Tungsten Carbide Circular Slitting Knives for Lithium Battery Electrode Foil

For lithium-ion battery electrode slitting, the cutting bevel must be polished to Ra ≤ 0.05μm (mirror finish) and verified for zero notches under 400× magnification. Any surface irregularity above this threshold generates micro-metallic particles that contaminate ISO Class 7 dry-room environments and can penetrate the separator, causing internal short-circuit in the finished cell.

For 6–12μm Cu anode foil, the upper/lower knife clearance should be set at 0.002–0.005mm (2–5% of foil thickness). Clearance below this range causes burr formation; above it results in foil wrinkling and rewind telescoping. Our matched pairs are pre-verified to your specified clearance and supplied with a dimensional data sheet for consistent line-side installation.

Both foil types benefit from submicron WC-Co (≤0.5μm grain, HRA 91–93). For Al cathode foil, the hard oxide surface layer is the primary abrasion driver — a standard K10/K20 carbide grade provides acceptable edge life. For Cu anode foil, the priority shifts to achieving the lowest possible surface roughness (Ra ≤ 0.05μm) to prevent adhesive transfer and foil marking at the cut edge.

On a standard 600mm-wide foil slitting line running 80 m/min, submicron WC-Co knives typically sustain acceptable edge quality for 4–6 months of continuous operation before regrinding is required. Edge degradation appears first as increased cut-edge roughness (Ra climbing above 0.1μm) visible under SEM inspection, not as catastrophic chipping. We offer a regrinding service with full dimensional re-certification.