Electrolytes for sources of electrochemical power

The effect of both the molding pressure and the sintering conditions on a density of solid oxide electrolyte La_0.88Sr_0.12Ga_0.82Mg_0.18O_2.85 is studied. The ablation process of material components from ceramics surface to vaporous state at temperature up from 1573 К is observed. The lattice constant also changes at these conditions. It is assumed that phase transition exists that is responsible to these two phenomena.

An important feature when using low-melting mixtures of halides of s-elements as a refiner of electrolytes for chemical power sources and thermal storage materials in thermal batteries is the amount of volume increase in the melting process which can be calculated by the formula [1]:
ΔV = ((Vк – Vж) / Vк)·100% = (ΔV/Vк)·100%,(1)
where Vк – the volume of a solid substance (or mixture) at the melting temperature; Vж – the volume of liquid at the melting temperature (substance or mixture); ΔV – volume difference in the liquid and solid states of the substance.
Identification of ΔV is necessary because all the halides increase their volume, therefore melting increases the mixture of halides volume. So, when filling chemical power sources and storage heaters by mixtures it is necessary to keep a share of the free volume not only for expansion of the mixture in the solid (including the transition from one crystal structure to another) and liquid state, but also for increasing of the melting compounds volume. But, in the literature [2,3] provides data on the increase volume in the melting is not for everyone halides s-elements (table 1).

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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.

Properties of Dye Solar Cells with quasi solid electrolytes based on PEG have been investigated. The attempts to enhance the electrolyte conductivity was made with Li electrolyte introduction.

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.