Synergistic adsorption of aluminate fumarate loaded with SrCl2/LiCl binary salt with high adsorption heat storage performance

AF composite adsorbents loaded with SrCl 2 and LiCl/SrCl 2 binary salts were developed. • Water adsorption kinetics showed composite adsorbents' synergistic effects. • The adsorption capacity of Sr 0.7 Li 0.3 @AF-20 was enhanced by 194% compared with AF. • LiCl incorporation disrupts the hydrated structure of the Sr@AF-Z composite system. The development of novel adsorption energy storage materials with both high energy storage density and fast adsorption kinetics is crucial for the large-scale application of adsorption heat storage technology. In this work, aluminum fumarate (AF) was used as a support, and composite adsorbents loaded with SrCl 2 single salt and LiCl/SrCl 2 binary salts at different ratios were prepared via impregnation. The adsorption thermal storage behavior, synergistic mechanism between components, and the regulation of LiCl doping ratio on the pore structure and hydration system were systematically investigated. The results demonstrate that the introduction of LiCl effectively tailors the pore structure of AF-based composites, optimizes the mixed hydration system of binary salts, and significantly alleviates pore blockage under low humidity that plagues single-salt systems. The thermal storage capacity of the composites first decreases and then increases with rising LiCl content. Among them, Sr 0.7 Li 0.3 @AF-20 exhibits the best overall performance, with a saturated adsorption capacity of 1.03 g/g-186% higher than pristine AF and 80% higher than the optimal SrCl 2 single-salt sample Sr@AF-20-and a thermal storage capacity of 1097.685 kJ/kg. After 10 adsorption/desorption cycles, it retains 85% of its performance, indicating a certain degree of cycling stability. Thus, the simultaneous improvement of adsorption capacity, thermal energy storage density, and cycling stability was achieved by rationally adjusting the binary salt ratio. These findings provide key material references and novel component design strategies for promoting the industrialization of solar adsorption thermal energy storage technology. Download: Download high-res image (198KB) Download: Download full-size image