3D montmorillonite aerogel/SA composite phase change materials with mechanically strong strength and superior thermal energy storage performances

Phase change materials (PCMs), which have the ability of absorbing and releasing thermal energy in phase change process, are one of the most reliable materials for thermal energy storage. In this work, stearic acid (SA) used as PCMs were filled into the three-dimensional interconnected montmorillonite (Mt) aerogel to construct composite PCMs (3D-Mt/SA CPCMs) with good shape stability and high mechanical strength. Owing to the super porosity, the CPCMs can encapsulate a large amount of SA and result in the phase change enthalpy as high as 183 J/g. In addition, due to the surface tension and capillary forces of 3D-Mt aerogels, the SA were confined in the pore structure tightly, leading to excellent structural stability and good cycling performances during continuous solid-to-liquid phase change. Results also showed that the prepared 3D-Mt/SA CPCMs can withstand a weight of 500 g without any deformation, and the loads are as high as 1.01 and 13.81 MPa under 55% and 80% deformation, respectively. With high heat storage capacity, good thermal stability, and excellent mechanical strength, the prepared 3D-Mt/SA CPCMs have great application potential in the field of thermal energy storage.