Communication-Electrochemical Conversion of CuV2O6 into Metallic Cu and LiVO3 with Highly Reversible Lithium Storage

Copper metavanadate (CuV2O6) is tested as a negative electrode for lithium-ion batteries. In the first lithiation, CuV2O6 takes 12 Li+ ions/electrons, during which both Cu2+ and V5+ ions are reduced into their elemental states. In the forthcoming de-lithiation period, only the metallic vanadium is oxidized to form LiVO3, while the metallic copper is idling. From the second cycle, the as-generated LiVO3 is lithiated by a conversion reaction, delivering a reversible capacity of ca. 1000 mA h g(-1). It shows an unusually good cycle retention and Coulombic efficiency owing to the beneficial roles offered by the idling metallic copper. (C) 2017 The Electrochemical Society. All rights reserved.