Improved electrochemical properties of the Li3V2(PO4)3 cathode material synthesized from a V(III) precursor

Abstract

The choice of precursors can significantly influence the properties of synthesized materials. Here, we describe the effect of two different valence states of vanadium precursors, i.e., V(III) and V(IV), on the electrochemical properties of the resulting Li3V2(PO4)3/C composite synthesized through a sol−gel route. To obtain a homogeneous V(III) solution compatible with the aqueous sol−gel synthesis route, we used a facile and straightfoward electrolysis method to reduce V(IV) into V(III) in the oxalate solution. After the sol−gel and sintering processes, the resulting Li3V2(PO4)3/C composite synthesized from V(III) presents higher specific capacity and better cycle performance at different charging/discharging rates, compared with the composite prepared from V(IV). The improved electrochemical performance of the former is likely due to the more straightforward phase formation process for V(III) than V(IV) precursor in the synthesis.