Enhancing Power Generation in Triboelectric Nanogenerators via Integration of Graphene Nanoplatelets and Polyvinyl Alcohol

Abstract

Triboelectric nanogenerators (TENGs) provide promising power supply solutions by transforming mechanical energy into electrical energy. However, enhancing electrical performance of TENGs is essential for their widespread practical applications and commercialization. In this study, we fabricated TENGs in vertical contact-separation mode using a tribopositive material-polyvinyl alcohol (PVA) slime-which is biocompatible, flexible, and wearable, decorated with graphene nanoplatelets (GnPs), and paired with tribonegative silicone. We analyzed the correlation between the electrical performance of the TENGs and the inherent triboelectric properties of the constituent material, including the evaluation of surface roughness, the measurement of the contact potential difference (CPD), and the material's dielectric constant. The incorporation of GnPs increased the dielectric constant of the composite material and its electron-donating tendency, thus, increasing the contact potential difference. The GnPs concentration of 1 wt% was identified as the optimal value, resulting in a 42% increase in power density. The 1 wt% GnPs@PVA&Silicone TENG exhibited an open-circuit voltage of 718 V and a peak power density of 15.3 W/m2. This study sheds light on enhancing the energy harvesting efficiency of TENGs through the utilization of biocompatible tribopositive and tribonegative materials.