The advent of thermochemical energy storage (TcES), that is, storage of thermal energy by means of reversible chemical reactions, incites finding pathways of stabilization of thermochemical materials for thermal batteries of the future. Currently, salt hydrates such as LiCl·H₂O, CaCl₂·6H₂O, and SrBr₂·6H₂O are being actively studied for TcES in buildings due to both high energy storage density (1–2.5 GJ/m³) and high storage duration. In this work, we report the core–shell composites “salt in hollow SiO₂ spheres with mesopores” (salt = LiCl·H₂O, CaCl₂·6H₂O, SrBr₂·6H₂O) for domestic TcES. The salt hydrates were encapsulated into submicrometer-sized hollow SiO₂ (HS) capsules as confirmed by transmission electron microscopy (TEM) and N₂ sorption analyses. High sorption/desorption rates due to mesopores of the shells were shown by thermogravimetric analysis (TGA). The sorption equilibrium for salt@HS was reported, and the applicability of the materials for domestic heat batteries was analyzed. As a result of almost the densest packing of salt@HS, the composites were shown to provide a state-of-the-art energy storage density up to 0.86 GJ/m³ on the bed level for the high-temperature lift of 32–47 °C, showing high energy storage capacity. The stability in at least 50 charging/discharging cycles was confirmed by TGA and TEM.

中文翻译：

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将盐水合物核-壳封装到介孔二氧化硅壳中，用于热化学能存储

热化学能量存储（TcES）的出现，即通过可逆化学反应存储热能，激发了寻找稳定未来热电池热化学材料的途径。目前，由于高能量存储密度（1-2.5 GJ / m ³），诸如LiCl·H ₂ O，CaCl ₂ ·6H ₂ O和SrBr ₂ ·6H ₂ O的盐类水合物正在积极研究建筑中的TcES。和高存储期限。在这项工作中，我们报告了核-壳复合材料“在带中孔的空心SiO ₂球中的盐”（盐= LiCl·H ₂ O，CaCl ₂ ·6H ₂ O，SrBr ₂· 6T ₂ O）用于家用TcES。的盐的水合物被封装成亚微米大小的ħ ollow小号IO ₂（HS）胶囊通过透射电子显微镜（TEM）和N作为确认₂吸附分析。通过热重分析（TGA）显示出由于壳的中孔引起的高吸附/解吸速率。报道了盐对HS的吸附平衡，并分析了其在家用热电池中的适用性。由于盐@HS几乎是最密集的堆积，因此显示出该复合材料可提供高达0.86 GJ / m ³的最新能量存储密度在32-47°C的高温升降床水平上显示出高能量存储能力。通过TGA和TEM确认了在至少50个充电/放电循环中的稳定性。