Effect of nano-MgO on thermal and mechanical properties of aluminate cement composite thermal energy storage materials

Thermal and mechanical properties of high temperature aluminate cementitious thermal energy storage materials enriched with nano-MgO (NM) are investigated. According to the development of thermal storage materials and their application environment requirement in solar thermal power, the specimens were subjected to heating at 105, 350, and 900 °C. It was observed that the addition of NM provided a great improvement on the thermal properties of the composite pastes which were heated principally at 350 and 900 °C. When the NM content was 1 wt%, the thermal conductivities are 34.8% and 23.6% higher than that of pure paste at 350 and 900 °C, respectively. Meanwhile, at 2 wt% NM particles loading, the optimum value of volume heat capacity is obtained, which are 19.8% and 40.8% higher than that of pure paste at 350 and 900 °C, respectively. Moreover, compressive strength of the composite paste with 1 wt% NM presents approximately 30.5%, 27.8%, and 23.8% higher than that of pure paste at 105, 350, and 900 °C, respectively. XRD, TG-DSC, SEM, and MIP were used to characterize the phases, mass/heat changes, microstructure and pore distribution of the hardened cement pastes, respectively.