3D Printed Flexible Piezoelectric Self‐Charging Supercapacitors for Self Powered Electronics

ABSTRACT The increasing demand for autonomous power systems in wearable and smart electronics has driven the development of integrated devices capable of simultaneous energy harvesting and storage. Here, a flexible piezoelectric self‐charging supercapacitor (PSSC) is developed by integrating a high‐performance supercapacitor with a direct ink writing (DIW)‐fabricated three‐dimensional PVDF‐ZnO piezoelectric architecture. The supercapacitor, based on binder‐free MnO 2 nanosheets grown on conductive carbon fiber cloth, delivers an areal capacitance of 0.86 F cm − 2 at 2 mA cm − 2 , with an energy density of 0.119 Wh cm − 2 and a power density of 1 W cm − 2 . It also exhibits excellent electrochemical durability, retaining 94.01% capacitance after 10,000 cycles, along with stable performance under repeated mechanical deformation. The DIW‐fabricated piezoelectric structure acts as both a separator and energy harvesting layer, generating a piezopotential under mechanical deformation that drives ion migration and charges the supercapacitor to a stored voltage of up to 866 mV. The three‐dimensional architecture enhances strain‐induced polarization, electrolyte accessibility, and ion transport, thereby improving electromechanical‐electrochemical coupling. These results suggest that the proposed PSSC is a viable flexible power unit for future wearable electronic applications.