The heat capacity temperature dependence of the high-potential solid electrolyte Li7La3Zr2O12 was experimentally determined using differential scanning calorimetry. Besides, the heat capacity in the temperature range 298 800 K was calculated according to the additive Neumann-Kopp rule. The experimental and calculated values of heat capacities are close to each other. The correctness of the Neumann-Kopp assumption for zirconates was also confirmed by comparing the available literature for other similar systems. The molar heat capacity of Li7La3Zr2O12 at constant pressure in the temperature range 298 800 K should be calculated as Cp,m = 533.725 + 0.128 T 9.537 106 T 2, where T is absolute temperature. Other thermodynamic characteristics of tetragonal Li7La3Zr2O12 were determined: entropy (Ss 298 = 424.0 J mol 1 K 1), the standard Gibbs free energy of formation (DfG 298 = 6777.3 kJ mol 1), the enthalpy increment from 0 to 298 K (Hs 298-Hs 0 = 72.64 kJ mol 1), the enthalpy of formation at 0 K (DfHs 0 = 7109.7 kJ mol 1). The performed thermodynamic calculations confirm that solid electrolyte Li7La3Zr2O12 is stable against metallic lithium at room temperature.
Compounds
#
Formula
Name
1
La3Li7O12Zr2
lanthanum lithium zirconium oxide (La3Li7Zr2O12)
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.
Type
Compound-#
Property
Variable
Constraint
Phase
Method
#Points
POMD
1
Molar heat capacity at constant pressure, J/K/mol ; Crystal