Nanoparticle-modified thermoelectric tetrahedrite as an effective nucleating agent for sodium acetate trihydrate based phase change materials

Abstract

Abstract Sodium acetate trihydrate phase change materials (SAT-PCMs) for thermal energy storage have been studied and applied widely because of their enhanced energy efficiency and environmental friendliness, while their application on energy exchanging requires stable chemical property and great heat storage-release merit. Nanoparticles-modified tetrahedrite (CNAS-NPs) composites show high thermoelectric properties among copper sulfides, and present excellent nucleating performance in SAT-PCMs. As characterized, the NPs were uniformly distributed into the CNAS grains, and a large number of nanopores were appeared in the grain boundaries after SPS treatment. As a heterogeneous nucleation site, NPs were used to reduce the thermal conductivity, but simultaneously maintained a relatively high electrical conductivity. As a result, by adding a small quantity of SiC, a relatively high ZT ∼ 1.0 at 723 K is obtained, which increases by ∼42% in the pure CNAS sample. Finally, the CNAS-NPs regarded as nucleating agents obviously decrease the supercooling degree and improve the heat storage-release cycle property. These SAT-PCMs also possess high latent heat, fine chemical stability and robust nanostructures, which illustrates promising potentials in practical applications.