Journal of Electroanalytical Chemistry, Vol.804, 36-41, 2017
Effect of sulfur addition on the electrochemical performance of lithium-vanadium-phosphate glasses as electrodes for energy storage devices
Glasses of the composition 37.5Li(2)O-25V(2)O(5)-37.5P(2)O(5) mol% containing different sulfur (0, 10, 50, 100 mol%) content were successfully synthesized and investigated as electrodes for electrochemical devices. Both galvanostatic charge/discharge (GCD) and cyclic voltammetry (CV) were performed to study of electrochemical properties. The results showed that glasses containing sulfur (S) exhibited a high performance, such as specific capacitance, energy density and power density, compared with the S-free glass. These properties increased with increasing of S content. The outstanding electrochemical performance of the glasses containing S can be attributed to the partial substitution of oxygen (O) atoms by S atoms. Since the radius of S ion is higher than O ion, this substitution can signiflcanfly enlarge the size of Li-ion transfer pathway. Besides, S ion has better polarization ability than O ion, thus weakens the interaction between Li ions and glass network. Therefore, the addition of S into oxide glasses may be an effective way to improve the performance of electrochemical devices electrodes.
Keywords:Sulfur addition;DSC;Lithium-vanadium-phosphate glasses;Electrode materials;Energy storage devices