Vanadium Hexacyanoferrate Derived V-Fe-K Mixed Oxides as Anode Materials for Lithium-Ion Batteries

A new facile solvothermal method has been designed to fabricate a cyanide-metal framework compound of vanadium hexacyanoferrate@rGO, which was then thermally converted into a three-dimensional cubic structure of C/Fe2O3/K3V5O14. In this work, reduced graphene oxide (rGO) provides strength via a rich network structure for particles, enabling changes to the microstructure after calcination. The beneficial features of this nanostructure enhance its structural integrity to limit structural collapse during Li+ insertion/extraction. This has allowed the electrochemical performance of the C/Fe2O3/K3V5O14 electrode to be significantly improved. The electrode shows a reversible capacity of 322.6 mAh g(-1) at a current density of 500 mA g(-1) and high, unprecedented rate capabilities, delivering average capacities of 570, 456, and 343 mAh g(-1) at 100, 200, and 500 mA g(-1), respectively. These results indicate that these newly developed compounds can be promising anode materials for high-performance LIBs.