Investigations on thermal properties of Metal-doped Na2CO3/MgO composites for thermal energy storage

Abstract

The Na₂CO₃/MgO composites doped with metal part icles, such as Cu, Al, Fe, etc. were prepared. Their synthesis, phase composition, chemical compatibility and thermal properties were investigated. The XRD results show that Na₂CO₃ and MgO have good chemical compatibility. The density of the sample can be increased with doping Cu powders. The onset temperature and the melting point of samples increase with doping Al powder, while those properties with doping Cu powder decrease. With the increase of the content of Na₂CO₃ in the sample, the onset temperature and the melt ing point show an increasing trend. But both the latent heat and the thermal conductivity are shown to be decreased in comparison to Na₂CO₃/MgO composites. Since the samples are sintered in air, the metal powders doped in the PCMs can be oxidized inevitably. Based on these results, it can be inferred that the deterioration of the thermal properties have close relations with the oxidation of metal powders.