Low-carbon and low-cost preparation of non-sintering bauxite-based solid thermal energy storage materials

• Published in: Solar energy 2024-03, Vol.270, p.112295, Article 112295
• Main Authors: Li, X., Liu, K.Q., Hao, B.L., Sun, G.C., Zhang, J.Y., Xu, F.T.
• Format: Article
• Language: English
• Subjects: Low-carbon; Non-sintering; Solid thermal energy storage material; Thermal conductivity; Thermal cycles
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2023.112295

•A non-sintering strategy for preparing solid thermal energy storage materials.•The composite binder ensures the satisfied strength of materials at any temperature.•The material exhibits stable thermal cycling performance (400–1000 °C).•The non-sintering preparation greatly reduces CO2 emissions and production costs. In recent years, the rapid growth of clean energy has driven the rapid development of solid thermal energy storage (STES) technology in China. However, the preparation process of commonly used sintered magnesia bricks have the problems of high carbon emissions (7 t CO2/t brick) and high cost, which limits the large-scale application of STES technology. This paper proposes a non-sintering strategy for preparing bauxite-based STES materials. The results demonstrate that the prepared material exhibits good mechanical strength at both room temperature (>15 MPa) and medium-to-high temperatures (>10 MPa), resistance to high-temperature creep (>1250 °C), acceptable thermal conductivity (2.23 W·m−1·K−1), and stable thermal cycling performance with a flexural strength of at least 10 MPa after 20 thermal cycles (400–1000 °C), which satisfies the demand for high-temperature energy storage. Furthermore, the carbon emissions of the non-sintering material is only 30 % of that of sintered magnesia brick, and the production costs are significantly reduced, making them a promising alternative to current sintered STES bricks.