Fabric‐Based Wearable Self‐Powered Asymmetric Supercapacitor Comprising Lead‐Free Perovskite Piezoelectrodes

Abstract The demand for flexible supercapacitor sustaining green energy can go a long way in mitigating the issue of no power source in wearable electronics. Herein, a novel strategy is used to develop a self‐charging supercapacitor using lead‐free perovskites as piezoelectrodes and polyvinyl alcohol‐potassium hydroxide (PVA‐KOH) film as ionogelled electrolyte. This approach is unique as the existing conventional self‐powered devices are based only on piezoelectric electrolytes. The all‐solid‐state supercapacitor is asymmetric, with nickel stannate (NiSnO₃) acting as the positrode and ferrous stannate (FeSnO₃) as the negatrode. These materials are non‐toxic, environment‐friendly, and bio‐compatible, making them suitable for wearable electronics. The value of specific capacitance of FeSnO₃ is 2853 F g^–1, the highest among the perovskite‐based electrodes. The self‐charging characteristics of the fabricated supercapacitor are analyzed by bending, twisting, and subjecting it to compressive forces of varying magnitude. A maximum voltage of 266 mV is recorded through the self‐charging phenomenon. All these tests approve that the fabricated perovskite‐based supercapacitor is highly flexible, robust, stable, and has considerable electrochemical and self‐charging potential. The present study focuses on understanding the piezoelectric effect in self‐charging supercapacitors and offering a viable power option for self‐powered wearable devices in the future.