engleski

The effect of replacement of Li2O andAg2O with WO3 and MoO3 on the electrical transport mechanism and structure of zinc phosphate glasses

In this study glasses of the composition (30- 0.5x)M2O-(30-0.5x)ZnO-40P2O5-xTMO (0≤x≤60 mol%) (M = Li, Ag ; TMO = WO3, MoO3) have been investigated. Due to containing both alkali and transition metal oxides, the nature of electrical transport in these glasses is ionic-polaronic. Ionic transport depends on the mobility and concentration of Li+ and Ag+, while polaronic transport depends on the concentration of small polarons. Mixed ion-polaron glasses have been thoroughly investigated for potential applications in solid state Li or Ag batteries as cathode materials. The goal of this investigation is to determine how the replacement of Li2O and Ag2O with WO3 and MoO3 in four glass series affects the glass structure and electrical properties. Raman spectroscopy was used for structural investigation, while electrical properties were determined by impedance spectroscopy. The results have shown that glasses with high Ag2O content have much higher electrical conductivity then their Li2O counterparts of the same composition. The addition of WO3 to the glasses in both series of zinc phosphate glasses causes a drop in electrical conductivity until a minimum (at 20 mol% for Li series and 30-40 mol% of Ag series). Further addition of WO3 increases the electrical conductivity for several orders of magnitude. On the other hand, MoO3 series show different results. In the case of Li series the electrical conductivity is nearly constant up to 50 mol% of added MoO3, while in the same compositional range of Ag series the conductivity is almost linearly decreasing. Further addition of MoO3 shows a slight increase of conductivity due to pure polaronic nature of the glass.

Impendance spectroscopy ; Phosphate Glasses ; Electrical properties

nije evidentirano