Synthesis and electrochemical performance of porous FeCo₂S₄ nanorods as an electrode material for supercapacitor

FeCo2S4 nanorods structure grown onto nickel foam were formed by an easy hydrothermal process in this work. Initially, FeCo Lyared Double Hydroxides (FeCo LDH) nanosheets were realized via the hydrothermal technique. These sheets' precursors were further converted into FeCO2O4 nanosheets by annealing. The FeCo LDH sheet's structure was converted into FeCo2S4 nanorods by a one-step sulfidation process. The results showed that the FeCo2S4 nanorod structure was successfully grown on Ni foam substrate. Electrochemically, the FeCo2S4 nanorods revealed a high specific capacitance of 4035 F g(-1) at 1 A g(-1) as a current density in 6 M KOH solution, with exceptional cycling stability of 80.4% capacitance retention and 100% coulombic efficiency after 5000 cycles. The FeCo2S4/NF// FeCo2S4/NF symmetric device gives the highest specific energy (37.72 W h kg(-1)) at the specific power (603.6 W kg(-1)) at current density 0.5 A g(-1) beside exceptional cycling stability of 80.3% capacitance retention after 5000 charge/discharge cycles and excellent coulombic efficiency of 94%. The outstanding electrochemical characteristics of FeCo2S4 nanorods make them suitable candidate electrode materials for high-performance supercapacitors applications.