Morphology Dependency of Li3V2(PO4)3/C Cathode Material Regarding to Rate Capability and Cycle Life in Lithium-ion Batteries

Abstract

Transition-metal phosphates have been extensively studied as potential electrode materials for lithium-ion batteries. For this application, high rate capability and cycling performance are required. In this work, we present a one-pot solvothermal synthesis process in combination with in situ carbonization for the tailoring of Li3V2(PO4)3/C morphologies with improvements of the electrochemical performance. These include an unstructured cluster, a needle-like microstructure, a flake-like microstructure and a hollowsphere microstructure. We demonstrate a significant impact of the particle morphology with respect to the electrochemical performance. The results obtained include, for instance, needle-like Li3V2(PO4)3/C showing a superior rate capability of about 72% (∼96 mAh g−1) of its theoretical capacity being maintained at 30C, whereas the flake-like Li3V2(PO4)3/C exhibits outstanding cycling performance with a capacity retention of 97.1% (∼112 mAh g−1) of its initial capacity after 1000 cycles at 2C. Our work demonstrates that the morphology of cathode particles defines a highly selective parameter to improve the electrochemical properties. Accordingly, strategies to selectively tailor particle morphology for a given application become feasible.