A corn-inspired structure design for an iron oxide fiber/reduced graphene oxide composite as a high-performance anode material for Li-ion batteries

Abstract

In this paper, we successfully synthesized iron oxide (Fe2O3) fiber/reduced graphene oxide (rGO) composites with a "corn" structure by an electrospinning technique assisted by annealing treatment and a far infrared reduction process. The special structure consists of Fe2O3 fibers as the "corncob" completely protected by multilayer rGO as the "sepal". Natural void space between the Fe2O3 fibers and rGO allows for the expansion of Fe2O3 upon lithiation; the good surface area and unblocked channels in the Fe2O3 fiber facilitates fast diffusion of Li+. An electrode with such structure shows excellent capacity (1085.2 mA h g-1 at 0.1 A g-1), and cycle life (407.8 mA h g-1 at 5 A g-1 for 1500 cycles with good coulombic efficiency). This is the longest cycle life for Fe2O3-based anode materials with excellent rate capability (e.g., >400 mA h g-1 at 5 A h g-1). In addition to Fe2O3, this "corn" structure can also be applied to other high capacity anode materials for next generation Li-ion batteries to improve cycle life and coulombic efficiency.