Improved thermal conductivity and stability of Na2SO4⋅10H2O PCMs system by incorporation of Al/C hybrid nanoparticles

Abstract

Low thermal conductivity is a bottleneck for phase change materials (PCMs), which attracts much attention of the researchers. In this paper, a novel addition agent composed of Al nanoparticle and coated C (Al/C hybrid nanoparticles) was developed to improve the thermal conductivity of sodium sulfate decahydrate (Na2SO4⋅10H2O) PCMs. The Al/C hybrid nanoparticles exhibited thorn ball-like structure, in which hydrothermally generated C was well coated on the surface of Al particle to form a spiny spherical outer coating. Adding ~3 wt% Al/C hybrid nanoparticles caused 26.41% increment to the thermal conductivity (at 30 °C) and 5.13% reduction to the solidification latent heat enthalpy, which can be an effective way to improve the thermal conductivity and solidification latent heat enthalpy of the PCMs. Furthermore, the incorporation of Al/C nanoparticles improved the stability of the PCM system.

Keywords

• Phase change materials
• Thermal conductivity
• Inorganic hydrate salt
• Al/C hybrid nanoparticles
• Thermal energy storage