Super long-life all solid-state asymmetric supercapacitor based on NiO nanosheets and α-Fe2O3 nanorods

Through a facile hydrothermal method at a mild temperature and a calcination process, we report the fabrication about the NiO nanosheets and alpha-Fe2O3 nanorods using nickel foam (NF) and carbon cloth (CC) as substrates. Analysis of data obtained from the electrochemical experiments show that NiO electrode possesses large areal capacitance (1.3 F cm(-2) at 4 mA cm(-2)). Also, alpha-Fe2O3 electrode delivers areal capacitance of 500 mF cm(-2) at current density of 4 mA cm(-2). Therefore, a high-performance all solid-state asymmetric supercapacitor (ASC) based on 3D sheet-like hierarchical NiO and alpha-Fe2O3 nanorods are designed and fabricated. New ASC can be cycled reversibly in a high voltage region ranging from 0 to 1.25 V with high energy densities of 12.4 W h kg(-1) (power is 951 W kg(-1)) based on the total mass of active materials. Furthermore, the obtained data indicate that the fabricated NiO//alpha-Fe2O3 based supercapacitor device has a great cycle performance with 85% capacitance retention under 10,000 cycles. This work may help to open up new areas for fabrication of lightweight and low-cost materials for energy storage systems. (C) 2016 Elsevier B.V. All rights reserved.