Meaning
Electrode positioning during the cell winding or stacking process dictates the size of the safe boundary between anode and cathode active areas. The overhang misalignment represents a deviation from this design offset, where the anode fails to completely cover the cathode edge. This error creates a region of high local current density that compromises cell stability.
Plating Mechanism
Insufficient anode surface at the misaligned boundary prevents incoming lithium ions from intercalating normally. This condition leads to the metallic plating of lithium on the separator interface instead of normal intercalation. Over time, these metallic structures grow into sharp dendrites that can penetrate the separator and trigger short circuits.
The phenomenon accelerates during cold-weather charging when the diffusion rate of lithium into the graphite lattice drops significantly, multiplying the risk of internal thermal runaway.
Defect Detection
Inline imaging during the assembly process identifies positioning errors before the cell is inserted into its housing. Automated X-ray scanners or high-resolution cameras measure the electrode edges to calculate the overhang misalignment at multiple points. Production software automatically rejects any cell that falls outside of the designated dimensional limit.
Quality Standard
Manufacturing specifications define precise tolerances for tension and alignment to prevent shifts during high-speed runs. These rules ensure that the anode overhang remains consistent across both outer layers and inner wraps. Consistent boundaries protect the cell against premature failure during subsequent fast-charging protocols.
