Impact of Electrical Conductivity on the Electrochemical Performances of Layered Structure Lithium Trivanadate (LiV_3–xM_xO₈, M= Zn/Co/Fe/Sn/Ti/Zr/Nb/Mo, x = 0.01–0.1) as Cathode Materials for Energy Storage

Pristine trivanadate (LiV₃O₈) and doped lithium trivanadate (LiV_3–xM_xO₈, M = Zn/Co/Fe/Sn/Ti/Zr/Nb/Mo, x = 0.01/0.05/0.1 M) compounds were prepared by a simple reflux method in the presence of the polymer, Pluronic P123, as the chelating agent. For comparison, pristine LiV₃O₈ alone was also prepared in the absence of the chelating agent. The Rietveld-refined X-ray diffraction patterns shows all compounds to exist in the layered monoclinic LiV₃O₈ phase belonging to the space group of P2₁/m. Scanning electron microscopy analysis shows the particles to exhibit layers of submicron-sized particles. The electrochemical performances of the coin cells were compared at a current density of 30 mA/g in the voltage window of 2–4 V. The cells made with compounds LiV_2.99Zr_0.01O₈ and LiV_2.95Sn_0.05O₈ show a high discharge capacity of 245 ± 5 mA h/g, with an excellent stability of 98% at the end of the 50th cycle. The second cycle discharge capacity of 398 mA h/g was obtained for the compound LiV_2.99Fe_0.01O₈, and its capacity retention was found to be 58% after 50 cycles. The electrochemical performances of the cells were correlated with the electrical properties and the changes in the structural parameters of the compounds.