Hydrothermal synthesis and electrochemical properties of FeNbO4 nanospheres

Abstract

Iron niobate (FeNbO4) nanospheres of an orthorhombic structure were synthesized using a hydrothermal (HT) process at 250°C, and were characterized using X-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, and BrunauerEmmettTeller (BET) measurements. The FeNbO4 nanospheres obtained through the HT reaction revealed a uniform size with an average diameter of 510 nm, and a larger specific surface area (82.72m2 g-1) than that of bulk FeNbO4 powder (2.51m2 g-1) prepared by a solid-state reaction. In addition, the electrochemical properties of the FeNbO4 powders versus Li were evaluated using cyclic voltammetry and galvanostatic charge/discharge cycling. Importantly, the FeNbO4 nanospheres delivered a reversible capacity of over 200mAh g-1 after 20 cycles, and provided an enhanced rate capability compared to the bulk material. © 2012 The Ceramic Society of Japan. All rights reserved.