Synergetic enhancement of mechanical and electrical properties in Ce_0.8Sm_0.1Nd_0.1O_2−δ/La₁₀Si₆O₂₇ composite electrolytes

Abstract

It has been demonstrated that the samarium and neodymium codoped ceria (Ce0.8Sm0.1Nd0.1O2−δ abbreviated SNDC) shows high ionic conductivity at intermediate operating temperature (0.012 S/cm at 500°C. However, the poor mechanical properties limited its applications in solid fuel cells and oxygen sensors. Present research reports an approach to improve the mechanical properties of SNDC by adding another kind of oxide solid electrolyte, the apatite‐type lanthanum silicate (La10Si6O27 abbreviated LSO). The SNDC/LSO composites were prepared by mixing the powders with different proportion, and sintered at 1600°C. Their structure, morphology, mechanical, and electrical properties were characterized. It was found that with the 5wt%‐7wt% LSO addition, both the flexural strength and the fracture toughness were improved. The improvement of flexural strength for the SNDC reached as high as 71%. It is also seen that the ionic conductivity of SNDC was enhanced with the adding of 5wt% LSO. The enhanced mechanical properties and electrical conductivity of SNDC/LSO composites make them a promising candidates for high‐performance SOFCs and oxygen sensors.