A new chemical route for the synthesis of beta '-LixV2O5 for use as a high performance cathode

Abstract

The high temperature vanadium pentoxide phase, β′-Li xV2O5, was synthesized via a new chemical synthesis involving the evolution of vanadium oxides from the 600 °C heat treatment of the pure LiVS2 in air. By employing this method of synthesis, well-crystallized, rod-shaped β′-LixV 2O5 particles 20-30 μm in length and 3-6 μm in width were obtained. Moreover, the surface of β′-LixV 2O5 particles was found to be coated by an amorphous vanadium oxysulfide film (∼20 nm in thickness). In contrast to a low temperature vanadium pentoxide phase (LixV2O5), the electrochemical intercalation of lithium into the β′-Li xV2O5 was fully reversible where 0.0 < x < 2.0, and it delivered a capacity of 310 mAh g-1 at a current rate of 0.07 C between 1.5 V and 4 V. Good capacity retention of more than 88% was also observed after 50 cycles even at a higher current rate of 2 C.