New Approach to Improve Ionic Conductivity at Low Temperature by the Decomposition of KHCO ₃ in the Nanocomposite Electrolyte @

The current work principally treats the significant aspects of solid electrolytes based on cerium oxide in the absence and presence of potassium bicarbonate. The classic oxide electrolyte (LCDC) and the bicarbonate nanocomposite electrolyte @KHC (LCDC@KHC) are synthesized separately via self‐combustion and co‐precipitation techniques. Structural, thermal, electro‐morphological and electrochemical properties of pure LCDC and nanocomposite material LCDC@KHC are carefully examined. In particular, the influence of the heavily coupling amongst LCDC oxide and KHCO 3 bicarbonate on the microstructures and ionic conductivities of KHCO 3 ‐coated nanocrystalline LCDC is studied by TG/DTA, Raman, FEGSEM and AC impedance spectroscopy. Thermal analyses show that the LCDC@KHC nacomposite is stable at a temperature below 122 °C. Beyond this temperature, the LCDC@KHC nanocomposite is transformed into a LCDC@ nanocomposite. XRD data confirms that the LCDC phase and the various nanocomposite materials LCDC@KHC, sintering at different temperatures, adopt the fluorite structure. Lattice parameters and bond lengths are determined by Rietveld refinement. The ionic conductivity of bicarbonate nanocomposite electrolyte LCDC@KHC is 100 to 1000 times higher than that of the novel classic electrolyte LCDC. The remarkable enhancement of conductivity as a function of temperature rise is correlated to the presence of potassium in two forms: bicarbonate and carbonate in the LCDC@ nanocomposite electrolyte.