PRELIMINARY INVESTIGATION INTO THE FORMATION OF LiCo0.8M0.2O2-δ (M = Zr, Ca) AS TRIPLE-CONDUCTING OXIDE CATHODES FOR SOLID OXIDE FUEL CELLS

A solid oxide fuel cell (SOFC) is an efficient electrochemical energy conversion device with low emissions. The cathode is one of the principal components of an SOFC, responsible for the reduction reaction. Triple conducting (H+/O2–/e–) cathodes are promising due to their enhanced performance, but existing materials like LiCoO2 (LCO) face stability issues at high temperatures caused by a high cobalt content. Hence, the study focused on synthesizing LiCo0.8M0.2O2-δ (M = dopant) using a glycine-nitrate process and introducing dopants (Zr/Ca) to the cobalt site of LCO to improve stability. Synthesized cathode powders were analyzed using a thermal gravimetric analysis (TGA), X-ray diffractometry (XRD), and field emission scanning electron microscopy/energy dispersive X-ray spectrometry (FESEM/EDX) to assess the thermal decomposition behavior, phase and structure formation, and microstructure, respectively. The XRD analysis confirmed a successful synthesis of homogeneous LiCo0.8M0.2O2-δ cathode powders (M = Zr, Ca) at a calcination temperature of 800 °C. The FESEM/EDX analysis indicated homogenous elemental distribution within the powders, with final experimental molar ratios of LiCo0.79Ca0.21O2-δ and LiCo0.78Zr0.22O2-δ for the Ca- and Zr-doped cathodes, respectively. This successful synthesis paves the way for further research on the stability and performance of these doped cathodes in SOFC applications.