Preparation and Characterization of a Novel Cement Mortar with Paraffin/Expanded Perlite Composite Phase Change Material for Thermal Energy Storage

To explore the application of phase change energy storage materials in building energy efficiency, this study developed a novel composite energy-storage cement mortar using a paraffin/expanded perlite composite as the phase change material (PCM). Six mortar specimens with different mass fractions of the composite PCM were prepared. The specimens were experimentally characterized for their density, microstructure, mechanical properties, thermal conductivity, specific heat capacity, and heat charge/discharge performance in a real environment. The results indicated that the composite PCM possesses a low-density, porous structure. The incorporation of the composite PCM led to decreases in the thermal conductivity, specific heat capacity, and compressive/flexural strength of the mortar, and the extent of this decrease became more pronounced as the mass fraction of the composite PCM increased. The density of the mortar initially increased and then decreased with the addition of PCM. Testing in a real environment demonstrated a temperature peak delay of 20–40 minutes, indicating its practical effectiveness.