Highly efficient and stable negative electrode for asymmetric supercapacitors based on graphene/FeCo₂O₄ nanocomposite hybrid material

Abstract

The integration of two-dimensional (2D) reduced graphene oxide (rGO) and binary metal oxide in a single electrode for asymmetric supercapacitors (ASC) is promising for overcoming the challenges driven by increasing energy-storage demands. In present work, we proposed a novel rGO/FeCo₂O₄ hybrid electrode as a negative electrode for asymmetric supercapacitors (ASC). Briefly, we engineered 3-dimensional nanocomposite materials by decorating FeCo₂O₄ nanoparticles on rGO nanosheets using facile strategy. Owing to the strong chemical bonding between the FeCo₂O₄ nanoparticles and rGO nanosheets, as-prepared rGO/FeCo₂O₄ hybrid electrode shows an ultrahigh specific capacitance of 1710 F/g on the negative potential side. Later, asymmetric supercapacitor was assembled using MnO₂ nanowires as positive electrode and rGO/FeCo₂O₄ hybrid as negative electrode, respectively. The proposed device achieved a maximum specific capacitance of 260 F/g with a specific energy of 67.5 Wh/kg and exhibited excellent cycling performance (96.02% capacity retention after 5000 cycles). Thus, the proposed design of the high-energy ASC is promising for next-generation energy-storage devices being developed for modern consumer applications.