Facile synthesis of polyaniline-supported halide perovskite nanocomposite (KCuCl₃/PANI) as potential electrode material for supercapacitor

Metal halide perovskites have gained significant interest for next-generation supercapacitor electrode materials because of their high electronic and ionic conductivity. The researchers have been mainly focused on halide perovskites materials for solar cells and light-emitting diodes, but their use in energy storage applications is found limited. Also, the conducting polymer, specifically polyaniline (PANI), is an efficient material for increasing the pseudocapacitive properties of electrode materials. Here, we have synthesized potassium copper chloride (KCuCl₃) and PANI-based halide perovskites composites by solvothermal and antisolvent route in the ambient environment and determined the physical as well as the electrochemical properties, that are strongly dependent on the preparation method and PANI. Monoclinic phase of KCuCl₃ was confirmed by XRD diffraction spectra and EDX analysis confirm the existence of K, Cu, Cl, and C elements in prepared samples. The BET results showed the higher surface area (13.538 m²/g), pore size (14.56 nm), and pore volume (0.0038 cc/g) of the electrode synthesized by the solvothermal method. Our electrochemical measurements results showed that PANI-based electrodes have a higher specific capacitance of 1757 and 1297 F/g than simple electrodes in 1.0 M KOH electrolyte at 5 mV/s. Furthermore, PANI modified electrodes exhibited substantial enhancement in cyclic stability over 97 and 96% after 3000 cycles. The PANI-based electrodes (R1P and R2P) also have high specific capacitance (2434, 1183 F/g), energy density (438.12, 212.94 Wh/Kg), and power density (1.6, 1.55 W/kg) at a current density of 0.2 A/g. Moreover, superficial, and scalable synthesis of metal halide perovskite and PANI-based composites electrodes can be used efficiently for next-generation supercapacitors.