Well‐Balanced Supercapacitive Energy Storage Application and Clean Energy Generation Achieved Through Synergistically Active ZnO/NiO‐Based Composites

The key objective of this work was to fabricate a high‐performance supercapacitor, confirming the preservation of high energy density without compromising the power density. Furthermore, the clean energy harnessing potential was also explored, where the mixed metal oxide, i.e., ZnO/NiO composite, was combined into the polyvinylidene fluoride (PVDF) polymer matrix to develop a piezoelectric nanogenerator (PENG). For the supercapacitor, the highest specific capacitance value of 593 F/g at 1 A/g was observed along with well‐balanced energy density and power density values of 82.36 Wh/kg at 1 A/g and 12,058.82 W/kg at 50 A/g, respectively. A symmetric ZnO/NiO/rGO‐based supercapacitor device was fabricated for the evaluation of real‐life applications, which highlighted its promising performance in energy storage applications. For the ZnO/NiO/PVDF‐based PENG device, an open circuit voltage of approximately 56 V through simple finger tapping was observed, showcasing its outstanding clean energy harvesting capabilities. The PENG device exhibited a power density value of 19.66 kW/m 3 , highlighting its efficacy in translating mechanical energy into electrical energy. This research work presented here provides comprehensive insights about the effective energy storage and harvesting abilities of the ZnO/NiO/rGO‐based supercapacitor and ZnO/NiO/PVDF‐based PENG, paving the way for further developments in sustainable energy applications.