Application Innovation—Hymson Achieved A Leaping Development On LIB Laser Notching Technology
Laser Notching
Laser notching is a major process involving laser application in LIB electrode manufacturing, which forms tab unilaterally or bilaterally on the metal foil of cathode and anode electrode, providing battery with metallic conductor.
With the fast development of laser notching equipment, integrated machine (such as notching & slitting integrated machine and notching & cutting integrated machine) has been rolled out to the market, further enhancing the efficiency, accuracy and intelligent level of equipment with optimized functional modules.
Hymson High-speed and High-precision Laser Notching Technology for LIB Overcome Electrode Manufacturing Bottleneck in Large Cylindrical Cell
Represented by 4680 battery, 4600s series cylindrical battery, also known as the large cylindrical battery, has been considered as a possible direction for next generation of product. As the core link of large cylindrical battery production line, tab notching with high efficiency and high accuracy holds the key towards product with high performance and safety.
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As a forward-looking industrial player, Hymson has dived into multi-tab process R&D from an early stage. By far, it already developed a highly-matured multi-tab process with LIB mass production experience. Focusing on notching module, laser application and control technology,
Hymson makes intensive study to refine key laser technology for high-speed and high-accuracy tab notching, solving quality NG problems in high-speed multi-tab process, such as tab alignment defect, notching dimension inaccuracy and melt bead.
Multi-section tension control technology Overcome stability pain point for high-speed notching
It has been an industrial research priority, how to deliver laser notching with optimal stability and quality performance in fast production, especially for multi-tab process, which involves stable high-speed cutting with fast response to gradual tab height control and gradual slit width control, leading to more demanding requirements on the tension control technology.
By far, Hymson has resolved key technical difficulties for multi-sect
ion electrode tension control. With the help of laser notching trajectory algorithm, Hymson has constructed simulation model for roller diameter calculation and taper control optimization, achieving matching and linkage of difference speed. Applying this technology into electrode transfer control can effectively achieve stable tension control over the complete electrode web route, reducing occurrence rate of curl edge and burr, and solving problems including electrode breakage, deformation and wrinkles. At the same time, it also increases processing accuracy and defect inspection accuracy of CCD camera, enhancing safety and consistency of laser notching and lowering the production cost.
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This technology delivers stable laser notching performance for production at a speed of 120m/min. It creates small HAZ and burr as well as sound consistency at end face.
In-line defect inspection and in-line high-speed closed-loop control technology Overcome difficulty of closed-loop control over selection, NG removal and notching in high-speed scenario
Laser notching process employs laser cutting device to notch the tab out of electrode. However, as the incoming electrode has intrinsic shape defect and edge measurement error and susceptible to displacement during transfer, it creates a rather noticeable deviation to the final processing position of laser notching device and a relatively high error rate, leading to possible quality NG and relatively lower yield.
According to tab notching process requirement, shape defect of incoming electrode within the defined electrode length range L can be ignored, whereas laser processing trajectory must be adapted to the edge shape if shape defect exceeds L. Therefore, Hymson uses the visual-guided processing system that is based on Wavelet Transfer in LIB electrode manufacturing equipment for edge inspection of incoming web, tab shape following function and auto position control with compensation, overcoming difficulty of closed-loop control over selection, NG removal and notching in high-speed scenario.
Post-notching Electrode Cleaning Technology Improvie Electrode Cleanliness and Safety Performance
Hymson equipment is designed with 5 or above dedusting processes (including negative pressure for overhanging laser notching, air knife for both sides, brush, ultrasonic, and magnetic bar) to ensure electrode cleanliness and solve technical pain points such as dust accumulation during production, incomplete laser notching, electrode break and defects by foreign bodies, laying a sound foundation for clean and stable production of high-quality product.
?Negative pressure dust removal for overhanging laser notching utilizes air flow to evacuate cutting dust. Based on laser notching features, Hymson designed the omni-seal overhanging laser notching structure with side dust removal mechanism for effective dust removal and flat belt together with brush mechanism for highly efficient scrap collection.
Based on in-depth research on dust removal effect and air speed application of different-sized particles, Hymson successfully developed an air knife dust removal system with fluid simulation for design optimization. The dust evacuation inlet employs 3D printing technology to create a smooth and curvy internal surface to reduced dust adhesion, effectively improving electrode cleanliness. Furthermore, dedusting pipeline is configured with closed-loop monitoring function and FFU air purge with air backflow from machine bottom to secure a high-level control over tab notching dust (residual particle≤10μm).
Hymson laser notching solution has make breakthroughs on key technical pain points, such as auto un-/re-winding technology, high-speed auto splicing, multi-section tension control of electrode, tab dimension accuracy, and in-line high-speed closed-loop control. At the same, the introduction of PLC and MES drives LIB manufacturing to upgrade from mass production to quality production in TWh era. In the future, Hymson will continue to explore the innovative solutions with more initiatives, meeting the new challenges and new requirements in EV (electric vehicle) and ESS (energy storage system) sectors.