Method and system for controlling the coating and drying process of lithium battery anode

Abstract

This invention discloses a method and system for controlling the drying process of lithium-ion battery anode coating, relating to the field of drying control technology. The method includes: setting a steam regulating component in a drying device; obtaining a lithium-ion battery anode coating substrate; sending the lithium-ion battery anode coating substrate into the drying device to perform a first drying stage; using the steam regulating component to control the steam solvent at a first steam rate to steam treat the lithium-ion battery anode coating substrate; detecting the real-time temperature of the lithium-ion battery anode coating substrate; if the temperature rise rate gradient difference is less than a preset threshold, entering a second drying stage; using the steam regulating component to control the steam solvent at a second steam rate to steam treat the lithium-ion battery anode coating substrate until the lithium-ion battery anode coating substrate is dried. This solves the technical problem of poor drying effect in existing lithium-ion battery anode coating technologies, achieving dynamic optimization control of the drying process through staged adjustment of steam rate, wind speed, and temperature, thereby improving the drying effect.

Description

Technical Field

[0001] This invention relates to the field of drying control technology, specifically to a method and system for controlling the drying process of lithium battery anode coating. Background Technology

[0002] In the manufacturing process of lithium-ion batteries, the negative electrode coating process is one of the key steps determining the quality of the electrode sheet and the performance of the battery. Typically, a slurry containing binders, conductive agents, and solvents is uniformly coated onto the surface of a metal current collector, and a drying process removes the solvent to obtain a stable electrode coating. However, existing drying processes generally rely on a single temperature or airflow adjustment method, lacking coordinated control of the steam and hot air environments. This leads to problems such as uneven drying rates, localized over-drying, or residual solvents during the drying process, which in turn affects the density and uniformity of the coating layer, reducing the cycle stability and safety performance of the electrode sheet. Summary of the Invention

[0003] This application provides a method and system for controlling the coating and drying process of lithium battery anodes, which solves the technical problem of poor coating and drying effect of lithium battery anodes in the prior art.

[0004] A first aspect of this application provides a method for controlling the coating and drying process of a lithium-ion battery negative electrode, the method comprising:

[0005] A steam regulating component is installed in the drying equipment. A lithium-ion battery negative electrode coated substrate is obtained and fed into the drying equipment to perform a first drying stage. The steam regulating component controls the steam solvent at a first steam rate to steam treat the lithium-ion battery negative electrode coated substrate. At the same time, the wind speed regulating component and temperature regulating component of the drying equipment are set to a first wind speed range and a first temperature range. The real-time temperature of the lithium-ion battery negative electrode coated substrate is detected. If the temperature rise rate gradient difference of the real-time temperature is less than a preset threshold, the second drying stage is entered. The steam regulating component controls the steam solvent at a second steam rate to steam treat the lithium-ion battery negative electrode coated substrate. At the same time, the wind speed regulating component and temperature regulating component of the drying equipment are set to a second wind speed range and a second temperature range until the lithium-ion battery negative electrode coated substrate is dried. Wherein, the first steam rate is greater than the second steam rate, the first wind speed range is less than the second wind speed range, and the first temperature range is less than the second temperature range.

[0006] A second aspect of this application provides a control system for the coating and drying process of a lithium-ion battery negative electrode, the system comprising:

[0007] Component Setting Module: A steam regulating component is set in the drying equipment; First Drying Module: Obtains the lithium-ion battery negative electrode coating substrate, sends the lithium-ion battery negative electrode coating substrate into the drying equipment to perform a first drying stage, uses the steam regulating component to control the steam solvent at a first steam rate to steam treat the lithium-ion battery negative electrode coating substrate, and simultaneously keeps the wind speed regulating component and temperature regulating component of the drying equipment within a first wind speed range and a first temperature range; Second Drying Module: Detects the real-time temperature of the lithium-ion battery negative electrode coating substrate, if the temperature rise rate gradient difference of the real-time temperature is less than a preset threshold, enters the second drying stage, uses the steam regulating component to control the steam solvent at a second steam rate to steam treat the lithium-ion battery negative electrode coating substrate, and simultaneously keeps the wind speed regulating component and temperature regulating component of the drying equipment within a second wind speed range and a second temperature range, until the lithium-ion battery negative electrode coating substrate is dried, wherein the first steam rate is greater than the second steam rate, the first wind speed range is less than the second wind speed range, and the first temperature range is less than the second temperature range.

[0008] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0009] First, a steam regulating component is installed in the drying equipment. Then, a lithium-ion battery anode coating substrate is obtained and fed into the drying equipment for the first drying stage. The steam regulating component controls the steam solvent at a first steam rate to steam-treat the lithium-ion battery anode coating substrate, while the airflow regulating component and temperature regulating component of the drying equipment are set within a first airflow range and a first temperature range, respectively. Finally, the real-time temperature of the lithium-ion battery anode coating substrate is detected. If the temperature rise rate gradient difference is less than a preset threshold, the second drying stage begins. The steam regulating component controls the steam solvent at a second steam rate to steam-treat the lithium-ion battery anode coating substrate, while the airflow regulating component and temperature regulating component of the drying equipment are set within a second airflow range and a second temperature range, until the lithium-ion battery anode coating substrate is dried completely. Herein, the first steam rate is greater than the second steam rate, the first airflow range is less than the second airflow range, and the first temperature range is less than the second temperature range. This method solves the technical problem of poor drying effect of lithium-ion battery anode coatings in existing technologies, achieving dynamic optimization control of the drying process through staged adjustment of steam rate, airflow, and temperature, thereby improving the drying effect. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic flowchart of a lithium battery negative electrode coating and drying process control method provided in an embodiment of this application.

[0012] Figure 2 This is a schematic diagram of the control system for the coating and drying process of lithium-ion battery anode provided in an embodiment of this application.

[0013] Explanation of reference numerals in the attached drawings: Component setting module 11, first drying module 12, second drying module 13. Detailed Implementation

[0014] This application provides a method and system for controlling the coating and drying process of lithium-ion battery anodes, thereby solving the technical problem of poor coating and drying effect of lithium-ion battery anodes in the prior art.

[0015] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0016] It should be noted that the terms "comprising" and "having" are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to these processes, methods, products, or devices.

[0017] Example 1, as Figure 1 As shown, this application provides a method for controlling the coating and drying process of a lithium battery negative electrode, wherein the method includes:

[0018] Install a steam conditioning component in the drying equipment.

[0019] In this embodiment, setting a steam regulation component in the drying equipment refers to integrating a steam supply and regulation system into the air inlet or internal hot air circulation path of the drying equipment. The steam regulation component includes a steam generator, a steam delivery pipeline, a steam solvent storage tank, a steam rate regulating valve, and a distributed injection unit. The steam generator is connected to the steam solvent storage tank and is used to heat the solvent and convert it into steam. The steam delivery pipeline is used to deliver the generated solvent vapor to the drying chamber. The steam rate regulating valve is set on the steam delivery pipeline and is used to adjust the volume fraction and flow rate of the solvent vapor entering the drying equipment in real time according to control commands, thereby outputting different steam rates in the first drying stage and the second drying stage. The distributed injection unit is arranged in multiple positions in the drying chamber to uniformly disperse the steam flow and form a stable steam atmosphere, ensuring that the lithium battery negative electrode coating substrate can fully contact an appropriate amount of steam environment in the early stage of drying, reducing the evaporation gradient on the coating surface, and avoiding problems such as excessively rapid skinning on the film surface or internal solvent retention.

[0020] Furthermore, the steam conditioning assembly includes a steam generator, a steam delivery pipeline, a steam solvent, and a steam rate regulating valve; the steam rate regulating valve is used to control the volume fraction of solvent vapor entering the drying equipment to regulate the values ​​of the first steam rate and the second steam rate.

[0021] Furthermore, the vapor solvent is N-methylpyrrolidone or deionized water.

[0022] A steam generator is used to heat the steam solvent and convert it into high-temperature steam. The steam solvent can be N-methylpyrrolidone (NMP) or deionized water. The steam delivery pipeline introduces the generated steam into the working chamber of the drying equipment and connects to multiple dispersed outlets to ensure that the steam is evenly distributed inside the drying chamber. A steam rate regulating valve is set on the steam delivery pipeline to adjust the steam supply intensity entering the drying equipment by changing the steam flow rate and volume fraction, thereby corresponding to the process requirements of the first steam rate and the second steam rate. The first steam rate is higher than the second steam rate to create a higher steam concentration environment in the early stage of drying, reducing the risk of surface skinning caused by the rapid evaporation of solvent on the surface of the coated substrate. In the subsequent stage, the steam rate is reduced and the wind speed and temperature are increased to achieve efficient removal of residual solvent from the coated substrate.

[0023] A lithium-ion battery anode coating substrate is obtained, and the lithium-ion battery anode coating substrate is sent into the drying equipment to perform a first drying stage. The steam regulating component is used to control the steam solvent to steam treat the lithium-ion battery anode coating substrate at a first steam rate, while the wind speed regulating component and temperature regulating component of the drying equipment are set to a first wind speed range and a first temperature range, respectively.

[0024] In this embodiment, obtaining the lithium-ion battery anode coating substrate refers to using a uniformly coated anode current collector (e.g., copper foil) as the drying object, and continuously or intermittently feeding it into the drying chamber of a drying equipment via a conveying device. Upon entering the drying chamber, a first drying stage is performed. In this stage, the steam regulating component outputs solvent vapor at a preset first steam rate, which is uniformly applied to the lithium-ion battery anode coating substrate through spray pipes arranged within the drying chamber, subjecting it to steam treatment in a steam atmosphere. This reduces the difference in solvent evaporation rates between the coating surface and the interior, preventing excessively rapid surface crusting. Simultaneously, the airflow regulating component of the drying equipment controls the circulating airflow within the chamber to a first airflow rate range, ensuring uniform distribution of solvent vapor and carrier gas on the coating surface without strong disturbances. The temperature regulating component maintains the chamber environment within a first temperature range, keeping the coating in a gently warming state.

[0025] Furthermore, the method of feeding the lithium battery negative electrode coated substrate into the drying equipment to perform a first drying stage includes:

[0026] The wet film thickness and coating solvent type of the lithium-ion battery anode coating substrate, as well as the vapor solvent type of the vapor control component, are collected. A heat transfer-mass transfer coupling model is constructed based on the coating solvent type and the vapor solvent type, wherein the heat transfer-mass transfer coupling model is obtained by coupling a first heat transfer mapping model and a first mass transfer mapping model. The wet film thickness is analyzed using the heat transfer-mass transfer coupling model to obtain a first vapor rate for matching the lithium-ion battery anode coating substrate.

[0027] Before the lithium-ion battery anode coating substrate is sent to the drying equipment for the first drying stage, key parameters of the lithium-ion battery anode coating substrate are collected. These key parameters include the wet film thickness, the type of solvent used in the coating slurry, and the type of steam solvent used in the steam conditioning component. A heat-mass transfer coupling model is constructed based on the coating solvent type and the steam solvent type to predict and optimize the drying behavior of the wet film under steam treatment conditions. This heat-mass transfer coupling model is obtained by coupling a first heat transfer mapping model and a first mass transfer mapping model through parameter alignment and range intersection. The first heat transfer mapping model is established through finite element calculations and mapping relationships with experimental data to analyze the temperature distribution characteristics under different wet film thicknesses and steam rates, thereby preventing thermal damage to the coating surface due to excessively rapid heating. The first mass transfer mapping model is used to analyze the diffusion flux of solvent molecules and the change law of steam concentration in the wet film thickness direction, thereby ensuring that the internal solvent can migrate smoothly to the surface and be discharged, avoiding internal residue.

[0028] By inputting the wet film thickness parameter into the heat transfer-mass transfer coupling model for calculation and analysis, a first steam rate matching the current coating conditions can be obtained. This steam rate serves as the execution control parameter of the steam regulation component in the first drying stage, enabling the lithium battery anode coating substrate to form a dynamic balance between surface and internal solvent migration in the early stage of drying, thereby improving the overall drying uniformity and stability.

[0029] Furthermore, the methods for constructing the first heat transfer mapping model include:

[0030] A heat transfer test sample group is set up, which includes coating wet film thickness samples and steam rate samples set under the steam solvent type and the coating solvent type. A heat transfer model of the lithium battery negative electrode coating substrate is established using a finite element system. The heat transfer test data of the lithium battery negative electrode coating substrate based on the heat transfer test sample group is obtained by simulation according to the heat transfer model. The heat transfer test data includes thermal damage data and temperature distribution data of the lithium battery negative electrode coating substrate. An optimal heat transfer-steam rate range for different coating wet film thicknesses is set using the heat transfer test data. A first heat transfer mapping model is obtained based on the mapping relationship between different coating wet film thicknesses and the corresponding optimal heat transfer-steam rate ranges.

[0031] First, a heat transfer test sample group was set up, consisting of samples of wet film thickness and corresponding steam rates under different combinations of vapor solvent and coating solvent types. Then, a heat transfer model of the lithium-ion battery anode coating substrate was established using a finite element method (FEM). This model incorporated the heat exchange characteristics of the vapor atmosphere and the thermophysical parameters of the wet film material into the boundary conditions, and simulated the influence of steam rate and film thickness variations on heat flux distribution over time. Simulation calculations were performed based on the heat transfer model to obtain heat transfer test data of the lithium-ion battery anode coating substrate under the conditions of the heat transfer test sample group. This data included temperature distribution curves of the coating layer at different locations and thermal damage characteristic data caused by excessively high temperatures. Then, based on the simulation output, an optimal heat transfer-steam rate range was extracted for different wet film thicknesses, i.e., a range within which surface thermal damage could be avoided while ensuring a uniform temperature gradient distribution. Finally, a first heat transfer mapping model was formed by establishing a mapping relationship between different wet film thicknesses and their corresponding optimal heat transfer-steam rate ranges.

[0032] Furthermore, the methods for constructing the first mass transfer mapping model include:

[0033] A mass transfer test sample group is set up, which includes coating wet film thickness samples and vapor rate samples set under the vapor solvent type and the coating solvent type. A mass transfer model of the lithium battery negative electrode coating substrate is established using a finite element system. Mass transfer test data of the lithium battery negative electrode coating substrate based on the mass transfer test sample group is obtained by simulation according to the mass transfer model. The mass transfer test data includes the vapor concentration change and solvent diffusion flux of the lithium battery negative electrode coating substrate. An optimal mass transfer-vapor rate range for different coating wet film thicknesses is set using the mass transfer test data. A first mass transfer mapping model is obtained based on the mapping relationship between different coating wet film thicknesses and the corresponding optimal mass transfer-vapor rate ranges.

[0034] First, a mass transfer test sample group was set up, consisting of coating wet film thickness samples and vapor rate samples under different combinations of vapor solvent and coating solvent types. This group was used to cover the experimental and simulation basis data of solvent evaporation and diffusion characteristics of the coating layer under different operating conditions. Then, a mass transfer model of the lithium-ion battery anode coating substrate was established using a finite element method. This model employs a modeling method combining porous media diffusion theory and boundary layer transport mechanism, considering both the solvent molecule diffusion behavior inside the coating wet film and the vapor atmosphere concentration gradient, and introducing solvent partial pressure changes under different vapor rates in the boundary conditions. Simulation calculations were performed based on the mass transfer model to obtain mass transfer test data of the lithium-ion battery anode coating substrate under the conditions of the mass transfer test sample group. The mass transfer test data includes vapor concentration change curves inside and on the surface of the coating layer, as well as the solvent diffusion flux distribution over time. Then, using the simulation output, the optimal mass transfer-vapor rate range is extracted for different wet film thicknesses. Within this range, uniform migration and smooth evaporation of the internal solvent can be achieved, while avoiding residue due to excessively low vapor rates or surface hindrance effects due to excessively high vapor rates. Finally, by establishing a mapping relationship between different wet film thicknesses and their corresponding optimal mass transfer-vapor rate ranges, the first mass transfer mapping model is obtained.

[0035] Furthermore, the heat transfer-mass transfer coupling model is obtained by coupling the first heat transfer mapping model and the first mass transfer mapping model, the method of which includes:

[0036] Align the preferred heat transfer-steam rate range and preferred mass transfer-steam rate range of the first heat transfer mapping model and the first mass transfer mapping model to obtain the intersection steam rate range for different coating wet film thicknesses; establish a damage objective function, and call the damage objective function to perform optimization in the intersection steam rate range to obtain the first steam rate.

[0037] Specifically, the optimal heat transfer-vapor rate range obtained from the first heat transfer mapping model for different wet film thicknesses is aligned and compared with the optimal mass transfer-vapor rate range obtained from the first mass transfer mapping model for the same wet film thickness. By taking the intersection of the two ranges, the overlapping vapor rate range corresponding to different wet film thicknesses is obtained, taking into account both surface thermal damage suppression and unimpeded internal solvent diffusion. A damage objective function is established within the overlapping vapor rate range, with the optimization objectives being minimizing the thermal damage risk of the coating layer and minimizing the residual solvent concentration. Weighting coefficients can be introduced to balance temperature distribution uniformity and solvent diffusion efficiency. By calling the optimization algorithm to optimize the damage objective function within the overlapping vapor rate range, a first vapor rate matching the wet film thickness of the lithium battery anode coating substrate is finally obtained. This vapor rate is used as the steam supply parameter for the first drying stage and input to the steam regulation component to achieve optimal drying control under the dual constraints of heat transfer and mass transfer.

[0038] The damage objective function can be represented in a weighted form as follows: F(v) = αD(v,h) + βC(v,h) + γG(v,h), where v represents the vapor rate, constrained within the vapor rate range of the heat transfer-mass transfer intersection; h represents the wet film thickness; D(v,h) represents the thermal damage index that may occur on the surface of the coating layer under vapor rate v and film thickness h, derived from the temperature distribution and thermal stress data of the first heat transfer mapping model; C(v,h) represents the normalized index of residual solvent concentration under vapor rate v and film thickness h, derived from the solvent diffusion flux and concentration field data of the first mass transfer mapping model; G(v,h) represents the temperature distribution uniformity index, used to measure the gentleness of the temperature gradient within the coating layer; α, β, and γ are weighting coefficients, reflecting the importance attached to thermal damage risk, residual solvent, and temperature distribution uniformity, respectively, and satisfying that their summation is 1.

[0039] The first steam rate is obtained by optimizing the function F(v) using an optimization algorithm (such as genetic algorithm, particle swarm optimization, or gradient descent) to achieve the minimum steam rate within the range of overlapping steam rates.

[0040] To find the optimal solution for the damage objective function F(v), a genetic algorithm can be used. Specifically, this involves: initializing the population within the heat transfer-mass transfer intersection steam rate range, randomly generating multiple candidate steam rate individuals, and using these candidates as the initial population; calculating the fitness of each candidate individual based on the damage objective function, where the fitness value is inversely proportional to the damage objective function value (the smaller the damage objective function value, the higher the fitness value); then, using a selection operator to screen the population individuals according to the fitness distribution, selecting superior individuals to enter the mating pool; performing a crossover operation in the mating pool, exchanging and combining the parameters of individuals within two candidate steam rate ranges to generate new candidate steam rate individuals; simultaneously, a mutation operation randomly perturbs individual steam rate individuals to ensure the search process has global exploration capabilities and avoids getting trapped in local optima. Subsequently, a new generation of population is formed, and the fitness is recalculated, repeating the selection, crossover, and mutation operations. Finally, when the number of iterations reaches the preset upper limit, or when the improvement in fitness of the population is less than the preset threshold for several consecutive generations, the algorithm is determined to have converged, and the steam rate corresponding to the individual with the highest fitness in the final population is taken as the first steam rate.

[0041] The real-time temperature of the lithium-ion battery anode coating substrate is detected. If the temperature rise rate gradient difference of the real-time temperature is less than a preset threshold, the second drying stage is entered. The steam regulating component is used to control the steam solvent at a second steam rate to steam treat the lithium-ion battery anode coating substrate. At the same time, the wind speed regulating component and temperature regulating component of the drying equipment are set to a second wind speed range and a second temperature range until the lithium-ion battery anode coating substrate is dried. Wherein, the first steam rate is greater than the second steam rate, the first wind speed range is less than the second wind speed range, and the first temperature range is less than the second temperature range.

[0042] In this embodiment, the temperature of the lithium-ion battery negative electrode coating substrate within the drying equipment is monitored in real time. The real-time temperature is collected by an array of temperature sensors or an infrared thermometer arranged on the surface and interior of the substrate, and the temperature rise rate and its gradient are calculated using a time series analysis. When the detection results show that the gradient difference in the temperature rise rate is less than a preset threshold, it indicates that the heat transfer process between the surface and interior of the coating substrate is approaching equilibrium, and the drying process transitions from the initial solvent evaporation stage to the solvent residue removal stage. At this point, the drying process is switched to the second drying stage.

[0043] In the second drying stage, the steam regulating component supplies steam solvent at a preset second steam rate, which is lower than the first steam rate in the first drying stage, to avoid excessive steam inhibiting the discharge of residual solvent. Simultaneously, the wind speed regulating component increases the circulating wind speed within the drying chamber to a second wind speed range to enhance the renewal of the chamber atmosphere and the driving force for solvent diffusion; the temperature regulating component raises the ambient temperature to a second temperature range to accelerate the evaporation and migration of residual solvent in the coated substrate. Through the coordinated control of the reduced steam rate and the increased wind speed and temperature, the coated substrate can achieve thorough drying while ensuring the integrity of the coating structure.

[0044] Furthermore, the method for controlling the vapor solvent to perform vapor treatment on the lithium battery negative electrode coating substrate using the vapor conditioning component at a second vapor rate, and obtaining the second vapor rate, includes:

[0045] Based on the remaining wet film thickness of the lithium-ion battery anode coating substrate, the heat transfer-mass transfer coupling model analyzes the remaining wet film thickness with the first vapor rate as a constraint to obtain a second vapor rate for matching the lithium-ion battery anode coating substrate.

[0046] Specifically, the state of the lithium-ion battery anode coating substrate entering the second drying stage is monitored, and the remaining wet film thickness parameter is extracted. This thickness can be obtained in real time through online optical thickness sensors, laser interferometry, or infrared absorption spectroscopy analysis. The remaining wet film thickness is input into the heat transfer-mass transfer coupling model, and the residual solvent diffusion efficiency and thermal damage risk under different steam rates are calculated and analyzed, with the first steam rate as a constraint condition, that is, ensuring that the continuity of the temperature distribution and diffusion boundary established by the steam supply conditions in the first stage is not destroyed. Based on the model output results, the optimal steam rate range that can simultaneously satisfy the conditions of no thermal damage to the surface and sufficient internal solvent migration under the current remaining wet film thickness is selected, and optimization is performed within this range to obtain the optimal second steam rate.

[0047] Furthermore, the heat-mass transfer coupling model is connected to an adaptive drying regulation model. The adaptive drying regulation model is trained to obtain steam rate, wind speed parameters, and temperature parameters to achieve the drying target. Based on the first drying stage, the adaptive drying regulation model adaptively outputs a first regulation parameter and a first temperature parameter in the first wind speed range and a first temperature range according to the first steam rate. Based on the second drying stage, the adaptive drying regulation model adaptively outputs a second regulation parameter and a second temperature parameter in the second wind speed range and a second temperature range according to the second steam rate.

[0048] A heat-mass transfer coupling model is established in conjunction with an adaptive drying control model. The adaptive drying control model is trained with the drying target as the optimization objective. This objective may include residual solvent concentration below a preset threshold, uniform temperature distribution of the coating layer, and no thermal damage to the coating surface. During training, different steam rates, wind speed parameters, and temperature parameters are used as input variables, and the drying completion degree and structural integrity of the coating substrate are used as output feedback. The model is continuously iteratively optimized through machine learning algorithms (such as neural networks, reinforcement learning, or support vector regression) to form a model that can adaptively predict the optimal control parameters.

[0049] Based on the first drying stage, the adaptive drying adjustment model calls upon the constraints provided by the heat transfer-mass transfer coupling model, takes the first steam rate as the core input, and performs adjustment optimization within the first wind speed range and the first temperature range, outputting the matched first adjustment parameter and the first temperature parameter as real-time control commands for the drying equipment. After entering the second drying stage, the adaptive drying adjustment model performs the same adaptive calculation based on the second steam rate, the second wind speed range, and the second temperature range, outputting the second adjustment parameter and the second temperature parameter. This enables the drying equipment to achieve adaptive matching and dynamic control of parameters in different stages, ensuring the uniformity and stability of the coating substrate drying.

[0050] The training process of the adaptive drying adjustment model includes: First, constructing an input feature set, which includes process variables such as coating wet film thickness, coating solvent type, steam solvent type, steam rate, wind speed parameter, and temperature parameter; simultaneously collecting an output target set, which includes drying achievement indicators of the coated substrate (such as residual solvent concentration), thermal damage indicators (such as surface crack or discoloration detection results), and temperature distribution uniformity indicators (such as the root mean square error of temperature gradient). Second, defining a training objective function, with the optimization direction being maximizing drying achievement, minimizing thermal damage risk, and optimizing temperature distribution uniformity, can be expressed as a weighted comprehensive objective function: L = λ1C + λ2D + λ3G, where C is the normalized residual solvent concentration indicator, D is the thermal damage risk indicator, G is the temperature distribution uniformity indicator, and λ1, λ2, and λ3 are adjustable weight coefficients that sum to 1.

[0051] During training, historical experimental data and data samples generated by the heat-mass transfer coupling model are used as the training set. Machine learning methods are employed for modeling and optimization. For example, deep neural networks (DNNs) are used to model the nonlinear relationship between input features and output indicators, or reinforcement learning (RL) frameworks are used to continuously try different combinations of steam rate, wind speed, and temperature in a simulated environment, converging to the optimal strategy through reward function feedback. During training iterations, the model is considered complete when the objective function value on the validation set decreases below a preset threshold for several consecutive rounds, or when the overall error converges to the target accuracy.

[0052] In summary, the embodiments of this application have at least the following technical effects:

[0053] First, a steam regulating component is installed in the drying equipment. Then, a lithium-ion battery anode coating substrate is obtained and fed into the drying equipment for the first drying stage. The steam regulating component controls the steam solvent at a first steam rate to steam-treat the lithium-ion battery anode coating substrate, while the airflow regulating component and temperature regulating component of the drying equipment are set within a first airflow range and a first temperature range, respectively. Finally, the real-time temperature of the lithium-ion battery anode coating substrate is detected. If the temperature rise rate gradient difference is less than a preset threshold, the second drying stage begins. The steam regulating component controls the steam solvent at a second steam rate to steam-treat the lithium-ion battery anode coating substrate, while the airflow regulating component and temperature regulating component of the drying equipment are set within a second airflow range and a second temperature range, until the lithium-ion battery anode coating substrate is dried completely. Herein, the first steam rate is greater than the second steam rate, the first airflow range is less than the second airflow range, and the first temperature range is less than the second temperature range. This method solves the technical problem of poor drying effect of lithium-ion battery anode coatings in existing technologies, achieving dynamic optimization control of the drying process through staged adjustment of steam rate, airflow, and temperature, thereby improving the drying effect.

[0054] Example 2, based on the same inventive concept as the lithium battery negative electrode coating and drying process control method in the foregoing examples, such as... Figure 2 As shown, this application provides a control system for the coating and drying process of lithium-ion battery anodes, wherein the system includes:

[0055] Component setting module 11: Sets a steam regulating component in the drying equipment; First drying module 12: Obtains the lithium battery negative electrode coating substrate, sends the lithium battery negative electrode coating substrate into the drying equipment to perform a first drying stage, uses the steam regulating component to control the steam solvent at a first steam rate to steam treat the lithium battery negative electrode coating substrate, and simultaneously keeps the wind speed regulating component and temperature regulating component of the drying equipment in a first wind speed range and a first temperature range; Second drying module 13: Detects the real-time temperature of the lithium battery negative electrode coating substrate, if the temperature rise rate gradient difference of the real-time temperature is less than a preset threshold, enters the second drying stage, uses the steam regulating component to control the steam solvent at a second steam rate to steam treat the lithium battery negative electrode coating substrate, and simultaneously keeps the wind speed regulating component and temperature regulating component of the drying equipment in a second wind speed range and a second temperature range, until the lithium battery negative electrode coating substrate is dried, wherein the first steam rate is greater than the second steam rate, the first wind speed range is less than the second wind speed range, and the first temperature range is less than the second temperature range.

[0056] Furthermore, the component setting module 11 is used to perform the following method:

[0057] The steam regulation assembly includes a steam generator, a steam delivery pipeline, a steam solvent, and a steam rate regulating valve; the steam rate regulating valve is used to control the volume fraction of solvent vapor entering the drying equipment to regulate the values ​​of the first steam rate and the second steam rate.

[0058] Furthermore, the first drying module 12 is used to perform the following method:

[0059] The wet film thickness and coating solvent type of the lithium-ion battery anode coating substrate, as well as the vapor solvent type of the vapor control component, are collected. A heat transfer-mass transfer coupling model is constructed based on the coating solvent type and the vapor solvent type, wherein the heat transfer-mass transfer coupling model is obtained by coupling a first heat transfer mapping model and a first mass transfer mapping model. The wet film thickness is analyzed using the heat transfer-mass transfer coupling model to obtain a first vapor rate for matching the lithium-ion battery anode coating substrate.

[0060] Furthermore, the first drying module 12 is used to perform the following method:

[0061] A heat transfer test sample group is set up, which includes coating wet film thickness samples and steam rate samples set under the steam solvent type and the coating solvent type. A heat transfer model of the lithium battery negative electrode coating substrate is established using a finite element system. The heat transfer test data of the lithium battery negative electrode coating substrate based on the heat transfer test sample group is obtained by simulation according to the heat transfer model. The heat transfer test data includes thermal damage data and temperature distribution data of the lithium battery negative electrode coating substrate. An optimal heat transfer-steam rate range for different coating wet film thicknesses is set using the heat transfer test data. A first heat transfer mapping model is obtained based on the mapping relationship between different coating wet film thicknesses and the corresponding optimal heat transfer-steam rate ranges.

[0062] Furthermore, the first drying module 12 is used to perform the following method:

[0063] A mass transfer test sample group is set up, which includes coating wet film thickness samples and vapor rate samples set under the vapor solvent type and the coating solvent type. A mass transfer model of the lithium battery negative electrode coating substrate is established using a finite element system. Mass transfer test data of the lithium battery negative electrode coating substrate based on the mass transfer test sample group is obtained by simulation according to the mass transfer model. The mass transfer test data includes the vapor concentration change and solvent diffusion flux of the lithium battery negative electrode coating substrate. An optimal mass transfer-vapor rate range for different coating wet film thicknesses is set using the mass transfer test data. A first mass transfer mapping model is obtained based on the mapping relationship between different coating wet film thicknesses and the corresponding optimal mass transfer-vapor rate ranges.

[0064] Furthermore, the first drying module 12 is used to perform the following method:

[0065] Align the preferred heat transfer-steam rate range and preferred mass transfer-steam rate range of the first heat transfer mapping model and the first mass transfer mapping model to obtain the intersection steam rate range for different coating wet film thicknesses; establish a damage objective function, and call the damage objective function to perform optimization in the intersection steam rate range to obtain the first steam rate.

[0066] Furthermore, the second drying module 13 is used to perform the following method:

[0067] Based on the remaining wet film thickness of the lithium-ion battery anode coating substrate, the heat transfer-mass transfer coupling model analyzes the remaining wet film thickness with the first vapor rate as a constraint to obtain a second vapor rate for matching the lithium-ion battery anode coating substrate.

[0068] Furthermore, the second drying module 13 is used to perform the following method:

[0069] The heat-mass transfer coupling model is connected to the adaptive drying regulation model. The adaptive drying regulation model is trained to obtain steam rate, wind speed parameters, and temperature parameters to achieve the drying target. Based on the first drying stage, the adaptive drying regulation model adaptively outputs a first regulation parameter and a first temperature parameter in the first wind speed range and a first temperature range according to the first steam rate. Based on the second drying stage, the adaptive drying regulation model adaptively outputs a second regulation parameter and a second temperature parameter in the second wind speed range and a second temperature range according to the second steam rate.

[0070] Furthermore, the first drying module 12 is used to perform the following method:

[0071] The vapor solvent is N-methylpyrrolidone or deionized water.

[0072] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0073] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0074] This specification and accompanying drawings are merely illustrative examples of this application and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Therefore, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A method for controlling the coating and drying process of a lithium battery negative electrode, characterized in that, The method includes: Install a steam conditioning component in the drying equipment; A lithium battery anode coating substrate is obtained, and the lithium battery anode coating substrate is sent into the drying equipment to perform a first drying stage. The steam regulating component is used to control the steam solvent to steam treat the lithium battery anode coating substrate at a first steam rate, while the wind speed regulating component and temperature regulating component of the drying equipment are set to a first wind speed range and a first temperature range. The real-time temperature of the lithium battery anode coating substrate is detected. If the temperature rise rate gradient difference of the real-time temperature is less than a preset threshold, the second drying stage is entered. The steam regulating component is used to control the steam solvent to steam treat the lithium battery anode coating substrate at a second steam rate. At the same time, the wind speed regulating component and temperature regulating component of the drying equipment are set to the second wind speed range and the second temperature range until the lithium battery anode coating substrate is dried. Wherein, the first steam rate is greater than the second steam rate, the first wind speed range is less than the second wind speed range, and the first temperature range is less than the second temperature range; The method of feeding the lithium battery negative electrode coated substrate into the drying equipment to perform the first drying stage includes: The wet film thickness and coating solvent type of the lithium battery negative electrode coating substrate, as well as the steam solvent type of the steam conditioning component, are collected. A heat transfer-mass transfer coupling model is constructed based on the type of coating solvent and the type of vapor solvent, wherein the heat transfer-mass transfer coupling model is obtained by coupling the first heat transfer mapping model and the first mass transfer mapping model. The thickness of the wet coating is analyzed using the heat transfer-mass transfer coupling model to obtain the first vapor rate for matching the lithium battery anode coating substrate.

2. The method as described in claim 1, characterized in that, The steam conditioning assembly includes a steam generator, a steam delivery pipeline, a steam solvent, and a steam rate regulating valve; The steam rate regulating valve is used to control the volume fraction of solvent vapor entering the drying equipment to adjust the values ​​of the first steam rate and the second steam rate.

3. The method as described in claim 1, characterized in that, The methods for constructing the first heat transfer mapping model include: A heat transfer test sample group is set up, which includes a wet film thickness sample and a vapor rate sample set under the steam solvent type and the coating solvent type. A heat transfer model of the lithium battery anode coating substrate is established using a finite element system. Based on the heat transfer model, heat transfer test data of the lithium battery anode coating substrate based on the heat transfer test sample group is obtained through simulation. The heat transfer test data includes thermal damage data and temperature distribution data of the lithium battery anode coating substrate. The heat transfer-steam rate range for different wet film thicknesses was set using the heat transfer test data. Based on the mapping relationship between different wet film thicknesses and corresponding heat transfer-steam rate ranges, the first heat transfer mapping model is obtained.

4. The method as described in claim 1, characterized in that, The methods for constructing the first mass transfer mapping model include: A mass transfer test sample group is set up, which includes a wet film thickness sample and a vapor rate sample set under the vapor solvent type and the coating solvent type. A mass transfer model of the lithium-ion battery anode coating substrate is established using a finite element system. Mass transfer test data of the lithium-ion battery anode coating substrate based on the mass transfer test sample group is obtained by simulation using the mass transfer model. The mass transfer test data includes the vapor concentration change and solvent diffusion flux of the lithium-ion battery anode coating substrate. The mass transfer-vapor rate range for different wet film thicknesses was set using the mass transfer test data. Based on the mapping relationship between different wet film thicknesses and corresponding mass transfer-vapor rate ranges, the first mass transfer mapping model is obtained.

5. The method as described in claim 1, characterized in that, The heat transfer-mass transfer coupling model is obtained by coupling the first heat transfer mapping model and the first mass transfer mapping model, and the method includes: Align the heat transfer-steam rate range and mass transfer-steam rate range of the first heat transfer mapping model and the first mass transfer mapping model to obtain the intersection steam rate range for different wet film thicknesses. A damage objective function is established, and the damage objective function is called to perform optimization within the intersection steam rate range to obtain the first steam rate.

6. The method as described in claim 1, characterized in that, The method for obtaining the second steam rate by using the steam conditioning component to control the steam solvent to perform steam treatment on the lithium battery negative electrode coating substrate at a second steam rate includes: Based on the remaining wet film thickness of the lithium battery negative electrode coating substrate; The heat transfer-mass transfer coupling model analyzes the remaining wet film thickness with the first vapor rate as a constraint to obtain a second vapor rate for matching the lithium battery anode coating substrate.

7. The method as described in claim 1, characterized in that, The heat transfer-mass transfer coupling model is connected to the adaptive drying regulation model, which is trained on steam rate, wind speed parameters and temperature parameters to achieve the drying target. Based on the first drying stage, the adaptive drying adjustment model adaptively outputs a first adjustment parameter and a first temperature parameter within the first wind speed range and the first temperature range according to the first steam rate. Based on the second drying stage, the adaptive drying adjustment model adaptively outputs a second adjustment parameter and a second temperature parameter within the second wind speed range and the second temperature range according to the second steam rate.

8. The method as described in claim 1, characterized in that, The vapor solvent is N-methylpyrrolidone or deionized water.

9. A control system for the coating and drying process of lithium battery negative electrode, characterized in that, The system is used to implement the lithium battery anode coating and drying process control method according to any one of claims 1-8, the system comprising: Component setting module: Sets the steam conditioning components in the drying equipment; First drying module: Obtain lithium battery negative electrode coated substrate, send the lithium battery negative electrode coated substrate into the drying equipment to perform the first drying stage, use the steam regulating component to control the steam solvent to steam treat the lithium battery negative electrode coated substrate at a first steam rate, and at the same time keep the wind speed regulating component and temperature regulating component of the drying equipment in a first wind speed range and a first temperature range. The second drying module detects the real-time temperature of the lithium-ion battery negative electrode coating substrate. If the temperature rise rate gradient difference of the real-time temperature is less than a preset threshold, it enters the second drying stage. The steam regulating component controls the steam solvent to perform steam treatment on the lithium-ion battery negative electrode coating substrate at a second steam rate. At the same time, the wind speed regulating component and temperature regulating component of the drying equipment are set to a second wind speed range and a second temperature range until the lithium-ion battery negative electrode coating substrate is dried. The first steam rate is greater than the second steam rate, the first wind speed range is less than the second wind speed range, and the first temperature range is less than the second temperature range.

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