New Nanostructured Vanadium-Containing Cathode Materials for Lithium-Ion Rechargeable Batteries: Mechanochemical Synthesis and Properties
New nanostructured cathode materials based on vanadium - Li <sub>3</sub>V <sub>2</sub>(PO <sub>4</sub>) <sub>3</sub>, LiVPO <sub>4</sub>F and their composites LiVPO <sub>4</sub>F/Li <sub>3</sub>V <sub>2</sub>(PO <sub>4</sub>) <sub>3</sub> were obtained by means of mechanochemically stimulated solid-phase synthesis. The crystal structure and electrochemical properties of the synthesized compounds were studied by means of XPA with refinement according to Rietveld and chronopotentiometry. It was demonstrated that Li <sub>3</sub>V <sub>2</sub>(PO <sub>4</sub>) <sub>3</sub> is stably cycling within the voltage range 3.0-4.3 V, in particular at high current density. Improvement of the cathode characteristics of LiVPO <sub>4</sub>F is promoted by obtaining composite materials LiVPO <sub>4</sub>F/Li <sub>3</sub>V <sub>2</sub>(PO <sub>4</sub>) <sub>3</sub> with nanodomain structure. The possibility to use LiVPO <sub>4</sub>F in symmetric cells with the voltage of 2.4 V is demonstrated.