Nickel-Oxide-Doped Polyvinylidene Fluoride Nanofiber-Based Flexible Triboelectric Nanogenerator for Energy Harvesting and Healthcare Monitoring Applications

Triboelectric nanogenerators (TENGs) are renowned for capturing large-scale unused energy from ambient surroundings. A sustainable TENG can meet future energy demands without contaminating our environment. In the present study, we have synthesized nickel oxide nanoparticles (NiO NPs) via the coprecipitation method. Further, NiO NPs were doped with poly­(vinylidene fluoride) (PVDF) (0 to 9 wt % w.r.t. PVDF concentration) to prepare the PVDF-NiO electrospun nanofibrous mat. The output efficiency was calculated in terms of open-circuit voltage (V_oc) and short-circuit current (I_sc). NiO-doped PVDF and thermoplastic polyurethane (TPU)-based TENG generated enhanced performance compared to the pristine PVDF (P-Ni-0)/TPU-based TENG. Among the six combinations of samples fabricated, 7 wt % of NiO-doped PVDF (P-Ni-7)/TPU-based TENG generated the utmost voltage of 252 V, which is almost 22-fold higher than the P-Ni-0/TPU triboelectric pair generated voltage (11.5 V). Similarly, the maximum current achieved was 7.3 μA, which is almost a 9-fold enhancement over the P-Ni-0/TPU triboelectric pair (0.8 μA). The power density of the optimized TENG ((P-Ni-7)/TPU) was 0.86 mW/m², and it was directly used to light up 15 LEDs. Furthermore, a flexible and self-powered P-Ni-7/TPU-based TENG device was demonstrated for real-time biomechanical motion measurements. Overall, this work disclosed a facile technique for doping NiO NPs into a PVDF matrix, and the fabricated TENG demonstrated efficiency when used for mechanical energy harvesting and sustainable power-supplying systems for miniaturized wearable electronic devices.