In situ generation of carbon-doped modified KCl-LiCl high-efficiency thermal storage materials with 3D network structure

Molten salt phase change thermal storage materials are essential in efficient thermal storage for high -temperature concentrated solar power (CSP). Modified KCl-LiCl eutectic molten salt thermal storage materials with stable structure and thermal properties were formed by direct high-temperature carbonization using xylitol as the carbon precursor by the molten salt template method. The molten salt is encapsulated in a carbon matrix with a three-dimensional entangled network structure, and the rich pore structure binds the molten salt to the carbon material. The interconnected network channels provide pathways for heat transfer from the molten salt and improve the heat transfer capability of the modified molten salt. The results showed that the best performance enhancement of the modified molten salt was achieved when the xylitol content was 4%. The thermal conductivity was 2.412 W/m/K, which was improved by 59.8%, and the specific heat was increased from 0.45 J/g/K to 0.75 J/g/K, an increase of 66.7%, and the latent heat of phase change reaches 212.0 J/g, which still possess a high heat storage density. Due to the connection channels of the network structure, the modified molten salt exhibits better stability and leak resistance. In the self-assembled test setup, the modified molten salt still has good radiative heat transfer performance under the concentrated radiative heat flux, and the maximum temperature difference is only 34.4 & DEG;C. Modified molten salts have great potential in high -temperature solar storage systems, providing new ideas for efficiently utilizing solar energy, reducing resource waste, and promoting sustainable development.& COPY; 2023 Elsevier Ltd. All rights reserved.