Structural and Thermal Analysis of CaCO₃/ZrO₂ Composites

CaCO₃ 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 CaCO₃/ZrO₂ composites by physical mixing with a magnetic stirrer using CaCO₃ from natural limestone. The mixing was carried out by mechanical stirring with various molar percentages of CaCO₃:ZrO₂ of 100:0, 85:15, 70:30 and 50:50. The phase and structure of the CaCO₃/ZrO₂ 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 CaCO₃ at the crystalline plane of (104) decreased with increasing percentage of ZrO₂. The lattice volume of CaCO₃ also relatively decreases with increasing percentage of ZrO₂. The increase in the percentage of ZrO₂ in the CaCO₃/ZrO₂ composites makes the decomposition temperature also decreases. This is probably due to heat and mass transfer of ZrO₂.