Li electroactivity of iron (II) tungstate nanorods.

We herein report the first application of a divalent iron tungstate (FeWO(4)) nanostructured material, with a wolframite structure, to a Li-ion battery anode. The FeWO(4) nanospheres and nanorods were synthesized at 180 °C without any surfactants or templates via a facile hydrothermal process by simply adjusting the pH. The resulting nanopowders were characterized using x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), and Brunauer-Emmett-Teller (BET) measurements. Furthermore, we evaluated the Li electroactivity of the FeWO(4) nanorods using cyclic voltammetry and observed that their reversible capacity was over 500 mAh g(-1) after 20 cycles, which proved much higher than that of graphite-based anodes.