Abstract
Latent thermal energy storage is a novel technology based on phase change materials (PCMs) for storing and transporting energy. Sodium acetate trihydrate (SAT) has a large latent heat, but its application is severely restricted by supercooling and phase separation. In this study, a high-performance composite PCM (SAT/SiC/EG) containing SAT (as the PCM matrix), silicon carbide nanoparticles (SiC; as a nucleating agent), and expanded graphite (EG; as a supporting material) were synthesized by stirring and ultrasonic dispersion to ameliorate supercooling and phase separation. The maximum supercooling degree of the composite PCM with 2 wt% SiC and 2 wt% EG was 1.1 °C after 200 heat storage and release cycles. Interestingly, the introduction of EG significantly inhibited the phase separation of SAT, and the composite PCM exhibited excellent dispersion stability after 200 cycles. The addition of 2 wt% and 3 wt% EG significantly improved the thermal conductivity of the composite PCM by 1.09- and 1.77-fold, respectively, as compared to that of SAT. Additionally, the prepared composite PCMs exhibited a large latent heat capacity and a good thermal cycling performance, where the melting and freezing enthalpies of SAT/SiC/EG containing 96 wt% SAT, 2 wt% SiC, and 2 wt% EG was 252.1 J/g and 222.1 J/g, respectively. This study demonstrates that the SAT/SiC/EG composite PCMs have extensive application prospects in middle-low temperature solar thermal energy storage. • The composites PCMs were synthesized by stirring and ultrasonic dispersion method. • Silicon carbide can effectively reduce the supercooling of sodium acetate trihydrate. • The addition of expanded graphite improves phase separation and thermal conductivity. • The heat storage and release rate of the composite PCMS was increased. • The composite PCMs still has a large enthalpy of melting/freezing after 200 cycles.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call