Hierarchical a-Fe2O3/MnO2/rGO ternary composites as an electrode material for high performance supercapacitors application

Transition Metal oxide decorated graphene nanosheets have accumulated a lot of consideration due to their potential applications in electrochemical energy storage devices especially in supercapacitors (SCs). Nano structured mixed multi-metal oxides have been employed as promising electrodes for creating more active site for electron transfer. All-solid-state asymmetric supercapacitors (ASC) have significant theoretical capacitance, good rate capability, and excellent cycling stability suitable for energy storage device fabrication with optimum energy and power density. Here, we demonstrate a Solvothermal route to synthesis ternary alpha-Fe2O3/MnO2/rGO composites.. The hybrid ternary composites in 3-electrode configuration showed maximum capacitance of 447 F g(-1) at optimum current density at1Ag(-1) and 96 % of capacitance retention after 10,000 GCD cycles at 10 A g(-1 & nbsp;)in an alkaline medium. The fabricated ASC device with ternary composites (positive) and negative electrodes (rGO) separated by PVA/KOH gel-electrolyte separator exhibits maximum cell voltage of 1.4 V with high specific capacitance of 97 F g(-1) at 1 A g(-1). Additionally, the assembled device delivered a high energy density of 13.2 W h kg(-1 & nbsp;)and a high power density of 6124 W kg(-1) with an excellent capacitance retention of 92% and columbic efficiency of 96 % preserved over 5000 cycles at 10 A g(-1 & nbsp;)with good reversibility. Besides, the Solvothermal strategy supports for the fabrication of metal oxide could be applicable for other metal oxide electrode materials preparation.

Automated summary

Transition metal oxide decorated graphene nanosheets have shown great potential in electrochemical energy storage, especially in supercapacitors. In this study, ternary alpha-Fe2O3/MnO2/rGO composites were synthesized using a solvothermal route and demonstrated excellent performance in energy storage devices.