The absorptivity of endothermic materials serves as a critical index for solar thermal power photothermal conversion systems, and ceramic-based endothermic materials characterized by high absorptivity also exhibit elevated sintering temperatures. In this study, CaF 2 was employed as an additive to investigate its effects on the physical properties and microstructure of the samples, with a particular focus on the mechanism by which CaF 2 reduces the sintering temperature of corundum-based endothermic ceramics. The results showed that the G2 sample (1 wt% CaF 2 ), sintered at 1650 °C, displayed the best physical properties, including 93 % absorptivity, 165.43 MPa bending strength. The sintering temperature of the CaF 2 -doped G-series samples was around 60 °C lower due to liquid-phase calcium hexaaluminate formation from CaF 2 and Al 2 O 3 , which enhanced atomic migration and facilitated ceramic matrix sintering. Additionally, the capillary forces of the liquid-phase calcium hexaaluminate promoted ceramic matrix shrinkage and accelerated corundum-based grain growth through the dissolution-precipitation mechanism, leading to densification. Moreover, the G2 sample exhibited excellent durability, with absorptivity decreasing by only 1.9 % after 100 h at 1000 °C.
Integrated solar thermal conversion and latent heat storage based on phase change materials (PCMs) has emerged as a promising way for improving solar thermal utilization by avoiding redundant energy transport processes. However, the poor solar absorptance and low thermal conductivity of PCMs prohibit achieving high solar thermal energy storage efficiency. Here, bamboo-derived silicon carbide (BSiC) eco-ceramics based phase change composites are proposed to realize efficient, rapid, and compact solar thermal energy storage. BSiC/paraffin demonstrates a high thermal conductivity of 40 W m −1 K −1 at the porosity of 66%, where 96% pores are filled with paraffin and no prominent deterioration is observed after 2500 cycles. By further loading TiN nanoparticles on BSiC skeletons, an ultrahigh solar absorptance of 96.23% is obtained due to exciting broadband plasmonic resonances. Subsequently, the solar-thermal energy storage efficiency achieves as high as 91.1% at 1.62 W cm −2 . The high-performance solar thermal energy storage benefits from continuous thermal conductive channels and excellent solar absorptance of BSiC/PCMs composites. For high temperature applications , BSiC/LiOH–LiF composites are developed and possess high thermal conductivity of 35.0 W m −1 ·K −1 and large latent heat of 309 kJ kg −1 simultaneously, but corrosion problems need to be tackled before long-time utilization. This work paves the way for applying BSiC eco-ceramics in high-performance solar thermal energy conversion and storage.
危险品化学品经营许可证（带存储）