Transverse flux radio frequency induction heating battery tab blank area wrinkle removal system and method

Abstract

The present application relates to battery processing and manufacturing technology field, provide a kind of transverse magnetic flux radio frequency induction heating battery pole piece blank area wrinkle removal method, megahertz level radio frequency signal is output by radio frequency power supply, after impedance matching, lossless feed into transverse magnetic flux inductor, generate transverse magnetic force line to make eddy current closed in battery pole piece plane. Again with active water-cooling magnetic flux shield plate generates reverse magnetic field shielding magnetic flux, and through built-in water-cooling channel and timely heat dissipation. While by supporting support roller keeps inductor and pole piece gap constant, cooperate temperature sensor closed loop temperature control and heat to softening state, by production line winding mechanism drive plastic extension of softening zone, finally through frozen roll quenching, overall complete battery pole piece complete heat treatment process. The present application also provides a kind of device, the method and device realize ultra-thin battery pole piece effective induction heating and online annealing. Both can efficiently eliminate pole piece processing residual stress, smooth wrinkle defect, and whole process without damaging coating structure, no powder crack problem.

Description

Technical Field

[0001] This invention relates to the field of battery processing and manufacturing technology, and in particular to a system and method for removing wrinkles in the blank area of ​​a battery electrode using transverse magnetic flux radio frequency induction heating. Background Technology

[0002] High-energy-density lithium-ion batteries and emerging solid-state batteries are core components in new energy vehicles, energy storage systems, and other fields. Their performance improvement and large-scale manufacturing capabilities have become key competitive advantages in the industry. Roll-to-roll manufacturing equipment, as the core carrier for achieving efficient and continuous mass production of batteries, directly determines the quality stability and production cost control capabilities of battery products through its technological advancement. Among these processes, the electrode coating process is a core step in battery electrode preparation. Its main function is to compact the active material of the electrode, improve the electrode density and energy density, optimize the bonding performance between the active material and the current collector, and lay the foundation for the stability of subsequent charge-discharge cycles of the battery.

[0003] During the electrode rolling process, the metal current collector itself has a certain degree of ductility. Furthermore, the uneven stress and inconsistent stretching between the coated and uncoated areas during rolling easily lead to residual stress in the uncoated areas, resulting in appearance defects and structural problems such as wavy wrinkles. Specifically, during rolling, the coated area stretches under pressure, while the uncoated area, lacking support from the active material, hardly stretches. This uneven stretching causes internal stress accumulation in the uncoated area, leading to wavy undulations and, in severe cases, fine wrinkles. This problem is more pronounced in thin current collectors below 12µm and is one of the key bottlenecks hindering the large-scale application of thin current collectors.

[0004] Various annealing processes are employed to relieve stress and smooth the rolled electrodes. Traditional annealing methods mainly include in-furnace annealing and hot air annealing, which are contact or semi-contact processes. However, these processes have significant technical drawbacks: Firstly, contact annealing easily leads to scratches and contamination on the electrode surface, damaging its integrity and further affecting battery performance. Secondly, traditional annealing processes suffer from poor heating uniformity, making it difficult to accurately position and anneal the blank areas of the electrode. This results in low annealing efficiency, making it unsuitable for the high-speed continuous production cycle requirements of roll-to-roll manufacturing. Furthermore, high energy consumption hinders production cost control and fails to meet the demands of large-scale, high-precision manufacturing of high-energy-density lithium-ion batteries and solid-state batteries. Summary of the Invention

[0005] Long-term practice has shown that in the lithium-ion battery electrode rolling process, the extremely high normal linear load applied to increase the compaction density of the active material causes the coating area of ​​the active material to produce a significant plastic extension of 1%-5% in the machine running direction. Meanwhile, the blank area for the pre-reserved tab processing does not have obvious plastic deformation due to the lack of coating mediation. This macroscopic elastic-plastic strain mismatch causes huge longitudinal tensile stress and transverse shear stress in the blank area, which in turn forms wavy longitudinal wrinkles with a amplitude of hundreds of micrometers, leading to hidden dangers such as cutting strips, winding misalignment, separator puncture, cell micro-short circuit, and thermal runaway. Existing solutions such as pure mechanical tension intervention, conventional frequency electromagnetic induction heating, laser and infrared heating, and traditional induction wrinkle removal all have insurmountable physical and engineering limitations, including easy damage to electrode coatings, inability to generate effective heating, incidental damage or high cost, difficulty in protecting the heat-sensitive coating, and safety hazards. How to effectively eliminate residual stress and wavy wrinkles in the blank area left after electrode rolling, while adapting to the high-speed continuous production cycle of roll-to-roll, controlling production costs, and without damaging the electrode coating, has become the core technical problem restricting the large-scale and high-precision manufacturing of lithium-ion batteries.

[0006] In view of this, the present invention provides a wrinkle removal system for the blank area of ​​a transverse magnetic flux radio frequency induction heating battery electrode, the transverse magnetic flux radio frequency induction heating battery electrode blank area wrinkle removal system comprising: Step S1: A megahertz-level radio frequency signal is generated by an ultra-high frequency radio frequency power supply. The megahertz-level radio frequency energy is injected into the transverse magnetic flux inductor without reflection after impedance matching. The transverse magnetic flux inductor generates transverse magnetic lines of force that penetrate the plane of the battery electrode, so that eddy currents form a closed loop in the XY plane of the battery electrode, and perform point heating on the blank area of ​​the battery electrode. Step S2: Using an active water-cooled magnetic flux shielding plate, a reverse magnetic field is generated by induced strong eddy currents to shield the magnetic flux, while the heat of the eddy currents can be dissipated through the internal forced water-cooling channel. Step S3: A constant gap is maintained between the transverse magnetic flux sensor and the battery electrode sheet by multiple support rollers; the blank area of ​​the battery electrode sheet is heated to a softened state by temperature sensor feedback control; the softened area is induced to plastically extend by the production line winding mechanism; and the battery electrode sheet is then quenched by a freezing roller to complete the heat treatment process of the battery electrode sheet.

[0007] Preferably, the surface temperature of the freezing roller is 20 to 50 degrees Celsius.

[0008] Preferably, the production line winding mechanism induces 1% to 2% plastic elongation in the softened zone.

[0009] Preferably, closed-loop PID feedback control is performed on the ultra-high frequency radio frequency power supply and the active water-cooled magnetic flux shielding plate based on the temperature data collected by the temperature sensor.

[0010] Preferably, the gap between the transverse flux sensor and the battery electrode is set to 2 to 3 millimeters by adjusting multiple support rollers.

[0011] The present invention also discloses an apparatus for performing the above-described method for removing wrinkles in the blank area of ​​a battery electrode sheet using transverse magnetic flux radio frequency induction heating. The apparatus includes an ultra-high frequency radio frequency power supply, a transverse magnetic flux sensor, and an active water-cooled magnetic flux shielding plate. The ultra-high frequency radio frequency power supply is used to generate megahertz-level radio frequency signals, and injects megahertz-level radio frequency energy into the transverse magnetic flux inductor without reflection after impedance matching. The transverse magnetic flux sensor is used to generate transverse magnetic lines of force that penetrate the plane of the battery electrode, so that eddy currents form a closed loop in the XY plane of the battery electrode, and perform point heating on the blank area of ​​the battery electrode. The active water-cooled magnetic flux shielding plate is fixedly installed on both sides of the transverse magnetic flux sensor perpendicular to the direction of motion. It is used to generate a reverse magnetic field to shield the magnetic flux by inducing strong eddy currents, and at the same time, it can dissipate the heat of the eddy currents through the internal forced water cooling channel. Multiple support rollers are used to maintain a constant gap between the lateral flux sensor and the battery electrode. A temperature sensor is used for feedback control to heat the blank area of ​​the battery electrode to a softened state; Production line winding mechanism, used to induce plastic stretching in the softened zone; A freezing roller is used to quench the battery electrodes.

[0012] Preferably, the transverse flux sensor adopts a coreless structure and is oriented vertically towards the blank area of ​​the battery electrode.

[0013] Preferably, all edges of the active water-cooled magnetic flux shielding plate facing the transverse magnetic flux sensor are chamfered with a radius of R.

[0014] Preferably, the device further includes a control module, the temperature sensor is electrically connected to the control module, and the control module is used to receive the temperature signal transmitted by the temperature sensor and trigger control signals to the ultra-high frequency radio frequency power supply and the active water-cooled magnetic flux shield.

[0015] The present invention also discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the above-described method for wrinkle removal in the blank area of ​​a transverse magnetic flux radio frequency induction heating battery electrode.

[0016] The present invention also discloses a machine-readable storage medium storing instructions for causing a machine to perform the method for removing wrinkles in the blank area of ​​a battery electrode as described in any of the preceding claims.

[0017] This invention provides a method for wrinkle removal in the blank area of ​​battery electrodes using transverse magnetic flux radio frequency induction heating. A megahertz-level radio frequency signal is output from an ultra-high frequency radio frequency power supply and, after impedance matching, is losslessly fed into a transverse magnetic flux inductor. This generates transverse magnetic lines of force, causing eddy currents to close on the battery electrode plane, achieving targeted heating of the blank area. An active water-cooled magnetic flux shielding plate generates a reverse magnetic field to shield the magnetic flux, and a built-in water-cooling channel dissipates heat promptly. Simultaneously, a support roller maintains a constant gap between the inductor and the electrode, and a temperature sensor, combined with closed-loop temperature control, heats the blank area to a softened state. The softened area is then plastically stretched by the production line winding mechanism, and finally quenched by a freezing roller, completing the overall heat treatment process for the battery electrode. This invention also provides an apparatus. This method and apparatus, within the magnetic flux radio frequency induction heating system for wrinkle removal in the blank area of ​​battery electrodes, utilize a coil paired with a streamlined, chamfered, active water-cooled magnetic flux shielding structure. This eliminates the need for expensive magnetic conductors or upgraded microwave frequencies, forming closed eddy currents in the XY plane of the battery electrode, achieving effective induction heating and online annealing of ultra-thin battery electrodes. Simultaneously, through the synergistic effect of streamlined chamfered geometry design and active water-cooled magnetic flux shielding, the tip corona discharge caused by megahertz high-voltage resonance is effectively suppressed within the extremely small process air gap. Precise temperature control avoids the risk of thermal decomposition of PVDF binder at 170℃. It can not only efficiently eliminate residual stress in electrode processing and smooth wrinkle defects, but also does not damage the coating structure or cause powdering and microcracks throughout the process. It takes into account process safety, heating accuracy and mass production applicability, and solves the inherent shortcomings of various processes such as mechanical tension, conventional induction and laser infrared heating. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the lateral magnetic flux sensor and the active water-cooled magnetic flux shielding plate in an apparatus for performing a method for removing wrinkles in the blank area of ​​a battery electrode sheet using lateral magnetic flux radio frequency induction heating, according to one embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the overall structure of an apparatus for performing a method for removing wrinkles in the blank area of ​​a battery electrode sheet using transverse magnetic flux radio frequency induction heating, according to one embodiment of the present invention. Figure 3 This is a cross-sectional schematic diagram of an active water-cooled magnetic flux shielding plate in an apparatus for performing a method for removing wrinkles in the blank area of ​​a battery electrode sheet using transverse magnetic flux radio frequency induction heating, according to one embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures Detailed Implementation

[0021] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0022] In existing battery electrode manufacturing processes, pure mechanical tension intervention relies on traction tension to flatten the electrode. However, due to the electrode substrate being only 6-12 micrometers in size and the coating being highly brittle, this easily leads to micro-cracks in the coating, powdering, and electrode breakage. Furthermore, it cannot eliminate residual micro-lattice stress generated by work hardening. Conventional 20kHz-500kHz mid-to-high frequency electromagnetic induction heating is affected by the skin effect, resulting in a penetration depth much greater than the electrode thickness. After the magnetic lines of force penetrate the foil, the eddy currents on the upper and lower surfaces cancel each other out, making it difficult to generate effective Joule heat. This invention proposes a method for wrinkle removal in the blank area of ​​battery electrodes using transverse magnetic flux radio frequency induction heating, such as... Figure 1-3 As shown, the method for removing wrinkles in the blank area of ​​the transverse magnetic flux radio frequency induction heating battery electrode includes: Step S1: A megahertz-level radio frequency signal is generated by an ultra-high frequency radio frequency power supply. The megahertz-level radio frequency energy is injected into the transverse magnetic flux sensor 1 without reflection after impedance matching. The transverse magnetic flux sensor 1 generates transverse magnetic lines of force that penetrate the plane of the battery electrode 3 vertically, so that the eddy current forms a closed loop in the XY plane of the battery electrode 3, and performs point heating on the blank area of ​​the battery electrode 3. Step S2: Using the active water-cooled magnetic flux shielding plate 2, a reverse magnetic field is generated by induced strong eddy currents to shield the magnetic flux, while the heat of the eddy currents can be dissipated through the internal forced water-cooling channel 8. Step S3: A constant gap is maintained between the transverse magnetic flux sensor 1 and the battery electrode 3 by multiple support rollers 4; the blank area of ​​the battery electrode 3 is heated to a softened state by feedback control through temperature sensor 7; the softened area is induced to plastically extend by production line winding mechanism 5; and the battery electrode 3 is quenched by freezing roller 6 to complete the heat treatment process of the battery electrode 3.

[0023] This invention provides a method for wrinkle removal in the blank area of ​​battery electrodes using transverse magnetic flux radio frequency induction heating. A megahertz-level radio frequency signal is output from an ultra-high frequency radio frequency power supply and, after impedance matching, is losslessly fed into a transverse magnetic flux inductor. This generates transverse magnetic lines of force, causing eddy currents to close in the battery electrode plane, achieving targeted heating of the blank area. An active water-cooled magnetic flux shielding plate generates a reverse magnetic field to shield the magnetic flux, and a built-in water-cooling channel dissipates heat promptly. Simultaneously, a support roller maintains a constant gap between the inductor and the electrode, and a temperature sensor provides closed-loop temperature control to heat the blank area to a softened state. The softened area is then plastically stretched by the production line's winding mechanism, and finally quenched by a freezing roller, completing the entire heat treatment process for the battery electrode. This method, in the magnetic flux radio frequency induction heating system for wrinkle removal in the blank area of ​​battery electrodes, relies on a coil combined with a large-beveled streamlined active water-cooled magnetic flux shielding structure. It eliminates the need for expensive magnetic conductors or upgraded microwave frequencies, forming closed eddy currents in the XY plane of the battery electrode, achieving effective induction heating and online annealing of ultra-thin battery electrodes. Simultaneously, through the synergistic effect of streamlined chamfered geometry design and active water-cooled magnetic flux shielding, the tip corona discharge caused by megahertz high-voltage resonance is effectively suppressed within the extremely small process air gap. Precise temperature control avoids the risk of thermal decomposition of PVDF binder at 170℃. It can not only efficiently eliminate residual stress in electrode processing and smooth wrinkle defects, but also does not damage the coating structure or cause powdering and microcracks throughout the process. It takes into account process safety, heating accuracy and mass production applicability, and solves the inherent shortcomings of various processes such as mechanical tension, conventional induction and laser infrared heating.

[0024] To facilitate rapid and orderly reconstruction of the internal lattice of the softened battery electrode 3, eliminating work hardening and residual stress caused by rolling and slitting, and achieving wrinkle removal and leveling effects, in a more preferred embodiment of this invention, the surface temperature of the freezing roller 6 is 20 to 50 degrees Celsius. Gentle and constant-temperature cooling at 20–50°C is achieved using a closed-loop circulating water / air-cooled constant-temperature unit, with real-time PID adjustment via a precision temperature controller. The freezing roller 6 employs a hollow sandwich flow channel structure, with a constant-temperature circulating medium flowing inside. The roller wall is made of a high thermal conductivity metal material to ensure uniform temperature throughout the circumferential and axial directions of the entire roller. After the battery electrode 3 is softened and plastically stretched by radio frequency induction heating, it is immediately bonded to the surface of the constant-temperature 20–50°C freezing roller 6 and fed at a uniform speed, achieving contact-type uniform and stable cooling with a controllable cooling rate. The front and rear support rollers 4 maintain the battery electrode 3's stable contact with the roller surface, and the production line conveyor speed is matched with the cooling time to ensure a smooth transition of the electrode from a softened state to room-temperature shaping.

[0025] To uniformly release the microscopic residual stress generated during the rolling and slitting processes of the battery electrode 3, smooth out microscopic wrinkles, wavy edges, and warping deformation, and improve the flatness of the electrode, in a more preferred embodiment of the invention, the production line winding mechanism 5 induces a 1% to 2% plastic stretching in the softened zone. The stretching amount is controlled within an extremely low range, not exceeding the tolerance limits of the electrode foil and brittle coating, eliminating the risk of coating micro-cracks, powdering, edge chipping, and electrode breakage, especially suitable for ultra-thin electrode processes with 6-12μm foil. By setting a small linear speed difference between the front and rear traction rollers and the production line winding mechanism, the softened blank area after induction heating of the electrode is smoothly stretched during the material feeding process, precisely controlling the stretching amount to be stable at 1% to 2%, avoiding forced stretching. Even better, a high-precision tension sensor and servo motor are used in a closed-loop linkage to collect the real-time tension of the electrode, dynamically fine-tuning the winding and unwinding speeds, maintaining a constant micro-tension throughout the process, strictly limiting the plastic stretching to the 1% to 2% range, and avoiding excessive or insufficient stretching. Micro-stretching is applied only when the electrode is in the plastic softening zone after being heated by radio frequency. Once it leaves the heating zone and enters the cooling roller for cooling and shaping, no further tension is applied, ensuring that deformation only occurs in the softening area. The front and rear support rollers and traction rollers maintain high-precision parallelism, ensuring that the electrode feed is free from deviation and local stress concentration, and ensuring that the 1% to 2% plastic elongation is uniform throughout the entire range and that the lateral and longitudinal deformations are consistent.

[0026] To stabilize the heating temperature of the blank area within the narrow range allowed by the process and avoid local overheating or underheating, in a more preferred embodiment of the present invention, closed-loop PID feedback control is implemented on the ultra-high frequency radio frequency power supply and the active water-cooled magnetic flux shielding plate 2 based on the temperature data collected by the temperature sensor 7. A high-precision temperature sensor is deployed at the heating station in the blank area of ​​the electrode to collect the real-time temperature signal of the electrode surface, which is then converted into a standard electrical signal and transmitted to the system PLC main control unit. The temperature sensor includes an infrared temperature sensor. The main control unit incorporates a PID control algorithm, comparing the collected actual temperature with the set process target temperature and automatically calculating the output adjustment amount. Based on the PID calculation results, the output power, frequency, and impedance matching parameters of the ultra-high frequency radio frequency power supply are adjusted in real time, dynamically changing the heating energy output of the transverse magnetic flux inductor to achieve real-time fine-tuning of the electrode heating temperature. Alternatively, the main control unit can also incorporate a neural network algorithm, which, after training, can be used to generate feedback signals. Based on temperature fluctuations and changes in electromagnetic field load, the internal cooling water flow rate, inlet water temperature, and water cooling circulation pressure of the shielding plate are synchronously and in a closed-loop manner to precisely control the heat dissipation rate and magnetic field shielding effectiveness of the shielding plate, maintaining a stable magnetic field distribution and heat dissipation state. Through real-time PID closed-loop correction, temperature drift caused by fluctuations in electrode thickness and changes in production line speed is suppressed, stabilizing the heating temperature of the blank area within the narrow range allowed by the process, avoiding local overheating or underheating. Precise temperature control prevents coating thermal decomposition damage, strictly controlling the electrode temperature within the tolerance threshold of the PVDF binder, effectively preventing binder aging, thermal decomposition, coating powdering, and microcracks caused by overheating, protecting the electrode structure and electrochemical performance. Dynamic adaptive magnetic field shielding and heat dissipation adjust the working state of the water-cooled magnetic flux shielding plate in real time according to process conditions. This stabilizes stray magnetic flux shielding, suppresses megahertz tip discharge, and promptly removes eddy current heat generated by the shielding plate itself, preventing heat accumulation and thermal drift from affecting heating accuracy. Full-process automatic closed-loop control is achieved, eliminating the need for manual frequency, power, and water cooling adjustments. It is suitable for continuous high-speed production lines, ensuring uniform heat treatment quality for entire rolls and batches of electrodes, reducing defect rates and process debugging costs.

[0027] To optimize the coupling range for heating the transverse flux inductor 1, maximizing magnetic field penetration and eddy current excitation efficiency, and ensuring sufficient and uniform heating of the blank area, such as... Figure 3As shown. In a more preferred embodiment of the invention, the gap between the transverse flux sensor 1 and the battery electrode 3 is set to 2 to 3 mm by adjusting multiple support rollers 4. This extremely small and uniform air gap of 2-3 mm allows multiple sets of support rollers 4 to be fixed to the frame in a straight line. Using the bottom surface of the transverse flux sensor 1 as a reference surface, precise leveling is performed using a dial indicator and feeler gauge to ensure that the generatrices of all support rollers 4 are at the same horizontal height. Each set of support rollers 4 is equipped with an up-and-down fine-tuning screw and a locking mechanism. The height of each roller is finely adjusted, and the distance between the sensor and the battery electrode 3 is measured using a feeler gauge to accurately set and lock it at 2-3 mm. After adjustment, the positioning screw is tightened to prevent displacement during operation. An excessively small air gap can easily cause tip discharge and corona arcing under megahertz high-voltage resonance. An excessively large air gap results in severe magnetic field attenuation and heating failure. Practice has shown that the optimal range of 2-3 mm avoids the risk of arcing from a spatial structure perspective, protecting the electrode coating from electric shock damage.

[0028] The present invention also discloses an apparatus for performing the above-described method for removing wrinkles in the blank area of ​​a battery electrode sheet using transverse magnetic flux radio frequency induction heating. The apparatus includes an ultra-high frequency radio frequency power supply, a transverse magnetic flux sensor 1, and an active water-cooled magnetic flux shielding plate 2. The ultra-high frequency radio frequency power supply is used to generate megahertz-level radio frequency signals, and injects megahertz-level radio frequency energy into the transverse magnetic flux inductor 1 without reflection after impedance matching. The transverse magnetic flux sensor 1 is used to generate transverse magnetic lines of force that penetrate the plane of the battery electrode 3 vertically, so that the eddy current forms a closed loop in the XY plane of the battery electrode 3 and heats the blank area of ​​the battery electrode 3 at a fixed point. The active water-cooled magnetic flux shielding plate 2 is fixedly installed on both sides of the transverse magnetic flux sensor 1 perpendicular to the direction of motion. It is used to generate a reverse magnetic field to shield the magnetic flux by inducing strong eddy currents, and at the same time, it can dissipate the heat of the eddy currents through the internal forced water-cooling channel 8. Multiple support rollers 4 are used to maintain a constant gap between the transverse magnetic flux sensor 1 and the battery electrode 3; Temperature sensor 7 is used for feedback control to control the heating of the blank area of ​​the battery electrode 3 to a softened state; Production line winding mechanism 5 is used to induce plastic stretching in the softened zone; The freezing roller 6 is used to quench the battery electrode 3.

[0029] This invention also discloses an apparatus for implementing the above-mentioned method for wrinkle removal in the blank area of ​​the battery electrode. The apparatus comprises an ultra-high frequency radio frequency power supply, a transverse magnetic flux inductor 1, an active water-cooled magnetic flux shielding plate 2, multiple support rollers 4, a temperature sensor 7, a production line winding mechanism 5, and a freezing roller 6. The ultra-high frequency radio frequency power supply generates a megahertz-level radio frequency signal, which, after impedance matching, is losslessly input to the transverse magnetic flux inductor 1. This generates transverse magnetic lines of force, causing eddy currents to form a closed loop in the XY plane of the battery electrode 3, achieving point-to-point heating of the blank area of ​​the battery electrode 3. The active water-cooled magnetic flux shielding plate 2 is located on both sides of the transverse magnetic flux inductor 1, generating a reverse magnetic field to shield the magnetic flux and dissipating eddy current heat through an internal water-cooling channel 8. Multiple support rollers 4 maintain a constant gap between the inductor and the battery electrode. The temperature sensor 7 provides temperature feedback to heat the blank area of ​​the battery electrode 3 to a softened state. The production line winding mechanism 5 then causes the softened area to undergo plastic stretching, and finally, the freezing roller 6 completes the quenching heat treatment of the battery electrode. This device effectively eliminates residual stress and wrinkle defects generated during electrode rolling and slitting, prevents coating micro-cracks, powder shedding, and electrode breakage, and improves the overall flatness, dimensional stability, and structural integrity of the electrode. It is suitable for online annealing and wrinkle removal operations on continuous battery electrode production lines, with high process precision, good safety, and strong mass production applicability.

[0030] To avoid problems such as core magnetic saturation, hysteresis loss, and eddy current heating of the core itself, this invention is suitable for megahertz ultra-high frequency operation, exhibiting low temperature rise, small thermal drift, and stable long-term operation. In a more preferred embodiment, the transverse flux inductor 1 adopts a coreless structure, vertically facing the blank area of ​​the battery electrode. The transverse flux inductor 1 is entirely composed of a coreless hollow coil structure, without the addition of silicon steel sheets, ferrite, or other magnetic cores. It is formed solely by winding a hollow conductor using a hairpin or planar coil method, with a hairpin planar coil preferred. The coreless inductor is vertically positioned facing the blank area of ​​the battery electrode 3, with the coil's magnetic flux action surface vertically facing the electrode surface, allowing the generated transverse magnetic lines of force to penetrate the electrode plane vertically. Symmetrically arranged with active water-cooled flux shielding plates 2 on both sides, and supported by rollers 4 to fix the feeding height of the battery electrode 3, a constant small air gap of 2-3 mm is maintained between the coreless inductor and the electrode, ensuring the coil's magnetic field is directionally focused on the narrow blank area. For example, in the industrial ISM band with a target operating frequency of 13.56MHz, the following parameters were measured using a vector network analyzer: equivalent inductance L, equivalent series resistance R, parasitic capacitance Cp, and operating point input impedance Z = R + jX for the coreless hairpin coil. An L-type or π-type dual adjustable impedance matching network architecture was adopted to adapt to the megahertz coreless coil. The impedance deviation under both no-load and electrode-load conditions was recorded, and a matching adjustment margin was reserved. High-frequency high-voltage ceramic adjustable capacitors and non-inductive high-frequency inductors were used to withstand the megahertz high-frequency resonant voltage and large current. All components were selected as low-parasitic, high-frequency dedicated surface-mount or discrete components to reduce distributed parameter interference. The matching network capacitance was adjusted to offset the inductive reactance of the coreless coil, making the load operate at the series resonant point, with the imaginary reactance approaching 0. The series and parallel capacitance values ​​of the network were finely adjusted to accurately transform the resonant pure resistive impedance to 50Ω, perfectly matching the output impedance of the ultra-high frequency RF power supply.

[0031] Because sharp right angles easily lead to electric field concentration in megahertz high-frequency high-voltage fields, inducing corona discharge and sharp-point arcing, this invention aims to completely eliminate discharge induction factors structurally and ensure safe operation in high-frequency electromagnetic fields under narrow air gaps. It also effectively prevents sharp-point discharge from breaking down the air and burning the PVDF coating on the electrode, preventing coating ablation, carbonization, and powdering. In a more preferred embodiment, all edges of the active water-cooled magnetic flux shielding plate 2 facing the transverse magnetic flux sensor 1 are chamfered with a radius of R. All exposed edges, corners, and sharp corners of the active water-cooled magnetic flux shielding plate facing the transverse magnetic flux sensor are machined into rounded chamfers with a fixed chamfer radius of 100mm ≥ R ≥ 3mm, without retaining any right angles, sharp angles, or burr edges. In a more preferred embodiment, the device also includes a control module. The temperature sensor 7 is electrically connected to the control module, which receives the temperature signal transmitted by the temperature sensor 7 and triggers control signals to the ultra-high frequency radio frequency power supply and the active water-cooled magnetic flux shielding plate 2. Sharp edges can easily generate localized high-density eddies and localized overheating. Rounded corners make the eddies more evenly distributed, and together with the internal water-cooling channels, they can prevent localized hot spots and thermal drift on the shielding plate, thus improving the long-term stability of the system.

[0032] The present invention also discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the above-described method for wrinkle removal in the blank area of ​​a transverse magnetic flux radio frequency induction heating battery electrode.

[0033] The present invention also discloses a machine-readable storage medium storing instructions for causing a machine to perform the present invention, as described above, the method for removing wrinkles in the blank area of ​​a battery electrode with transverse magnetic flux radio frequency induction heating.

[0034] In the above embodiments, the descriptions of each embodiment have different focuses. Parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for removing wrinkles in the blank area of ​​a transverse magnetic flux radio frequency induction heating battery electrode, characterized in that, The method for removing wrinkles in the blank area of ​​the transverse magnetic flux radio frequency induction heating battery electrode includes: Step S1: A megahertz-level radio frequency signal is generated by an ultra-high frequency radio frequency power supply. The megahertz-level radio frequency energy is injected into the transverse magnetic flux inductor (1) without reflection after impedance matching. The transverse magnetic flux inductor (1) generates transverse magnetic lines of force that penetrate the plane of the battery electrode (3) vertically, so that the eddy current forms a closed loop in the XY plane of the battery electrode (3) and heats the blank area of ​​the battery electrode (3) at a fixed point. Step S2: Using an active water-cooled magnetic flux shielding plate (2), a reverse magnetic field is generated by induced strong eddy currents to shield the magnetic flux, while the heat of the eddy currents can be dissipated through the internal forced water-cooling channel (8). Step S3: A constant gap is maintained between the transverse magnetic flux sensor (1) and the battery electrode (3) by multiple support rollers (4); the blank area of ​​the battery electrode (3) is heated to a softened state by feedback control through a temperature sensor (7); the softened area is induced to plastically extend by the production line winding mechanism (5); and the battery electrode (3) is quenched by a freezing roller (6) to complete the heat treatment process of the battery electrode (3).

2. The method for removing wrinkles in the blank area of ​​a battery electrode sheet using transverse magnetic flux radio frequency induction heating according to claim 1, characterized in that, The surface temperature of the freezing roller (6) is 20 to 50 degrees Celsius.

3. The method for removing wrinkles in the blank area of ​​a transverse magnetic flux radio frequency induction heating battery electrode according to claim 1, characterized in that, The production line winding mechanism (5) induces 1% to 2% plastic elongation in the softened zone.

4. The method for removing wrinkles in the blank area of ​​a transverse magnetic flux radio frequency induction heating battery electrode as described in claim 1, characterized in that, Based on the temperature data collected by the temperature sensor (7), closed-loop PID feedback control is performed on the ultra-high frequency radio frequency power supply and the active water-cooled magnetic flux shield (2).

5. The method for removing wrinkles in the blank area of ​​a transverse magnetic flux radio frequency induction heating battery electrode according to any one of claims 1-4, characterized in that, By adjusting multiple support rollers (4), the gap between the transverse flux sensor (1) and the battery electrode (3) is set to 2 to 3 millimeters.

6. An apparatus for performing the wrinkle removal method for the blank area of ​​a battery electrode sheet using transverse magnetic flux radio frequency induction heating as described in any one of claims 1-5, characterized in that, The device includes an ultra-high frequency radio frequency power supply, a transverse magnetic flux sensor (1), and an active water-cooled magnetic flux shield (2). The ultra-high frequency radio frequency power supply is used to generate megahertz-level radio frequency signals and inject megahertz-level radio frequency energy into the transverse magnetic flux inductor (1) without reflection after impedance matching. The transverse magnetic flux sensor (1) is used to generate transverse magnetic lines of force that penetrate the plane of the battery electrode (3) vertically, so that the eddy current forms a closed loop in the XY plane of the battery electrode (3) and heats the blank area of ​​the battery electrode (3) at a fixed point. The active water-cooled magnetic flux shielding plate (2) is fixedly installed on both sides of the transverse magnetic flux sensor (1) perpendicular to the direction of motion. It is used to generate a reverse magnetic field to shield the magnetic flux through the induced strong eddy current, and can dissipate the heat of the eddy current through the internal forced water cooling channel (8). Multiple support rollers (4) are used to maintain a constant gap between the transverse flux sensor (1) and the battery electrode (3); Temperature sensor (7) is used for feedback control to control the heating of the blank area of ​​the battery electrode (3) to a softened state; Production line winding mechanism (5) is used to induce plastic stretching in the softened area; A freezing roller (6) is used to quench the battery electrode (3).

7. The apparatus according to claim 6, characterized in that, The transverse magnetic flux sensor (1) adopts a coreless structure and is perpendicular to the blank area of ​​the battery electrode (3).

8. The apparatus according to claim 6, characterized in that, The active water-cooled magnetic flux shield (2) has chamfers with a radius of R on all edges facing the transverse magnetic flux sensor (1).

9. The apparatus according to any one of claims 6-8, characterized in that, The device also includes a control module. The temperature sensor (7) is electrically connected to the control module. The control module is used to receive the temperature signal transmitted by the temperature sensor (7) and trigger control signals to the ultra-high frequency radio frequency power supply and the active water-cooled magnetic flux shield (2).

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for removing wrinkles in the blank area of ​​the transverse magnetic flux radio frequency induction heating battery electrode as described in any one of claims 1-5.

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