Data for: A novel multiwalled LiF@GO@SiO2 microcapsule with high phase change temperature

High temperature phase change materials (PCMs)-encapsulated microcapsules with large heat exchange area for addressing specific energy storage have increasing application potentials in many fields. Herein, a novel hybrid multiwalled microcapsule LiF@GO@SiO2 with high phase change temperature was designed and fabricated, which could overcome strong corrosion and volume expansion of lithium fluoride (LiF) during heat storage process. The multiwalled structure of microcapsule contained three layers, consisting of volume expansion buffer layer polydopamine (PDA), anti-corrosion leakage-proof layer (GO) and heat-resist strength layer (SiO2), respectively. Volume expansion buffer layer would be vanished during thermal cycling, and GO as well as SiO2 layers played important roles in protecting molten LiF from leakage. A series of tests including SEM, SEM-EDS, FTIR, XPS, XRD and TGA revealed that three-layer shells were sequentially coated on the surface of core material LiF successfully. Besides, DSC results via quantitatively analyzing, indicated that LiF@GO@SiO2 microcapsules had high phase change temperature of 848 ℃, encapsulation ratio of 82.0% and latent melting heat of 894.5 J/g. In addition, encapsulation ratio of the microcapsule had a minor deflection within 5% after 10 times loops by calculating and comparing corresponding enthalpies, which displayed prepared microcapsule could be used repeatedly in high temperature energy storage. Overall, our results opened new avenues for the utilization of high temperature PCMs and their packaging technique.

为解决特定储能需求而开发的大换热面积高温相变材料（PCMs）包覆微胶囊，在众多领域展现出日益增长的应用潜力。本文设计并制备了一种具有高相变温度的新型多层壁复合微胶囊LiF@GO@SiO₂，可解决氟化锂（LiF）在储能过程中面临的强腐蚀与体积膨胀问题。该微胶囊的多层壁结构包含三层功能层，分别为体积膨胀缓冲层聚多巴胺（PDA）、防腐蚀防泄漏层氧化石墨烯（GO）以及耐热强度层二氧化硅（SiO₂）。其中体积膨胀缓冲层在热循环过程中会逐步降解消失，而GO与SiO₂层可有效保护熔融态LiF不发生泄漏。通过扫描电子显微镜（SEM）、扫描电子显微镜-能谱仪（SEM-EDS）、傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）、X射线衍射（XRD）与热重分析（TGA）等一系列表征测试，证实三层壳层已成功依次包覆于芯材LiF表面。此外，通过定量分析差示扫描量热法（DSC）的测试结果可知，LiF@GO@SiO₂微胶囊的相变温度高达848℃，包覆率为82.0%，熔融潜热可达894.5 J/g。经计算并对比10次热循环后的焓值，该微胶囊的包覆率偏差仅在5%以内，表明所制备的微胶囊可反复应用于高温储能场景。综上，本研究成果为高温相变材料及其封装技术的应用开辟了全新路径。