Lithium containing metal phosphate  LiFePO₄, LiMnPO₄, Li₃V₂(PO₄)₃ etc. were explored as a thermally stable electrode materials results from bonding of oxygen to phosphorous stabilizes the structure from oxygen evolution contradict to layered transition metal oxides at high charge voltages. Li₂FeP₂O₇ and Li₂MnP₂O₇ were explored for 2-electrons transfer at high voltage region. Lipscombite related family of Fe_1.37(PO₄)(OH) and Fe_1.19(PO₄)(OH)_0.57(H₂O)_0.43 have been studied for lithium batteries by yanning song et al., which shows reversible capacity of 150 and 100 mAh/g respectively, at current density of 0.5 mA/cm². In the Present study, we synthesized crystalline orthorhombic V₄O₃(PO₄)₃phase related to libscombite/lazulite structure family  by solid state reaction method. Reversible Li- insertion studies were performed on this phase in different voltage windows using galvanostatic and cyclic voltammetry unit.

Electrochemical insertion of lithium into V₄O₃(PO₄)₃ versus lithium metal as reference electrode was studied. 5.8 Li ions intercalation/f.u. and 4.2 Li ions de-intercalated/f.u. are obtained for 1st cycle with 3.9 Li ions reversible de-intercalation or intercalation/f.u. (195 mAh/g) up to 20 cycles at C/5 rate in the voltage window of 1 – 4 V.  In the voltage range of 0.5 – 4 V at C/3 rate reveals 9.8 Li ions intercalation/f.u. and 6.8 Li ions de-intercalated/f.u.  Ex-situ diffraction data conducted on discharged and charged electrode material in the voltage range of 1 – 4 and 0.5 – 4 V vs. Li⁺/Li indicates that phase change occurred after interaction of 2.5 lithium ions per formula unit which is corresponding to initial discharge voltage slope plateau obtained at 2.4 V vs. Li⁺/Li. On further interaction and de-interaction of lithium ions solid solution behaviour is observed. The obtained results will be presented in the presentation.