Study of magnesium chloride hexahydrate as heat storage material

Heat capacity of MgCl2·6H2O was determined in temperature range from 298.15 to 401.15 K. Polynomial function was used to fit temperature dependence of heat capacity up to 371.15 K and corresponding thermodynamic functions (HT − H298.15, ST − S298.15, GT − G298.15) were calculated. Thermal stability test (50 heating/cooling cycles) of pure MgCl2·6H2O shows supercooling about 37 K, thus some nucleating agents were tested. Addition of SrCO3 (1 wt%) and Sr(OH)2 (0.5 wt%) almost fully suppresses the supercooling while addition of Mg(OH)2 decreases supercooling by 19 K.