Novel ternary nanocomposites as a powerful catalyst for high-performance all-solid-state asymmetric supercapacitors

Supercapacitors are a fundamental technology in electrical energy storage because of their high performance and cycling. In this study, using a conductive type of nanocomposites, we tested electrode designs in the application of supercapacitors, obtaining valuable results in energy capacity and power density. MnO₂-Fe₂O₃/N-doped graphene nanoribbons (MFNGN) were prepared by an efficient multistep approach. The synthesized result demonstrated that the large surface area of the nanocomposite causes faster transfer of ions and electrons and increases the internal electronic fields with interconnecting nanoscale pore channels for ion transport to adjust the electronic structures. High surface area-to-volume ratio also provides numerous active sites for electrochemical reactions. Consequently, surface area makes available active sites for electron transfer process and also improved the electrochemical performance of the electrodes by improving the electron transfer rate charge transfer capacity. The results demonstrated good cycling stability, with 87.56% of the initial capacity retained after 10,000 cycles at 5.0 A·g⁻¹. Furthermore, a hybrid supercapacitor that uses the MFNGN as a positive electrode and active carbon (AC) as a negative electrode was created. This combination resulted in an asymmetric supercapacitor (ASC) that exhibited exceptional performance. Specifically, it achieved a remarkable specific capacitance of 770.0 F·g⁻¹ when subjected to a current density of 1.0.