Fatty acid/metal ion composite as thermal energy storage materials

Abstract

The future of renewable energy lies in the efficiency of energy storage technology used for storing energy produced by the renewables. The sporadic nature of solar energy has a demand for energy storage and efficient storage materials and devices. Therefore, energy storage technologies are gaining a wide range of attention from researchers. This paper mainly focuses on the development of fatty acid/metal ion composite by incorporating sodium ions into the lauric acid to enhance its thermophysical properties. Lauric acid is doped with 0.2, 0.5, and 1 wt% of the sodium metal to form a fatty acid/metal ion composite. Fabrication of the composite without any sophisticated methods or materials is the advantage of the present work. DSC, TGA, thermal conductivity, thermal diffusivity, and FTIR characterization have been conducted to understand the thermal and structural properties of the synthesized fatty acid/metal ion composite. Morphology of the composite was studied using scanning electron microscopy imaging to study the porous nature of the composite. Enthalpy of fusion of the composite was found to be ~ 153, ~ 157, and 161 J/g by adding 0.2, 0.5, and 1 wt% of sodium metal into lauric acid, due to which the enthalpy of phase change was found to be enhanced by 5.3, 7.9, and 10.6%, respectively, in comparison with the enthalpy of pure lauric acid. Besides, the composite exhibited a small reduction in melting point with the increase in wt% of sodium metal in the composite. FTIR spectra of the prepared composite showed that there is no reaction taking place between lauric acid and sodium metal, making it a more stable composite. TGA analysis revealed that the decomposition temperature was enhanced by 30% by the addition of sodium metal into lauric acid, making it shaped-stable and suitable for thermal energy storage application.