion battery coated electrode is determined using the areal density data. This method uses an X-ray source to emit X-rays that penetrate the coated electrode of a lithium battery. A detector is used to collect the background energy spectrum and the sample energy spectrum before and after penetration. The attenuation coefficient curves of characteristic elements (such as Li, Co, C, etc.) in the coating layer are combined with the mean square error of the background energy spectrum and the sample energy spectrum to perform full-energy spectrum fitting, and finally obtain the optimal areal density value. This solves the radiation safety problem of the existing β-ray method and the problem of interference from the optical properties of materials in the infrared method. It realizes non-destructive, high-precision, and simultaneous multi-element measurement of the areal density of coated electrode of lithium battery.

[0050] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0051] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0052] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0053] Figure 1 A flowchart of a method for measuring the surface density of coated electrode sheets in lithium batteries, provided in an embodiment of the present invention;

[0054] Figure 2 This is a flowchart before step S102 in a lithium battery coated electrode surface density measurement method provided in an embodiment of the present invention;

[0055] Figure 3 This is a flowchart of step S106 in a lithium battery coated electrode surface density measurement method provided in an embodiment of the present invention;

[0056] Figure 4 In step S302 of the lithium battery coated electrode surface density measurement method provided in this embodiment of the invention, there is a flowchart of solving the surface density values ​​corresponding to the elements in the full-energy spectrum fitting model by using surface density data.

[0057] Figure 5 In step S302 of another lithium battery coated electrode surface density measurement method provided in this embodiment of the invention, there is a flowchart of solving the surface density values ​​corresponding to the elements in the full-energy spectrum fitting model by using surface density data.

[0058] Figure 6 This is a flowchart of step S104 in a lithium battery coated electrode surface density measurement method provided in an embodiment of the present invention;

[0059] Figure 7 In step S105 of the lithium battery coated electrode surface density measurement method provided in this embodiment of the invention, a flowchart is used to obtain the attenuation coefficient curve corresponding to the element and the surface density data corresponding to the element in the lithium battery coated electrode.

[0060] Figure 8 This is a schematic diagram of a lithium battery coated electrode surface density measurement system provided in an embodiment of the present invention;

[0061] Figure 9 This is a schematic diagram of the control unit in a coating inspection device provided in an embodiment of the present invention.

[0062] icon:

[0063] 810 - Initialization parameter acquisition module; 820 - X-ray emission control module; 830 - Sample energy spectrum acquisition module; 840 - Coating layer element acquisition module; 850 - Theoretical energy spectrum acquisition module; 860 - Areal density measurement and calculation module;

[0064] 101 - Processor; 102 - Memory; 103 - Bus; 104 - Communication interface. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0066] To facilitate understanding of this embodiment, a method for measuring the areal density of lithium-ion battery coated electrodes disclosed in this invention will first be described in detail. Specifically, this method is applied to a coating inspection device; wherein, the coating inspection device includes at least an X-ray source, a detector, and a stage; the stage is used to place and transport the lithium-ion battery coated electrode to be measured; the X-ray source and the detector are respectively arranged on opposite sides of the lithium-ion battery coated electrode, and the emitting end of the X-ray source and the receiving end of the detector are coaxially aligned.

[0067] Based on this, in the process of detecting the areal density of coated electrodes in lithium batteries, this method is as follows: Figure 1 As shown, it includes:

[0068] Step S101: Determine the emission parameters and measurement parameters of the X-ray source based on the model parameters of the lithium battery coated electrode.

[0069] First, based on the specific model parameters of the lithium battery coated electrode to be tested (such as the preset coating material type, substrate characteristics, etc.), the emission parameters of the X-ray source (such as radiation intensity, tube voltage, tube current, etc.) and the measurement parameters of the detector (such as sampling frequency, measurement time, etc.) are determined in advance. This step provides a suitable equipment operating benchmark for subsequent testing, ensuring that the radiation emission and signal acquisition can accurately match the electrode characteristics.

[0070] Step S102: Control the stage to transmit the lithium battery coated electrode to the X-ray source's optical path, and use the emission parameters to control the X-ray source to emit X-rays onto the lithium battery coated electrode.

[0071] The stage is controlled to smoothly transport the lithium battery coated electrode sheet into the X-ray source's beam path according to a preset path, ensuring that the area of ​​the electrode sheet to be inspected is accurately within the X-ray irradiation range. Subsequently, according to the emission parameters determined in step S101, the X-ray source is controlled to emit X-rays towards the electrode sheet, and the rays will penetrate the substrate and coating layer of the electrode sheet.

[0072] Step S103: Use measurement parameters to control the detector to obtain the energy spectrum of the sample after the X-ray source penetrates the lithium battery coated electrode.

[0073] While the X-rays penetrate the electrode, the detector is activated according to the measurement parameters set in step S101 (such as sampling frequency and measurement time) to receive and record the energy distribution of the X-rays after penetrating the electrode, ultimately obtaining the corresponding sample energy spectrum. This energy spectrum contains information on the energy attenuation after the X-rays interact with the various components of the electrode.

[0074] Step S104: Determine the elements contained in the coating layer of the lithium battery coated electrode based on the sample energy spectrum.

[0075] The energy spectrum of the sample obtained in step S103 is analyzed. By analyzing the position and intensity of characteristic peaks in the energy spectrum, key elements (such as active material elements like lithium, cobalt, nickel, and manganese, as well as possible additive elements) contained in the coating layer of the lithium battery coated electrode are identified. This step identifies the core analytical objects for subsequent areal density calculations.

[0076] Step S105: Obtain the decay coefficient curves corresponding to the elements and the areal density data corresponding to the elements in the lithium battery coated electrode. Construct the theoretical energy spectrum of the lithium battery coated electrode using the product of the decay coefficient curves and the areal density data.

[0077] For each element identified in step S104, its corresponding attenuation coefficient curve can be retrieved from a preset database (this curve reflects the relationship between the element's attenuation ability for X-rays of different energies and the energy). Simultaneously, the possible areal density data range of these elements in the electrode is obtained (as the initial calculation basis). The attenuation coefficient curve of each element is multiplied by its corresponding areal density data, and then the theoretical energy spectrum of the electrode is constructed through superposition calculation; that is, the energy spectrum that should appear after X-ray penetration if the electrode is composed of these elements at a specific areal density.

[0078] Step S106: Based on the mean square error results of the theoretical energy spectrum and the sample energy spectrum, determine the surface density corresponding to the lithium battery coated electrode through the surface density data.

[0079] Compare the sample energy spectrum obtained in step S103 with the theoretical energy spectrum constructed in step S105, and calculate the mean square error between the two. By adjusting the areal density data of the elements and repeatedly calculating the theoretical energy spectrum, the mean square error is gradually reduced until the error reaches the minimum threshold. The areal density data at this point is the actual areal density of the lithium battery coated electrode. This step uses energy spectrum matching verification to achieve accurate reverse estimation of the areal density.

[0080] Optionally, before step S102, which controls the stage to transport the lithium-ion battery coated electrode to the X-ray source via the X-ray optical path, and controls the X-ray source to emit X-rays onto the lithium-ion battery coated electrode using emission parameters, as follows: Figure 2 As shown, the method also includes:

[0081] Step S201: Control the stage to transmit the lithium battery coated electrode to outside the X-ray optical path, and use the emission parameters to control the X-ray source to emit X-rays to the stage.

[0082] Before formally inspecting the lithium battery coated electrodes, the stage is first controlled to transport the electrodes outside the X-ray source's beam path (i.e., ensuring the electrodes do not block the rays), making the stage itself the object of X-ray irradiation. Then, according to the emission parameters determined in step S101 (such as ray intensity and tube voltage), the X-ray source is controlled to emit X-rays towards the stage. At this point, the rays only penetrate the stage itself (without passing through the electrodes). The purpose of this step is to separately obtain data on the attenuation effect of the stage on the X-rays, eliminating its interference with subsequent electrode inspection.

[0083] Step S202: Use measurement parameters to control the detector to obtain the background energy spectrum corresponding to the X-ray source penetrating the stage.

[0084] During the X-ray penetration of the stage, the detector is controlled to start working according to the measurement parameters set in step S101 (such as sampling frequency, energy resolution, etc.), receiving and recording the energy distribution of X-rays after penetrating the stage, and finally obtaining the corresponding background energy spectrum. This energy spectrum reflects the attenuation of X-ray energy due to factors such as stage material and thickness. It can be used as benchmark data for analyzing sample energy spectra from electrodes. To eliminate interference from the stage, the accuracy of areal density measurement is improved. Optionally, the theoretical energy spectrum of the lithium-ion battery coated electrode can be constructed using the product of the attenuation coefficient curve and the areal density data, including:

[0085] The theoretical energy spectrum of the lithium-ion battery coated electrode is constructed by multiplying the attenuation coefficient curve and the areal density data, along with the background energy spectrum. The theoretical energy spectrum is calculated using the following formula:

[0086] ;

[0087] in, Theoretical energy spectrum; Background energy spectrum; Photon energy; The measurement time is determined by the measurement parameters; For elements The corresponding attenuation coefficient curve; For elements The corresponding areal density data.

[0088] Optionally, step S106, which determines the areal density of the lithium-ion battery coated electrode based on the mean square error of the theoretical energy spectrum and the sample energy spectrum, using areal density data, is as follows: Figure 3 As shown, it includes:

[0089] Step S301: Obtain the mean square error results of the theoretical energy spectrum and the sample energy spectrum, and construct the full-energy spectrum fitting model corresponding to the lithium battery coated electrode based on the mean square error results.

[0090] First, the mean square error between the theoretical energy spectrum obtained in step S105 and the sample energy spectrum obtained in step S103 is calculated. This error reflects the degree of difference in energy distribution between the two. Based on this mean square error result, a full-energy spectrum fitting model suitable for this lithium-ion battery coated electrode is constructed. This model essentially quantifies the difference between the theoretical energy spectrum and the sample energy spectrum through mathematical relationships, and at the same time correlates the areal density parameters of each element in the coating layer to form a mapping relationship of "area density-energy spectrum difference", providing a mathematical framework for subsequent areal density calculation.

[0091] Step S302: With the goal of minimizing the output value of the objective function of the full-energy spectrum fitting model, solve for the surface density values ​​corresponding to the elements in the full-energy spectrum fitting model using surface density data.

[0092] The optimization objective is to minimize the output value of the objective function in the full-energy spectrum fitting model (i.e., to minimize the difference between the theoretical energy spectrum and the sample energy spectrum). This is achieved through iterative calculations by adjusting the areal density data corresponding to each element in the model. Specifically, the areal density parameters of each element are continuously corrected, the theoretical energy spectrum is regenerated and compared with the sample energy spectrum, until the output value of the objective function (e.g., mean square error) reaches a minimum threshold. The areal density values ​​obtained at this point represent the actual areal density of the corresponding element in the electrode coating layer. This step utilizes the idea of ​​optimization algorithms, iteratively approximating the true value to ensure the accuracy of the results.

[0093] Step S303: Determine the areal density corresponding to the lithium battery coated electrode using the areal density value.

[0094] The summarizing steps in S302 involve calculating the areal density values ​​of each element. Based on the composition of the electrode coating layer (such as the ratio of elements or the total mass percentage), the overall areal density of the lithium-ion battery coated electrode can be calculated. For example, if the coating layer is mainly composed of elements such as lithium, cobalt, and nickel, the areal densities of these elements can be added together (or summed according to specific weights) to obtain the total mass of the coating layer per unit area of ​​the electrode, which is the final areal density result. This step completes the integration of the areal density from the elemental level to the overall electrode, forming the final detection conclusion.

[0095] Among them, the objective function of the full-energy spectrum fitting model for: ; This is the energy spectrum of the sample. Combined with the above formula... The theoretical energy spectrum can also be expressed as follows: Based on the objective of minimizing the output value of the objective function of the above-mentioned full-spectrum fitting model, the particle swarm optimization algorithm or the Levenberg-Marquardt (LM) algorithm can be used to achieve this.

[0096] Optionally, the surface density values ​​corresponding to the elements in the full-energy spectrum fitting model can be solved using surface density data, such as... Figure 4 As shown, it includes:

[0097] Step S401: Determine the particle swarm corresponding to the surface density data; wherein, the position of each particle in the particle swarm represents a set of candidate surface density values.

[0098] When using the particle swarm optimization algorithm to solve for elemental areal density, the areal density data is first transformed into a "particle swarm" in the algorithm. The position of each particle is assigned a physical meaning, i.e., a set of candidate elemental areal density values. The size of the particle swarm (number of particles) and the initial position range need to be set in conjunction with the electrode process parameters (such as the designed areal density range) to ensure that the candidate values ​​cover the actual possible areal density range, providing sufficient search space for subsequent optimization.

[0099] Step S402: Obtain the optimal values ​​of individual particles and the optimal values ​​of the swarm, and update the velocity and position parameters of each particle based on the optimal values ​​of individual particles and the optimal values ​​of the swarm.

[0100] The particle swarm is evaluated by calculating the "particle optimal value" (the position parameter that minimizes the mean square error between the theoretical and sample energy spectra since the particle's initial position) and the "population optimal value" (the position parameter of the particle with the smallest current error in the entire swarm). Then, based on these two optimal values, the velocity parameters (which determine the direction and magnitude of position changes) and position parameters (i.e., corrections to candidate areal density values) of each particle are adjusted according to the particle swarm optimization algorithm's update rules (typically including parameters such as inertia weights, individual learning factors, and social learning factors). This process guides the particle swarm towards regions with smaller errors by simulating information sharing and cooperation among individuals within the swarm.

[0101] Specifically, the velocity and position parameters are calculated using the following formulas:

[0102]

[0103]

[0104] in, For inertial weights, , t is the learning factor, pbest is the particle's optimal value, gbest is the swarm's optimal value; t is the particle's motion time.

[0105] Step S403: Obtain the fitness of each particle based on the mean square error result. Stop updating when the fitness meets the preset fitness threshold condition, and determine the surface density value using the position parameters of the current particle swarm.

[0106] The mean square error between the theoretical energy spectrum and the sample energy spectrum is used as the "fitness" of each particle (the smaller the error, the higher the fitness), and the particle positions are continuously updated iteratively. Updates stop when the fitness of the best particle in the particle swarm reaches a preset threshold, or when the number of iterations reaches its maximum. At this point, the position parameters of the particle with the best fitness in the current particle swarm are the areal density values ​​corresponding to each element. This step converges quickly to the optimal solution through heuristic search, balancing computational efficiency and result accuracy, and is particularly suitable for collaborative solutions of multi-element areal densities.

[0107] Optionally, the surface density values ​​corresponding to the elements in the full-energy spectrum fitting model can be solved using surface density data, such as... Figure 5 As shown, it includes:

[0108] Step S501: Construct the Jacobian matrix corresponding to the objective function, and determine the damping coefficient corresponding to the Jacobian matrix based on the surface density data.

[0109] First, for the objective function of the full-energy spectrum fitting model (i.e., the mean square error function between the theoretical energy spectrum and the sample energy spectrum), its corresponding Jacobian matrix J is constructed. The elements of the Jacobian matrix represent the influence of changes in the surface density parameter on the energy spectrum error, reflect the partial derivatives of the objective function with respect to each element's surface density parameter, and intuitively demonstrate the sensitivity of the influence of changes in each surface density parameter on the energy spectrum error.

[0110] Simultaneously, based on the initial areal density data (such as a preset range of element areal densities or empirical values), the damping coefficient corresponding to the Jacobian matrix is ​​determined. The damping coefficient is a core parameter of the LM algorithm, and its role is to balance the characteristics of "gradient descent" (fast convergence) and "Gauss-Newton" (precise approximation) during the iteration process: the initial value of the damping coefficient needs to be adjusted according to the complexity of the electrode element composition to ensure stability in the early stage of iteration.

[0111] Step S502: Obtain the adjustment amount corresponding to the areal density data, and calculate the error value corresponding to the adjustment amount using the damping coefficient.

[0112] Based on the current areal density data, the adjustment amount (i.e., parameter correction value) of the areal density of each element is calculated. This adjustment amount is jointly determined by the Jacobian matrix, the objective function error value, and the damping coefficient. Subsequently, this adjustment amount is substituted into the objective function, and the damping coefficient is used to constrain the adjustment amount. The corresponding error value after adjustment is calculated (i.e., the new mean square error between the theoretical energy spectrum and the sample energy spectrum after correcting the areal density parameters). This step limits the magnitude of the adjustment amount by the damping coefficient to avoid iterative divergence due to excessive parameter changes, and at the same time, the error value is used to evaluate the effectiveness of the current adjustment direction.

[0113] The above process can be achieved through the following formula: ( Where e is the error vector and I is the identity matrix. The damping coefficient; For adjustment purposes;

[0114] Step S503: Update the damping coefficient according to the change in the error value until the damping coefficient meets the preset convergence threshold condition, and then stop updating. Use the current damping coefficient to determine the surface density value.

[0115] Repeat the above adjustment and update process; if the error decreases, then reduce the value. (Gauss-Newton model), otherwise increase (Gradient descent silent mode) until the damping coefficient converges to a preset threshold after iteration. The corresponding areal density parameter at this point is the optimal solution, thus determining the areal density value of each element in the coating layer of the lithium battery coated electrode.

[0116] Optionally, step S104, which determines the elements contained in the coating layer of the lithium-ion battery coated electrode based on the sample energy spectrum, is as follows: Figure 6 As shown, it includes:

[0117] Step S601: Determine the characteristic elements contained in the energy spectrum of the sample based on the model parameters of the lithium battery coated electrode.

[0118] First, based on the model parameters of the lithium-ion battery coated electrode (such as known coating formulations and cathode / anode material types, such as common ternary materials and lithium iron phosphate for cathodes, and graphite for anodes), determine the range of characteristic elements that may be included in the coating layer of this type of electrode (for example, ternary material electrodes may involve lithium, cobalt, nickel, and manganese, while lithium iron phosphate electrodes may involve lithium, iron, and phosphorus). This step narrows down the target range of elemental analysis by using model parameters, avoiding invalid identification of irrelevant elements and improving the efficiency of subsequent analysis.

[0119] Step S602: Obtain the absorption edge position corresponding to the feature element in the sample energy spectrum, and determine the element type corresponding to the feature element based on the absorption edge position.

[0120] For the characteristic element range locked in step S601, the "absorption edge position" corresponding to each element is located in the sample energy spectrum acquired by the detector. When the X-ray energy reaches a certain specific value, the inner-shell electrons of the element atoms will absorb the X-ray energy and undergo a transition, resulting in a significant abrupt decay in the energy spectrum at that energy point (i.e., absorption edge). The absorption edge positions of different elements have unique energy characteristics (e.g., the K absorption edge of iron (Fe) is about 7.11 keV, and the K absorption edge of cobalt (Co) is about 7.7 keV).

[0121] By comparing the detected absorption edge positions in the sample energy spectrum with a standard absorption edge energy database of known elements, the element type corresponding to that absorption edge can be accurately matched. For example, if a significant absorption edge appears in the energy spectrum around 7.7 keV, it can be determined that the coating layer contains cobalt.

[0122] Step S603: Determine all elements contained in the coating layer using element types.

[0123] In step S602, all element types identified by the absorption edge position are summarized and verified against the material system corresponding to the electrode model parameters (e.g., excluding spurious element signals caused by substrate interference or measurement errors). This process ultimately determines all elements actually contained in the coating layer of the lithium-ion battery electrode. This step ensures the completeness and accuracy of element identification, providing a reliable analytical basis for subsequent calculations of areal density based on element decay characteristics.

[0124] Optionally, obtain the decay coefficient curves corresponding to the elements and the areal density data corresponding to the elements in the lithium battery coated electrode, such as... Figure 7 As shown, it includes:

[0125] Step S701: Determine the attenuation coefficient database corresponding to the feature elements; wherein, the feature elements include one or more of the above elements such as Li, Co, Ni, Fe, and C.

[0126] First, the range of common characteristic elements in the coating layer of lithium-ion battery electrode sheets is defined, mainly including lithium (Li), cobalt (Co), nickel (Ni), iron (Fe), and carbon (C) (these elements are the core components of the positive and negative electrode materials of lithium-ion batteries; for example, ternary materials for the positive electrode contain Co, Ni, and Li, lithium iron phosphate contains Fe, Li, and P, and graphite for the negative electrode contains C). Based on these characteristic elements, a pre-established attenuation coefficient database is invoked. This database stores the attenuation coefficients of different elements at various X-ray energies (i.e., the attenuation ability of a unit thickness of material to X-rays), and the data sources are usually authoritative physical constant handbooks or experimental measurement and calibration results, ensuring the accuracy of the basic data for subsequent analysis. For example, the attenuation coefficient database used in this application comes from Zschornack's "Handbook of X-ray Data".

[0127] Step S702: Use the attenuation coefficient database to determine the attenuation coefficient curve corresponding to the feature element.

[0128] From the attenuation coefficient database determined in step S701, attenuation coefficient curves are extracted for the identified characteristic elements (such as Co, Ni, and Li as determined in step S603). The attenuation coefficient curve is a function curve with X-ray energy on the horizontal axis and attenuation coefficient on the vertical axis, reflecting the attenuation law of a specific element for X-rays of different energies (for example, the attenuation of the same element for low-energy X-rays is usually stronger than that for high-energy X-rays). This step provides a quantitative basis for element-specific attenuation calculations of the energy attenuation after X-rays penetrate the electrode.

[0129] Step S703: Determine the areal density data corresponding to the characteristic elements in the lithium battery coated electrode based on the model parameters.

[0130] Based on the model parameters of the lithium battery coated electrode (such as the designed coating material ratio, nominal areal density range, substrate type, etc.), the areal density data corresponding to each characteristic element in the lithium battery coated electrode is determined. This areal density data will be used for the construction of theoretical energy spectrum and the calculation of mean square error results, which will not be elaborated further.

[0131] As can be seen from the lithium battery coated electrode surface density measurement method mentioned in the above embodiments, this method uses an X-ray source to emit X-rays that penetrate the lithium battery coated electrode, and uses a detector to collect the background energy spectrum and sample energy spectrum before and after penetration, respectively. Combined with the attenuation coefficient curves of characteristic elements (such as Li, Co, C, etc.) in the coating layer, and using the mean square error results of the background energy spectrum and sample energy spectrum to perform full-energy spectrum fitting, the optimal surface density value is finally obtained. This solves the radiation safety problem of the existing β-ray scheme and the problem of interference from the optical properties of materials in the infrared scheme, and realizes non-destructive, high-precision, and multi-element simultaneous measurement of the surface density of lithium battery coated electrodes.

[0132] Corresponding to the lithium battery coated electrode surface density measurement method provided in the foregoing embodiments, this invention provides a lithium battery coated electrode surface density measurement system, which is applied to a coating inspection device; wherein, the coating inspection device includes at least an X-ray source, a detector, and a stage; the stage is used to place and transport the lithium battery coated electrode to be measured; the X-ray source and the detector are respectively arranged on opposite sides of the lithium battery coated electrode, and the emitting end of the X-ray source and the receiving end of the detector are coaxially aligned;

[0133] like Figure 8 As shown, the system includes:

[0134] The initialization parameter acquisition module 810 is used to determine the emission parameters and measurement parameters of the X-ray source based on the model parameters of the lithium battery coated electrode sheet;

[0135] X-ray emission control module 820 is used to control the beam path of the stage to transmit the lithium battery coated electrode to the X-ray source, and to control the X-ray source to emit X-rays to the lithium battery coated electrode using emission parameters.

[0136] The sample energy spectrum acquisition module 830 is used to control the detector to acquire the sample energy spectrum after the X-ray source penetrates the lithium battery coated electrode using measurement parameters.

[0137] The coating layer element acquisition module 840 is used to determine the elements contained in the coating layer of the lithium battery coated electrode based on the sample energy spectrum.

[0138] The theoretical energy spectrum acquisition module 850 is used to acquire the decay coefficient curves corresponding to the elements and the areal density data corresponding to the elements in the lithium battery coated electrode. The theoretical energy spectrum of the lithium battery coated electrode is constructed by using the product of the decay coefficient curves and the areal density data.

[0139] The areal density measurement and calculation module 860 is used to determine the areal density of the lithium battery coated electrode based on the mean square error results of the theoretical energy spectrum and the sample energy spectrum.

[0140] As can be seen from the lithium battery coated electrode surface density measurement system mentioned in the above embodiments, the system emits X-rays from an X-ray source to penetrate the lithium battery coated electrode, and uses a detector to collect the background energy spectrum and sample energy spectrum before and after penetration, respectively. Combining the attenuation coefficient curves of characteristic elements (such as Li, Co, C, etc.) in the coating layer, and using the mean square error results of the background energy spectrum and sample energy spectrum to perform full-energy spectrum fitting, the optimal surface density value is finally obtained. This solves the radiation safety problem of the existing β-ray scheme and the problem of interference from the optical properties of materials in the infrared scheme, and realizes non-destructive, high-precision, and multi-element simultaneous measurement of the surface density of lithium battery coated electrodes.

[0141] The lithium battery coated electrode surface density measurement system provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned lithium battery coated electrode surface density measurement method embodiment. For the sake of brevity, any parts not mentioned in the system embodiment can be referred to the corresponding content in the aforementioned lithium battery coated electrode surface density measurement method embodiment.

[0142] This embodiment also provides a coating inspection device, which includes at least an X-ray source, a detector, a stage, and a control unit; the control unit is connected to the X-ray source, the detector, and the stage; the stage is used to place and transport the lithium battery coated electrode to be measured; the X-ray source and the detector are respectively arranged on opposite sides of the lithium battery coated electrode, and the emitting end of the X-ray source and the receiving end of the detector are coaxially aligned.

[0143] In this specific scenario, the detector is a silicon drift detector; the stage is a three-dimensional moving platform with a movement accuracy of ±1. It supports continuous electrode transmission for online scanning measurement; the X-ray source is a microfocus source, with an adjustable tube voltage range of 0~50kV and an X-ray energy range of 3~17keV, equipped with a focusing capillary to form a 50° focal length. The light spot.

[0144] The structural diagram of the control unit is shown below. Figure 9 As shown, the device includes a processor 101 and a memory 102; wherein, the memory 102 is used to store one or more computer instructions, which are executed by the processor to implement the steps of the above-described lithium battery coated electrode surface density measurement method.

[0145] Figure 9 The coating apparatus shown also includes a bus 103 and a communication interface 104. The processor 101, the communication interface 104, and the memory 102 are connected via the bus 103.

[0146] The memory 102 may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device. The bus 103 may be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 9 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0147] The communication interface 104 is used to connect to at least one user terminal and other network units through a network interface, and to send encapsulated IPv4 packets or IPv4 packets to the user terminal through the network interface.

[0148] Processor 101 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 101 or by instructions in software form. The processor 101 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this disclosure. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this disclosure can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory 102. The processor 101 reads the information in memory 102 and, in conjunction with its hardware, completes the steps of the method described in the foregoing embodiments.

[0149] This invention also provides a storage medium storing a computer program, which, when run by a processor, executes the steps of the lithium battery coated electrode surface density measurement method described in the foregoing embodiments.

[0150] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, devices, and methods can be implemented in other ways. The system embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0151] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0152] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0153] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0154] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for measuring the surface density of coated lithium battery electrodes, characterized in that, The method is applied to a coating detection device; wherein the coating detection device at least comprises an X-ray source, a detector and a stage; the stage is used to place and transport a lithium battery coating pole piece to be measured; the X-ray source and the detector are respectively arranged on the opposite sides of the lithium battery coating pole piece, and the emission end of the X-ray source is coaxially aligned with the receiving end of the detector; The method comprises: determining the emission parameters and the measurement parameters of the X-ray source based on the model parameters of the lithium battery coating pole piece; controlling the stage to transport the lithium battery coating pole piece to the ray optical path of the X-ray source, and controlling the X-ray source to emit X-rays to the lithium battery coating pole piece by using the emission parameters; controlling the detector to obtain the sample energy spectrum corresponding to the X-rays penetrating the lithium battery coating pole piece by using the measurement parameters; determining the elements contained in the coating layer of the lithium battery coating pole piece according to the sample energy spectrum; obtaining the attenuation coefficient curve corresponding to the elements and the area density data corresponding to the elements in the lithium battery coating pole piece, and constructing the theoretical energy spectrum of the lithium battery coating pole piece by using the product of the attenuation coefficient curve and the area density data; determining the area density corresponding to the lithium battery coating pole piece by using the area density data based on the mean square error results of the theoretical energy spectrum and the sample energy spectrum.

2. The method for measuring the surface density of lithium battery coated electrode sheets according to claim 1, characterized in that, Before the step of controlling the stage to transport the lithium battery coating pole piece to the ray optical path of the X-ray source and controlling the X-ray source to emit X-rays to the lithium battery coating pole piece by using the emission parameters, the method further comprises: controlling the stage to transport the lithium battery coating pole piece out of the ray optical path, and controlling the X-ray source to emit X-rays to the stage by using the emission parameters; controlling the detector to obtain the background energy spectrum corresponding to the X-rays penetrating the stage by using the measurement parameters.

3. The method for measuring the surface density of lithium battery coated electrode sheets according to claim 2, characterized in that, Constructing the theoretical energy spectrum of the lithium battery coating pole piece by using the product of the attenuation coefficient curve and the area density data comprises: constructing the theoretical energy spectrum of the lithium battery coating pole piece by using the product of the attenuation coefficient curve and the area density data and the background energy spectrum; wherein the theoretical energy spectrum is calculated by the following formula: ； wherein is the theoretical energy spectrum; is the background energy spectrum; is the photon energy; is the measurement time determined by the measurement parameter; is the element corresponding to the attenuation coefficient curve; is the element corresponding to the surface density data.

4. The method for measuring the surface density of lithium battery coated electrode sheets according to claim 3, characterized in that, The step of determining the area density corresponding to the lithium battery coating pole piece by using the area density data based on the mean square error results of the theoretical energy spectrum and the sample energy spectrum comprises: An error mean square result of the theoretical energy spectrum and the sample energy spectrum is obtained, and a full energy spectrum fitting model corresponding to the lithium battery coated electrode is constructed based on the error mean square result; wherein a target function of the full energy spectrum fitting model is: ; ; is the sample energy spectrum; taking the minimum output value of the objective function as the target, solving the area density value corresponding to the elements in the full energy spectrum fitting model by using the area density data; determining the area density corresponding to the lithium battery coating pole piece by using the area density value.

5. The method for measuring the surface density of lithium battery coated electrode sheets according to claim 4, characterized in that, Solving the area density value corresponding to the elements in the full energy spectrum fitting model by using the area density data comprises: determining the particle group corresponding to the area density data; wherein the position of each particle in the particle group represents a set of candidate area density values; obtaining the particle optimal value and the group optimal value corresponding to the particle group, and updating the speed parameter and the position parameter of each particle according to the particle optimal value and the group optimal value; According to the mean square error result, the fitness of each particle is obtained, and when the fitness meets a preset fitness threshold condition, the updating is stopped, and the area density value is determined by using a current position parameter of the particle swarm.

6. The method for measuring the surface density of lithium battery coated electrode sheets according to claim 4, characterized in that, The area density data is used to solve the area density value of the element in the full energy spectrum fitting model, including: A Jacobian matrix corresponding to the objective function is constructed, and a damping coefficient corresponding to the Jacobian matrix is determined based on the area density data; An adjustment amount corresponding to the area density data is obtained, and an error value corresponding to the adjustment amount is calculated by using the damping coefficient; The damping coefficient is updated according to the change amount corresponding to the error value, and when the damping coefficient meets a preset convergence threshold condition, the updating is stopped, and the area density value is determined by using the current damping coefficient.

7. The method of claim 1, wherein the coating density of the lithium electrode is measured by a method comprising: According to the sample energy spectrum, the step of determining the elements contained in the coating layer of the lithium battery coated pole piece includes: According to the model parameters of the lithium battery coated pole piece, the characteristic elements contained in the sample energy spectrum are determined; The absorption edge position corresponding to the characteristic element in the sample energy spectrum is obtained, and the element type corresponding to the characteristic element is determined according to the absorption edge position; All elements contained in the coating layer are determined by using the element type.

8. The method for measuring the surface density of lithium battery coated electrode sheets according to claim 7, characterized in that, The attenuation coefficient curve corresponding to the element and the area density data corresponding to the element in the lithium battery coated pole piece are obtained, including: A database of attenuation coefficients corresponding to the characteristic elements is determined; wherein the characteristic elements include one or more of Li, Co, Ni, Fe and C; The attenuation coefficient curve corresponding to the characteristic element is determined by using the database of attenuation coefficients; The area density data corresponding to the characteristic element in the lithium battery coated pole piece is determined based on the model parameters.

9. A lithium electrode coated electrode sheet area density measurement system characterized by, The system is applied to a coating detection device; wherein the coating detection device at least includes an X-ray source, a detector and a stage; the stage is used to place and transport the lithium battery coated pole piece to be measured; the X-ray source and the detector are respectively arranged on the opposite sides of the lithium battery coated pole piece, and the emission end of the X-ray source is coaxially aligned with the receiving end of the detector; The system includes: An initialization parameter acquisition module is configured to determine the emission parameters and measurement parameters of the X-ray source based on the model parameters of the lithium battery coated pole piece; An X-ray emission control module is configured to control the stage to transport the lithium battery coated pole piece to the ray light path of the X-ray source, and control the X-ray source to emit X-rays to the lithium battery coated pole piece by using the emission parameters; A sample energy spectrum acquisition module is configured to control the detector to acquire the sample energy spectrum corresponding to the X-ray source penetrating the lithium battery coated pole piece by using the measurement parameters; A coating layer element acquisition module is configured to determine the elements contained in the coating layer of the lithium battery coated pole piece according to the sample energy spectrum; A theoretical energy spectrum acquisition module is configured to acquire the attenuation coefficient curve corresponding to the element and the area density data corresponding to the element in the lithium battery coated pole piece, and construct the theoretical energy spectrum of the lithium battery coated pole piece by using the product of the attenuation coefficient curve and the area density data. The areal density measurement calculation module is configured to determine the areal density of the lithium battery coated electrode based on the mean square error result of the theoretical energy spectrum and the sample energy spectrum and the areal density data.

10. A coating inspection apparatus characterized by comprising: The coating detection device comprises an X-ray source, a detector, a carrier table and a control unit; the control unit is connected with the X-ray source, the detector and the carrier table respectively; the carrier table is used for placing and transmitting the lithium battery coated electrode to be measured; the X-ray source and the detector are arranged on the opposite sides of the lithium battery coated electrode respectively, and the emission end of the X-ray source is coaxially aligned with the receiving end of the detector. The control unit comprises a processor and a memory, the memory stores computer executable instructions capable of being executed by the processor, and the processor executes the computer executable instructions to realize the steps of the lithium battery coated electrode areal density measurement method according to any one of claims 1 to 8.

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