Preparation of a heat storage material from Nano-SiC based composite carbonate with boosted heat storage density for high temperature thermal energy storage

Heat storage materials for high temperature thermal energy storage, e.g., higher than 500 °C, are rather few and their heat storage density (HSD) are insufficient. Therefore, a novel nano-SiC based composite carbonate heat storage material (Nano-SiC CCHSM) was fabricated in this study. The nano-SiC was innovatively applied to improve the HSD of the CCHSM at high temperature. Results show that the addition of nano-SiC significantly improved the HSD of the base material from 542.7 KJ/Kg to as high as 990.7 KJ/Kg. Optimal addition ratio of nano-SiC was 1 % with the sintering temperature of 550 °C. The nano-SiC mainly contributes to improving the sensible HSD of the CCHSM, especially in the liquid sensible HSD. Deep analysis shows that the correlated reaction mechanism is ascribed to the divergent free energy of liquid-phase ions to the nano-SiC, which leads to the heterogeneous nucleation of molten ions and consequently resulting in the high specific heat capacity of the newly formed protruding nanostructures.