Efficient optimization of the Li-ion conductivity of borovanadate glass materials for Li-ion batteries

Abstract

The lithium-doped borovanadate glasses of high chemical purity are obtained via the traditional-melt quenching method. The obtained glasses are identified as having an amorphous character by XRD. DSC spectra reveal the glassy nature and good thermal stability of the prepared samples. FTIR spectroscopy reveals the structural groups of these glasses. The incorporation of Li+ ions into the glass modifies the boron coordination so that the boron coordination number changes from BO4 to BO3. The structural conversion of BO4 to BO3 boosts the number of NBOs. The increased number of NBOs indicates borate network depolymerization and a more open network structure, which leads to Li+ ions easily transferring in the glass network. This, in turn, optimizes the ionic conductivity of the present glassy system and can be of order 10−4 S.cm−1 at 300 K. This is the highest value of ionic conductivity reached by the borovanadate glasses at 300 K. Accordingly, borovanadate glasses containing lithium could pave the way for the use of glass materials as electrode material for Li-ion batteries.