Facile synthesis of KMnCl3 halide perovskite based composites with rGO and fullerene (C60) for efficient supercapacitor electrodes

Recently, the family of halide perovskite materials drawn significant attention of scientific community for next generation energy storage devices because of their outstanding features, such as high ionic and electronic conductivity. However, besides energy conversion, their use for energy storage is found to be limited. In this study, an efficient antisolvent approach were employed to synthesize the halide perovskites KMnCl3, and their composites, i.e.; KMnCl3/rGO and KMnCl3/C60, for supercapacitor electrodes. XRD spectra confirm the phase purity with orthorhombic phase, while FE-SEM revealed the porous type morphology of rGO and C60 based composite, facilitating the smooth and fast ions transportation at the electrode. EDX spectra confirmed the presence of the constituent elements. I-V measurements confirmed the high conductivity and low resistivity for rGO and fullerene (C60) based composite, supporting the EIS analysis having low solution and polarization resistance. BET analysis exhibit the mesoporous nature of the fullerene (C60) based sample with surface area (25.3412 m2/g), pore radius (45.3023 nm), and pore volume (0.0038 cc/g), respectively. Further, the CV test confirmed the pesudocapacitive nature, with outstanding stability 95 % over 4000th charging-discharging cycles. GCD test also demonstrated that fullerene (C60) based electrode have high specific capacitance, high power density and energy density (936.67 F/g, 3.1 W/kg, 150.58 Wh/Kg) as compared to other electrodes. The scalable synthesis of halide perovskite-based composites can be effectively used as next generation supercapacitor electrode with enhanced electrochemical performance for real applications in future.