The high temperature vanadium pentoxide phase, β′-Li x V2O5, 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′-Li x V2O5 particles 20–30μm in length and 3–6μm in width were obtained. Moreover, the surface of β′-Li x V2O5 particles was found to be coated by an amorphous vanadium oxysulfide film (∼20nm in thickness). In contrast to a low temperature vanadium pentoxide phase (Li x V2O5), the electrochemical intercalation of lithium into the β′-Li x V2O5 was fully reversible where 0.0< x <2.0, and it delivered a capacity of 310mAhg−1 at a current rate of 0.07C between 1.5V and 4V. Good capacity retention of more than 88% was also observed after 50 cycles even at a higher current rate of 2C.