Electrochemical properties of PPy/rGO/NiCoFe₂O₄ composites as advanced electrode materials for supercapacitors: a state-of-the-art review

Due to their high storage capacity, excellent stability, and strong reversibility, supercapacitors are a major focus in current research and development. For a supercapacitor to exhibit these qualities, an effective electrode material is essential. This review explores the synthesis of electrodes using a composite of polypyrrole (Ppy), reduced graphene oxide (rGO), and nickel–cobalt ferrite (Ni-Co ferrite) for supercapacitor applications. The ternary composite exhibits a high specific capacitance of 250 F/g, outperforming binary composites like rGO/MnFe₂O₄, which typically achieve a specific capacitance of 147 F/g. Polypyrrole amorphous structure offers ideal voids for charge storage, while the plate-like rGO enhances charge accumulation. The magnetic nature of Ni-Co ferrite further contributes multifunctional properties, enabling applications in microwave absorption and toxic gas sensing for industrial gases like NH₃ and CO. These characteristics make the PPy/rGO/Ni-Co ferrite composite highly suitable for advanced energy storage, environmental monitoring, and flexible electronics applications.