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 electrolyteCe0.7La0.15Ca0.15normalO2-δ
(LCDC) and the bicarbonate nanocomposite electrolyteCe0.7La0.15Ca0.15normalO2-δ
@KHCO3
(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 KHCO3 bicarbonate on the microstructures and ionic conductivities of KHCO3‐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@KHCO3
nanocomposite is transformed into a LCDC@normalKnormalHnormalCnormalO3/normalK2normalCnormalO3
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@normalKnormalHnormalCnormalO3/normalK2normalCnormalO3
nanocomposite electrolyte.