In the present investigation Samarium doped barium cerate electrolyte powder of (1-x)Ce0.8Sm0.2O2-δ -xBaCe0.8Sm0.2O3-δ (where x = 0.1 mol fraction) stoichiometry formula is successfully synthesized through wet chemical route. A SDC-BCS nanocomposite electrolyte is premeditated with respect to its thermal, structural, morphological properties and conductivity performance. The crystal structure and microstructure of the SDC-BCS composite is investigated from XRD and SEM analysis. TG analysis reveals that the calcination temperature (900 °C) of the as prepared powder sample. The crystal structure of as prepared SDC-BCS composite powder is identified as cubic perovskite with orthorhombic distortions occurred at 900 °C. From TEM analysis, the particle size is found to be around 32 nm. SEM analysis reveals that the existence of dual phase microstructure in the composite at 1400 °C. The preparation of dense SDC-BCS nanocomposite with the development of dual phase microstructure is achieved for the better ionic conductivity in SDC-BCS nanocomposites for SOFC application.