Effect of Ca²⁺ and Zn²⁺ cations substitution on the properties of La_0.85Sr_0.15CrO₃ as SOFC interconnect

The effect of Ca²⁺ and Zn²⁺ cations substitution on the sinterability, thermal expansion and electrical properties of La_0.85Sr_0.15-xCa_xCr_1-yZn_yO₃ as solid oxide fuel cell (SOFC) interconnect materials was investigated. The results showed that the bulk densities of La_0.85Sr_0.15-xCa_xCrO₃ increased with increasing Ca content and a maximum electrical conductivity value of 20.1 S/cm at 800 °C was obtained when x = 0.05. The transition metal Zn substituted in Cr-site further optimized the sinterability and increased the bulk density by 25% when Zn content was up to 0.09. The La_0.85Sr_0.1Ca_0.05Cr_0.91Zn_0.09O₃ sample exhibited an electrical conductivity of 21.5 S/cm at 800 °C and a thermal expansion coefficient (TEC) of 10.3 × 10^-6 K^-1 (20-800 °C), which is compatible with that of 8 mol.%-Y₂O₃-stabilized-ZrO₂ (8YSZ) electrolyte.