ABSTRACT

The heat capacity of olivine-type lithium iron phosphate (LiFePO4 LFP) has been measured covering a temperature range from (2 to 773) K. Three different calorimeters were used. The Physical Property Measurement System (PPMS) from Quantum Design was applied in the range between T = (2 and 300) K, a Micro-DSC II from Setaram within the range between T = (283 and 353) K and data between T = (278 and 773) K were measured by means of a Sensys DSC (Setaram) using the Cp-by-step method. Experimental data are given with an error of (1 to 2)% above T = 20 K and up to 8% below 20 K. The data were subdivided into appropriate temperature intervals and fitted using common heat capacity functions. The low temperature results permit the calculation of standard entropies and temperature coefficients of electronic, lattice, as well as magnetic (antiferromagnetic transition at T = 49.2 K) contributions to the heat capacity. The obtained experimental values were compared to results of a recently published first principles phonon study (DFT) and to few available experimental data from the literature.

Compounds

#	Formula	Name
1	FeLiO4P	iron(II) lithium phosphate

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	Triple point temperature, K ; Crystal 2			Crystal 2 Crystal 1 Gas	Relaxation calorimeter	1
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal 2	Temperature, K; Crystal 2	Pressure, kPa; Crystal 2	Crystal 2	relaxation calorimetry	96
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal 1	Temperature, K; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1	relaxation calorimetry	99
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal 1	Temperature, K; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1	Large sample (1 g) DSC	4
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal 1	Temperature, K; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1	Small sample (50 mg) DSC	50
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal 2	Temperature, K; Crystal 2	Pressure, kPa; Crystal 2	Crystal 2	relaxation calorimetry	15
POMD	1	Molar entropy, J/K/mol ; Crystal 2	Temperature, K; Crystal 2	Pressure, kPa; Crystal 2	Crystal 2	relaxation calorimetry	15
POMD	1	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Crystal 2	Temperature, K; Crystal 2	Pressure, kPa; Crystal 2	Crystal 2	relaxation calorimetry	15
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal 1	Temperature, K; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1	combination of DSC and relaxation calorimetry	57
POMD	1	Molar entropy, J/K/mol ; Crystal 1	Temperature, K; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1	combination of DSC and relaxation calorimetry	57
POMD	1	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Crystal 1	Temperature, K; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1	combination of DSC and relaxation calorimetry	57

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Heat capacity (Cp) and entropy of olivine-type LiFePO4 in the temperature range (2 to 773) K

Loos, S.[Stefan], Gruner, D.[Daniel], Abdel-Hafiez, M.[Mahmoud], Seidel, J.[Jurgen], Huttl, R.[Regina], Wolter, A. U. B.[Anja U. B.], Bohmhammel, K.[Klaus], Mertens, F.[Florian]

ABSTRACT