Barium vanadium pentoxide-based compounds prepared via a sol-gel process and their evaluation as lithium intercalation materials

The sol-gel process has allowed us to synthesize two new specimens of barium vanadium pentoxide-based compounds: (i) an oxidized orthorhombic Ba-V oxide (referred to as oxidized 'BVO'), whose formula Ba0.18V2O5.15 is close to that of a mixed oxide; (ii) a reduced monoclinic Ba-V oxide (referred to as reduced'BVO'), with formula Ba0.18V2O4.95. Both materials are obtained after specific heat-treatment of the barium exchanged xerogel. The electrochemical features of lithium insertion in both compounds are reported. The oxidized and reduced 'BVO' have different and peculiar electrochemical behaviour, which is discussed in connection with that of the parent orthorhombic V2O5 oxide and the monoclinic Na0.33V2O5 bronze, respectively.