Macro-superlubric triboelectric nanogenerator based on tribovoltaic effect

Summary

Reducing the coefficient of friction (COF) and wear rate is significant for triboelectric nanogenerators (TENGs). Here, we devised a new macroscale superlubric triboelectric nanogenerator (SL-TENG) that can withstand high-contact stress with ultralow COF (<0.01) and ultralow wear rate based on a hydrogenated diamond-like carbon (DLC) film from the tribological perspective. Specifically, the SL-TENG produced an output with the peak short-circuit current of approximately 60 nA and a power density of up to 5.815 W/m² during the friction of DLC versus steel ball with a Hertz contact stress of 1.37 GPa. Moreover, first-principle calculations demonstrate that the ultralow friction on DLC is mainly due to the hydrogen-terminated surface. The SL-TENG can generate direct current (DC) output caused by tribovoltaic effect and can light up several light-emitting diodes (LEDs) without rectification. Online superlubric friction monitoring and early warning can be realized, owing to the close correspondence between tribology and triboelectricity.