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

Abstract 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/Fe 2 O 3 /K 3 V 5 O 14 . 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/Fe 2 O 3 /K 3 V 5 O 14 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.