Brannerite-Type Vanadium-Molybdenum Oxide LiVMoO6 as a Promising Anode Material for Lithium-Ion Batteries with High Capacity and Rate Capability

摘要

Brannerite-type vanadium molybdenum oxide LiVMoO6 is prepared by a facile liquid-phase Method, and its electrochemical properties as anode of lithium:ion batteries are comprehensively studied by means of galvanostatic charge discharge profiles, rate performance, and cyclic voltammetry. In the working voltage between 3.0 and 0.01 V, LiVMoO6 delivers a high reversible capacity of more than 900 mAh g(-1) at the current density of 100 mA g(-1) and a superior rate capability with discharge capacity of ca. 584 and 285 mAh g(-1) under the high current densities of 2 and 5 A g(-1), respectively. Moreover, ex situ X-ray diffraction and X-ray photoelectron spectroscopy are utilized to examine the phase evolution and valence changes during the first lithiated process. A small amount of inserted Li+ induces a decomposition of LiVMoO6 into Li2Mo2O7 and V2O5, which play the host during further lithiated processes. When being discharged to 0.01 V, most V5+ change into V3+/V2+, suggesting intercalation/deintercalation processes, whereas Mo6+ are reduced into a metallic state :On the basis of the conversion reaction. The insights obtained from this study will benefit the design of novel anode materials for lithium-ion batteries.