Fullerene-Enhanced Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) convert mechanical energy, e.g., from human motions, into electrical power. The mechanical force brings two triboelectric materials with different electron affinities into contact, resulting in a voltage that can be used to power a device. Although progress has been made in identifying high-performance triboelectric materials (e.g., polytetrafluoroethylene, MXenes, polyethylene terephthalate (PET), graphene-impregnated polymers, and polyimide), the search for better triboelectric materials continues in order to harvest mechanical energy efficiently. Here, it is demonstrated that the output performance of a TENG can be enhanced by coating its triboelectric material surface with an important class of carbons, viz., zero-dimensional C(60)fullerene, which is known for its high electron affinity. Specifically, a C(60)fullerene-based TENG (F-TENG) is fabricated and evaluated that supports a high open-circuit voltage of approximate to 1.6 kV, short-circuit current of approximate to 100 mu A, instantaneous peak power density of approximate to 38 W m(-2), and charging of a 1 mu F capacitor to 180 V under 8 min. Because of the superior power output of the F-TENG, a digital watch can be powered continuously in real-time, a task that cannot be performed with a similar-sized TENG comprising PET and polyimide. Notably, a novel methodology based on the analysis of the TENG output waveforms is presented for determining the triboelectric charge, which can then be used to rank the electrode material in the tribolelectric series.