Low-temperature synthesis of Cu-doped Li_1.2V₃O₈ as cathode for reversible lithium storage

Abstract

Li_{1 .2}V₃O₈ and Cu-doped Li_1.2V₃O₈ were prepared at a temperature as low as 300 °C by a sol-gel method. The structure, morphology, and electrochemical performance of the as-prepared samples were characterized by means of X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscopy, and the galvanostatic discharge–charge techniques. It is found that the Cu-doped Li_1.2V₃O₈ sample exhibits less capacity loss during repeated cycling than the undoped one. The Cu-doped Li_1.2V₃O₈ sample demonstrates the first discharge capacity of 275.9 mAh/g in the range of 3.8–1.7 V at a current rate of 30 mA/g and remains at a stable discharge capacity of 264 mAh/g within 30 cycles. Furthermore, the possible role that copper plays in enhancing the cycleability of Li_1.2V₃O₈ has also been elucidated.