Ternary Alkali Carbonates Effect on Electrochemical Characterization of Nanocomposite Calcium-Doped Ceria Electrolytes (LNK-CDC) for SOFC

Abstract

The entire world is facing a great shortfall in the energy supply due to the high consumption rate of fossil fuel-based energy resources. Solid oxide fuel cells (SOFCs) are the best alternative energy devices, which convert hydrogen fuel directly into electricity. Alkali carbonated calcium-doped ceria electrolytes (LNK-CDC) as (Ce0.8 Ca0.2), (Ce0.7 Ca0.3), and (Ce0.6 Ca0.4) were synthesized by the co-precipitation method. With the addition of alkali carbonate, nanocomposites of ceria are well preserved after sintering at 600–700 °C. The structural and morphological properties were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Crystallite sizes were found in the range of 50–80 nm. The maximum ionic conductivity of LNK-CDC (Ce0.8Ca0.2) was achieved to be 0.14 S/cm at 650 °C for anion vacancy migration by the dense microstructure. The minimum activation energy was determined to be 0.23 eV. The Fourier-transform infrared spectroscopy (FTIR) spectra of the prepared materials show the absorbance of IR and their behavior. The maximum power density of symmetric fuel cells LNK-CDC sandwiched with LNCZ oxide electrodes was recorded as 0.52 W cm−2 at 650 °C in the presence of hydrogen (fuel). It is suggested that coating of the equal molar ratio of ternary alkali metals on ceria doped comparatively enhance the performance of new nanocomposite electrolyte for SOFC and other energy applications.