Electrical and electrochemical characterization of Li 2O:P 2O 5:Nb 2O 5-based solid electrolytes

Abstract

An extended glass forming region has been identified in the Li 2O:P 2O 5:Nb 2O 5 system. Temperature and composition dependence of conductivity have been measured. A high ionic conductivity value ≅2 × 10 −6 Ω −1 cm −1 at room temperature has been found for the composition 60Li 2O:30P 2O 5:10Nb 2O 5. Conductivity enhancement observed in this ternary system is discussed with reference to glass transition temperature, decoupling index and structural aspects. AC conductivity analysis and dielectric response of the highest conducting composition are described and compared with similar glasses. With the addition of LiF to this glass a conductivity value of 7 × 10 −4 Ω −1 cm −1 at 150° C is observed. The composition is 0.1LiF: 0.9(0.6Li 2O:0.3P 2O 5:0.1Nb 2O 5). A decomposition potential of 2.7 V has been determined for this electrolyte. The energy density for the cell Li/electrolyte/(TiS 2 + 30% electrolyte) has been found to be 108 W-h/kg.