Addition of V2O5 in lithium aluminium oxy-fluorophosphate glass system: A possible glassy cathode?

Glass formation region in ternary LiF‒Al(PO3)3‒V2O5 system was determined by melt quenching technique. Homogeneous glasses were obtained by varying V2O5 between 2‒70 mol%. 80LiF‒20Al(PO3)3 composition was chosen as parent glass. V2O5 was added until stable glasses could be cast. V2O5 was substituted for LiF and/or Al(PO3)3 to test its role as glass modifier and/or glass former in presence of Al(PO3)3. Glasses were characterized using XRD, DSC, ICP-AES, FTIR and Electrical Impedance Spectroscopy. V2O5 played dual role‒ of network modifier at low concentrations and of network former with its progressive additions, changing glass structure from predominantly phosphate to vanadophosphate network. These structural changes correlated with the measured properties. Electrical conductivity increased substantially upon V2O5 addition and changed from being predominantly ionic to mixed conduction, with comparable ionic and electronic contributions for ≥ 35 mol% of V2O5, making it a possible candidate for glassy cathode.