Synthesis of Carbon-coated Nanoplate α-Na2MoO4 and its Electrochemical Lithiation Process as Anode Material for Lithium-ion Batteries

The carbon-coated alpha-Na2MoO4 nanoplate sample was fabricated via a facile sol-gel method involving the subsequent annealing under a reducing atmosphere to decompose the organic carbon source. X-ray diffraction with Rietveld refinement, high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) results show that single-phase alpha-Na2MoO4 can be obtained even under the presence of carbon and reducing atmosphere. When evaluated as an anode material for lithium-ion batteries, the carbon-coated alpha-Na2MoO4 nanoplate electrode displays a discharge and recharge capacity of 806mAh g (1) and 409mAh g (1) respectively in the first cycle, while a reversible discharge-charge capacity of 350mAh g (1) can be retained after 30 cycles at 30mAh g (1). A capacity of similar to 320mAh g (1) at 30mAh g (1) can still recover after 50 cycles even following the discharge/charge process with the high current density of 480mAh g (1). Meanwhile, carbon-free and carbon-coated alpha-Na2MoO4 powders fabricated via a solid state reaction were also prepared for comparison. Furthermore, the structure change of alpha-Na2MoO4 and its Li storage mechanism upon lithiation and delithiation process are studied by ex- situ XRD and TEM in below. (C) 2014 Elsevier Ltd. All rights reserved.