Facile synthesis of FeS-Fe 3 O 4 nanocomposite: Highly stable & enhanced electrochemical performance in Asymmetric Supercapacitor Applications

Abstract

Over the last decade, researchers have required electrode materials that have more energy density and are highly stable to make the next generation of supercapacitors. This study developed and analyzed a FeS-Fe 3 O 4 nanocomposite as a potential positive electrode material for asymmetric supercapacitors. Structural and morphological analyses were performed using XRD and FESEM, with EDX and EDS mapping. The FeS-Fe 3 O 4 composite worked better than either pure FeS or pure Fe3O4 when tested with a 3 M KOH electrolyte. At 1 A . g -1 , it has a specific capacitance of 464.6 F . g -1 , and at 4 A . g -1 , it has a specific capacitance of 186.9 F . g -1 . The better performance is because FeS conducts electricity better, and Fe 3 O 4 acts like a pseudocapacitor. These two things work together to speed up the movement of ions and the redox processes. We built a supercapacitor that wasn't even. The negative electrode was made of activated carbon, and the positive electrode was made of FeS-Fe 3 O 4 . It can work with a voltage window of 1.4 V. The device had a power density of 699.6 W . kg -1 and an energy density of 46.10 Wh . kg -1 . It had a high power density of 3998.4 W . kg -1 , but it also had a low energy density of 30.17 Wh . kg -1 . After 12,000 charge-discharge cycles, the device still has 98.6 % of its capacitance and about 99.8 % of its coulombic efficiency, which is also good for cycling. The results show that the FeS-Fe 3 O 4 nanocomposite is a very good material for electrodes in energy storage systems that need to be strong and work well.