Density And Electrical Conductivity Of CILiCsK And AlCl₃-amides Molten Salts

In recent years,intermidate/room temperature molten salts,as electrolytes,found their good application in electrochemistry,thermally regenerative fuel cells,material synthesis,etc.This work studied the density and electrical conductivity of two types of molten salts:LiCl-CsCl-KCl ternary intermidate temperature molten salts(referred to as CILiCsK)and four types of AlCl3-amide room temperature molten salts,which are AlCl3-urea,AlCl3-acetamide,AICl3-propionamide,AIC13-butyramide,respectively.Density and electrical conductivity of melts was determined by Archimedes method and impedance method in a capillary cell,respectively.Meanwhile,the influences of temperature,compositions and additives on the density,specific conductivity and molar conductivity were investigated and discussed.In the case of CILiCsK systems,density and molar volume of ternary mixtures showed a little deviation from addition rule in the investigated composition range.The relationship between electrical conductivity and temperature follows Arrhenius law.The effect of three alkali ions on electrical conductivity follows the order:Li+>K+>Cs+.Electrical conductivity shows obvious deviation from the addition rule with respect to composition change,which was called mixed alkali effect.Moreover,the degree of deviation from ideal situation is larger when the composition of ternary mixtures is closer to eutectic composition.In the case of AICl3-amide room temperature melts,density of each AIC13-amide increases with increasing molar ratio of AlC13-amide.At fixed molar ratio,density of four types of binary systems decreases in the order of AICl3-urea>AICl3-acetamide>AlCl3-propionamide>AlCl3-butyramide,while electrical conductivity decreases in order of AIC13-propionamide>AlCl3-acetamide>AICl3-butyramide>AICl3-urea.There is a maximum value in each curve of electrical conductivity and composition of AlCl3-amide systems.The addition of LiX to the AlCl3-acetamide melt leads to density/conductance increasing in the order of LiBr>LiCl>LiF.