Lithium battery electrode separator slitting
The Battery Electrode Slitting scenario for lithium batteries consists of a positive electrode (aluminum foil coated with lithium iron phosphate, ternary materials, etc.) and a negative electrode (copper foil coated with graphite, etc.). Pole slice slitting is the process of longitudinally cutting a large and wide pole slice that has been coated and compacted into narrow strips that meet the requirements for cell winding or stacking. Industry core pain point: Burr control: The positive and negative electrode coatings contain extremely hard active substance particles, and the substrate (copper foil/aluminum foil) is extremely thin (only a few microns). If the blade is not sharp enough or the precision is insufficient, the incision will produce metal burrs. Excessive burrs are a key hazard for lithium batteries to self discharge severely and even puncture the separator, causing short circuit explosions. The industry requires that burrs must usually be controlled within $12 \ mu \ text {m} $or even $5 \ mu \ text {m} $. Powder shedding and scratches: Friction during shearing may cause the coating on the edge of the electrode to peel off (powder shedding) or produce wavy edges, affecting the consistency of the battery cell. Extremely high wear: Positive electrode materials (such as ternary materials) have strong abrasiveness, and ordinary steel knives may wear out in a few hours. Henglida's core products and applications: Lithium ion positive and negative electrode slitting tungsten steel disc cutter (round cutter): Henglida uses ultra-fine grain hard alloy (tungsten steel) as the substrate. This material has extremely high hardness and red hardness. Ultimate machining accuracy: Henglida uses high-precision CNC grinding machines to control the edge roughness, thickness tolerance, outer circle runout, and side runout of circular knives at the micrometer level ($\ le 0.002 \ text {mm} $). Ensure that the blade clearance is absolutely uniform during cutting, achieving a perfect cutting surface without burrs, powder loss, or wavy edges. 2、 The battery separator slitting scenario for lithium batteries is a critical safety barrier that isolates positive and negative electrodes and allows ions to pass through, typically made of polyethylene PE, polypropylene PP, or ceramic coated separators. Diaphragm slitting is the process of cutting a large roll of main film into narrow separators that are compatible with different battery specifications. Core pain points in the industry: Extremely thin and easily stretchable: The thickness of the base film is often only $5 \ mu \ text {m} -12 \ mu \ text {m} $, and the material is extremely soft and elastic. High coating wear: Nowadays, ceramic coatings (such as alumina and boehmite) are commonly used for diaphragms to resist high temperatures. These ceramic particles have a strong wear effect on the cutting edge of the blade. Fuzhing and ruffle edges: If the blade is not sharp enough or there are small gaps, the edge of the diaphragm will become hairy, or uneven force will cause "ruffle edges", resulting in poor alignment during winding. Henglida's core products and applications: specialized slitting knives for diaphragm cutting/ceramic diaphragm knives: In response to the strong abrasion of ceramic diaphragms, Henglida provides specially formulated hard alloy blades or blades with superhard nano coatings (such as diamond coating/DLC). Mirror edge: The blade edge is ultra precision ground to achieve mirror level. This enables the blade to instantly cut open the diaphragm like a hot knife cutting butter during high-speed slitting (up to hundreds of meters per minute), avoiding tensile stress, eliminating burrs and fuzzing, and ensuring smooth winding of the diaphragm edge.