Thermophysical properties of LiF–LiCl–Li2CO3 eutectic mixture/multi-walled carbon nanotubes for thermal energy storage

Abstract

Latent heat thermal energy storage based on solid-liquid phase change material has a huge potential in dealing with mismatch between energy demand and supply. LiF–LiCl–Li 2 CO 3 ternary system was screened out for high temperature energy storage material due to its good thermophysical properties. Its eutectic composition ( X LiF = 28.41 mol%, X LiCl = 55.09 mol% and X Li2CO3 = 16.50 mol%) was predicted based on the developed thermodynamic model and verified experimentally. The melting point, phase change latent heat, heat capacity, thernal diffusivity, thermal conductivity and thermal stability of LiF–LiCl–Li 2 CO 3 eutectic mixture were measured. And the influence of the addition of multi-walled carbon nanotubes (MWCNTs) were analyzed. It was found that adding MWCNTs could increase the latent heat, specific heat capacity, thermal diffusivity and thermal conductivity of LiF–LiCl–Li 2 CO 3 eutectic mixture, while didn't significantly change the melting temperature. • An innovation molten salt is successfully designed via computational thermodynamic approach. • Thermophysical properties of the eutectic salt are determined experimentally. • Composite phase change material (CPCM) was prepared and characterized. • Thermal conductivity and heat capacity can be enhanced by doping nanoparticles.