Facile and controllable synthesis of solid Co3V2O8 micro-pencils as a highly efficient anode for Li-ion batteries

Abstract

Mixed metal vanadate oxides are promising superior anode materials for lithium ion batteries due to their high specific capacities, improved cycling performance and excellent rate properties. In this work, we demonstrate a facile and controllable synthesis of solid Co₃V₂O₈ micro-particles with different morphologies through a hydrothermal method. By controlling the reaction time, either Co₃V₂O₈ micro-plates or micro-pencils could be fabricated. Characterization via X-ray diffraction (XRD) and transmission electron microscopy (TEM) demonstrated the pure phase and solid morphology of the Co₃V₂O₈ micro-pencils. Scanning electron microscopy (SEM) images of the products obtained at different stages clearly revealed the formation process of the Co₃V₂O₈ micro-pencils. Electrochemical measurements of the Co₃V₂O₈ micro-pencils showed an excellent lithium storage capacity (1137 mA h g⁻¹ at 200 mA g⁻¹), good cycling retention (∼670 mA h g⁻¹ after 330 cycles), desirable coulombic efficiency (∼100% for 350 cycles) and notable rate capability (300 mA h g⁻¹ at 2000 mA g⁻¹). The improved electrochemical performances of the solid Co₃V₂O₈ micro-pencils indicate their great potential as high-performance anode materials for lithium ion batteries.