Facile and scalable synthesis of nanostructured Fe2O3 using ionic liquid-assisted ball milling for high-performance pseudocapacitors

Abstract

In this study, we report that ionic liquid (IL)-assisted ball milling of iron precursors in the absence of any reagent resulted in the scalable production of IL/Fe2O3 hybrids with a favourable morphology (high surface area of 202 m(2)/g and pore size of 40nm) for supercapacitor applications. During ball milling process, ILs are played role as structure guiding templates for construction of rod-like pore containing Fe2O3 and surface functionalities for IL/Fe2O3 hybrids, resulting in good wettability and enhanced ion transfer. These attractive features of IL/Fe2O3 hybrids make them excellent candidate pseudocapacitive electrode materials that exhibit a high specific capacitance of 230 F/g at a current density of 1 A/g, fast and reversible charge/discharge rates (similar to 71% retention at 15 A/g), and excellent long-term cycle stability (similar to 100% retention over 10000 cycles).