твердые электролиты

The phenomenological model of transition «low-conductive phase – electrolytic phase» in crystals with own structural disordering is offered. The application of this model allowed to describe the behavior of thermodynamical characteristics of such crystals in the transition area and to propose an expression for the baric dependence of transition temperature. Analytical expressions for thermocinetical coefficients and for correlation between electric and thermal conductivity of solid electrolyte are obtained.

New potassium solid electrolytes in the systems K 3-2x M x PO 4 (M = Mg, Zn) were synthesized and studied. The introduction of Mg₂₊ and Zn₂₊ cations leads to sharp increasing of K 3 PO 4 conductivity due to potassium vacancies formation and stabilization of high temperature cubic modification of orthophosphate. Maximum conductivity is observed at x ≈ 0.15–0.25 and is equal to (6–8)·10_-2 S·cm_-1 at 400°C, higher than 10_-1 S·cm_-1 at 700°C. The factors influencing on the transport properties of investigated electrolytes are discussed.

New potassium solid electrolytes in the mixed gallate-ferrite systems K_0.85Pb_0.75(Ga_1-xFe_x)O₂ and K_1.85(Ga_1-xFe_x)_1.925V_0.75O₄ were synthesized and studied. In the both systems the monotonic increasing of conductivity with increasing of Fe³⁺ concentration takes place, anomalies as in the early investigated aluminate-ferrite systems does not fixed. Conductivities at the intermediate ranges of «x» have rather high values (> 10^-2 Cm·sm^-1 at 50°C, > 1 Cm·sm^-1 at 70°C), this allowes to optimize the composition of solid electrolytes at the relation of conductivity/stability properties.