Ni(OH)2 nanosheet @ Fe2O3 nanowire hybrid composite arrays for high-performance supercapacitor electrodes

Abstract

We demonstrate the design and fabrication of novel hybrid nanoarchitectures using facile coating of ultrathin Ni(OH)<inf>2</inf> nanosheets onto α-Fe<inf>2</inf>O<inf>3</inf> nanowire arrays directly grown on Fe foils toward achieving high specific capacitance, high-energy and high power density, and long-term life supercapacitors. Well structured single-crystalline α-Fe<inf>2</inf>O<inf>3</inf> nanowires uniquely served as cores that support redox active high surface area Ni(OH)<inf>2</inf> shells and also contribute to specific capacitance as a conventional pseudocapacitive metal oxide. The Ni(OH)<inf>2</inf>@α-Fe<inf>2</inf>O<inf>3</inf> hybrid composites exhibited excellent rate capability with specific energy of 22.8Wh/kg and specific power of 16.4kW/kg at a current density of 54.6A/g, and excellent long-term cycling stability (keep over 85.7% of the initial specific capacitance after 5000 cycles). These results suggest that such hybrid composite architectures are very promising for the next generation of high-performance supercapacitors. © 2013 Elsevier Ltd.