Inbound Lithium Cell Quality Verification and Acceptance Sampling Protocols
Verify inbound cell compliance using ISO 2859-1 sampling, microvolt OCV screening, K-value decay tracking, and UN 38.3 audit chains before pack assembly.
Burr Metrology
Meaning
Microscopic edge dimensional analysis quantifies mechanical defects generated during foil slitting and electrode die-punching operations. Precision optical shear measurement within burr metrology establishes the physical height and lateral width of metallic overhangs along copper and aluminum current collectors. Excessive metal overhangs penetrate thin separator membranes, causing internal micro-shorts and thermal runaways.
Measurements evaluate edge profiles down to single-micron resolution but do not assess coating thickness or active material binder adhesion.
Detection Method
Non-contact laser displacement sensors and high-resolution optical microscopes capture edge profiles immediately after slitting knives cut the coated foil. Automated systems in burr metrology calculate mean burr height alongside peak defect frequency per linear meter of continuous roll. Real-time feedback automatically triggers blade adjustment or replacement schedules before defects exceed safety thresholds.
Failure Prevention
Punctures in separator films originating from sharp metallic edges trigger localized short circuits that degrade cell performance over extended charge cycling. Battery assembly lines deploy burr metrology to enforce maximum allowable burr limits, preventing cell contamination during winding or stacking operations. Clean edge cuts maintain dielectric isolation between positive and negative electrodes.
Blade Wear
Continuous cutting of abrasive cathode slurries degrades slitting tool edges, increasing burr formation rates over operational shifts. Tooling maintenance intervals rely on quantitative burr data to optimize blade re-sharpening schedules.