High latent heat phase change materials composites based on MXene/biomass-derived cellulose nanocrystalline aerogel for solar-thermal energy conversion and storage

In this study, novel tetradecylamine/MXene/cellulose nanocrystal composite phase change materials (TDA/MXene/CNC CPCMs) were prepared using a vacuum impregnation method. For the first time, lightweight MXene/CNC composite aerogel was employed as a support material in energy storage, with TDA serving as the phase change material. The latent heat of TDA/MXene/CNC CPCMs reached 221.5 J/g. Furthermore, the density of the MXene/CNC-2 composite aerogel was 0.0614 g/cm3, and its loading rate for TDA was as high as 90.6 wt%. Additionally, the thermal conductivity of TDA/MXene/CNC CPCM-5 was 0.491 W/(m·K), 1.87 times higher than that of pure TDA. The TDA/MXene/CNC CPCMs exhibited exceptional thermal stability up to 120 °C and maintained excellent shape stability at 60 °C. The composites exhibit a superior solar-thermal conversion ability with the conversion efficiency as high as 94.1%, The incorporation of MXene significantly enhances the photothermal conversion capability, providing an important avenue for the high-efficiency utilisation of solar energy.