ε-VOPOsub 4: Electrochemical Synthesis and Enhanced Cathode Behavior

was synthesized from the monoclinic and tetragonal forms of by the electrochemical de-intercalation of the protons in both nonaqueous and aqueous electrolytes, as well as by the thermal decomposition of . The so formed readily and reversibly reacts with up to two lithium ions. The from the tetragonal precursor has a reversible capacity exceeding on its higher voltage plateau, and even at a cycling rate has a capacity of comparable to that of the spinel . The electronic conductivity of the is and the lithium chemical diffusion coefficients is in the range of depending on composition. The structure changes little during hydrogen removal and lithium intercalation, and the changes are reversible.