Mg(NO3)2·6H2O-LiNO3 eutectic/expanded graphite composite phase change material for thermal energy storage applications

A new eutectic mixture phase change material containing magnesium nitrate hexahydrate and lithium nitrate has been successfully prepared, which can be applied in the field of residential radiator heating due to the suitable phase change temperature and high latent heat. Further, by physical blending magnesium nitrate hexahydrate/lithium nitrate eutectic mixtures and expanded graphite, the new composites were prepared. The crystalline structure, thermal properties, corrosion performance of eutectic phase change materials were systematically measured. The results showed that the best eutectic mixtures had a phase change temperature of 72.35 °C and latent heat of 170.32 kJ/kg, with a little supercooling degree. The thermal conductivity was effectively improved by adding expanded graphite. Meanwhile, corrosion tests suggested aluminum and stainless steel 304 could be the preferred choices as the container. Overall, the prepared eutectic composite materials with superior performances could be a promising candidate for the residential radiator heating field.