Functionally constructed mineral microspheres for efficient photothermal conversion and thermal energy storage

Energy storage materials show enormous potential for the development of energy-saving buildings. However, high-performance composite phase-change materials (PCMs) usually exhibit complex and low photothermal conversion efficiencies. This significantly hinders their application in the construction field. Herein, we reported an effective strategy to construct attapulgite, expanded perlite, and graphite (AEG) ternary composite mineral microspheres through spray drying. Supporting materials were selected to integrate the unique advantages of the materials and achieve a functional design with synergistic benefits. Paraffin–AEG (P-AEG) composite PCMs with light-to-heat conversion and thermal energy storage functions were fabricated via vacuum impregnation. The prepared P-AEG exhibited an excellent light–thermal conversion capability, with a conversion efficiency as high as 92%. In addition, the thermal energy storage building materials constructed with the P-AEG composite PCMs and concrete (P-AEG-C) exhibited exceptional thermal management abilities. At the peak position in the heating stage and the bottom position in the cooling stage, the temperature of the P-AEG-C was 3.9 °C lower and 7.5 °C higher than that of concrete, respectively. The P-AEG-C exhibited excellent mechanical properties with a compressive strength of 14.8 MPa, and thus, it has enormous potential in light–thermal conversion applications and energy-saving buildings.