Effects of Carbon Nanoparticles on Triboelectro‐Induced Surface Defects

Electrical surface damage caused by current leakage is a critical challenge in high‐performance applications such as electric vehicle (EV) drivetrains and wind turbine gearboxes. To address this issue, we investigated a lithium‐based grease blended with carbon nanoparticle (CNP) additives to improve electrical conductivity and mitigate surface damage. Electrochemical impedance spectroscopy confirmed that nanoparticle inclusion significantly reduced grease impedance, enhancing its ability to conduct charge through the contact interface. Tribological analysis revealed that the presence of CNPs suppressed electrical pitting, reduced friction, and altered the dominant wear modes from electrothermal degradation to more benign adhesive wear. Notably, the pitting density decreased from 9.4% in the base grease to just 2.5% with 1 wt% CNPs, confirming the effectiveness of nanoparticles in suppressing localized electrical discharges. The grease formulation containing 0.5 wt% CNPs provided the optimal balance, minimizing surface damage while maintaining conductivity. Mechanistically, the CNPs form conductive percolation pathways within the grease, allowing current to pass through the lubricant film and thereby preventing localized discharge and thermal damage at asperity junctions. This work opens an alternative route for designing electrically functional greases that mitigate current‐induced damage, extending component life in high‐performance electrified environments.