Current Collector Burr Height

Fabrication Tolerance

Sharp edges originate from the slitting process where circular blades shear the aluminum or copper sheet to width. Manufacturers inspect current collector burr height to prevent micro-shorts that develop when the separator experiences mechanical penetration. Controlling this protrusion prevents internal degradation that occurs over repeated charge cycles as localized dendrites form at the puncture site.

Excessively high measurements signal that the slitting knives require sharpening or that the gap settings deviate from the specification. Engineering teams establish these limits to ensure that the foils remain smooth enough to permit high-speed processing without causing downstream equipment jams or tearing the web.

Measurement Protocol

Optical microscopy or laser scanning profilometry provides the standard verification for the vertical extension of the edge deformation. Technicians verify the current collector burr height by imaging the cross section of the slit edge at regular intervals along the coil. This assessment requires a calibrated reference plane to establish the baseline of the flat foil surface before quantifying the rise of the metallic spike.

Precision in this evaluation depends on the capture of the highest point along the jagged edge. Data logs show that deviations appear most frequently toward the final meters of a production run as blade edge wear accumulates.

Electrical Consequence

Voltage stability across the cell depends on the avoidance of contact between the cathode and anode through the separator. A neglected current collector burr height creates a permanent site for leakage current that manifests as high self-discharge rates. Long term performance suffers when the edge roughness exceeds ten percent of the separator thickness.

This dimensional constraint governs the reliability of the insulation layer within the battery housing.