Structural and Thermal Analysis of CaCO<sub>3</sub>/ZrO<sub>2</sub> Composites

CaCO 3 is one of abundant minerals in nature, which is a promising material in thermochemical energy storage (TCES). In this work, we have succeeded in synthesizing CaCO 3 /ZrO 2 composites by physical mixing with a magnetic stirrer using CaCO 3 from natural limestone. The mixing was carried out by mechanical stirring with various molar percentages of CaCO 3 :ZrO 2 of 100:0, 85:15, 70:30 and 50:50. The phase and structure of the CaCO 3 /ZrO 2 composites were characterized by x-ray diffraction (XRD). Thermal properties were characterized by thermogravimetri analyzer. Morphology of the composites was observed by scanning Electron microscopy (SEM) with energy dispersive x-ray (EDX). Based on the XRD results, the peak intensity of CaCO 3 at the crystalline plane of (104) decreased with increasing percentage of ZrO 2 . The lattice volume of CaCO 3 also relatively decreases with increasing percentage of ZrO 2 . The increase in the percentage of ZrO 2 in the CaCO 3 /ZrO 2 composites makes the decomposition temperature also decreases. This is probably due to heat and mass transfer of ZrO 2 .