Study on friction-electrification coupling in sliding-mode triboelectric nanogenerator

Triboelectric nanogenerator (TENG) is regarded as a revolutionary technology for harvesting clean and sustainable energy with low cost. Here, sliding-mode TENGs based on both graphene sheets embedded carbon (GSEC) and amorphous carbon (a-C) films were designed and their friction-electrification coupling properties were studied. The GSEC and a-C films were fabricated by electron irradiation assisted physical vapor deposition in an electron cyclotron resonance (ECR) plasma system. A novel testing platform that can simultaneously measure friction force, output voltage and output current was designed and assembled for studying the friction-electrification coupling of sliding-mode TENG. In the case of GSEC and a-C films slid against Polytetrafluoroethylene (PTFE) film, the open-circuit output voltage, the short-circuit output current density, the peak power density and the maximum instantaneous energy conversion efficiency were 13.5 V, 0.35 mu A/cm(2), 0.63 mW/cm(2) and 8.61% for the GSEC film based TENG, and 8.5 V, 0.24 mu A/cm(2), 0.5 mW/cm(2) and 7.71% for the a-C film based TENG, respectively. The results implied that the GSEC film exhibited a higher electric output performance compared with the a-C film. The origin of high electric output performance of the GSEC film based TENG was ascribed to the edge and channel effects of graphene sheets. These findings shed light on the application of carbon films in friction-induced nanoenergy field.