Superhydrophobic multi-shell hollow microsphere confined phase change materials for solar photothermal conversion and energy storage

The development of efficient solar photothermal conversion and energy storage composite (SPCSC) is of great significance in solving the imbalance between supply and demand of solar energy utilization in time and space. Herein, we prepare multi-shell hollow spheres by selecting glucose as the template and magnesium carbonate trihydrate (MgCO 3 ·3H 2 O) and chloroplatinic acid hexahydrate (H 2 PtCl 6 ·6H 2 O) as raw materials by hydrothermal-calcination method. Octadecylamine (ODA) is loaded into MSHS by vacuum impregnation to prepare SPCSC with excellent comprehensive properties (MSHS@ODA). The multi-layer hollow microspheres provide the micro-nano space structure for ODA, enhance the heat transfer rate of MSHS@ODA, effectively solve the leakage problem, and enable MSHS@ODA to have a fast photothermal response. MSHS@ODA possesses a high light absorption (75.5%), thermal conductivity (0.35 W·m −1 ·K −1 ), and photothermal conversion. The phase change enthalpy can reach 130.7 J·g −1 and maintain a high energy storage density during 100 cyclic phase change tests. Specifically, MSHS@ODA decreases the operating temperature of lithium-ion batteries by 8 °C during discharge, ensuring their stable operation within the optimal temperature range. Based on the above merits, MSHS@ODA may find useful applications in solar thermal storage and effectively managing the thermal conditions of lithium-ion batteries.