Stable and easily sintered (Pr_0.5Nd_0.5) _0.7Ca_0.3CrO_3-δ/Sm_0.2Ce _0.8O_1.9 composite interconnect materials for IT-solid oxide fuel cells

(Pr_0.5Nd_0.5)_0.7Ca_0.3CrO _3-δ (PNCC) interconnect materials are stable in SOFC operating conditions. To improve the sintering ability and electrical conductivity of PNCC, a composite of PNCC/SDC interconnect materials was synthesized by a sol-gel auto-ignition process. The XRD results indicate that PNCC is chemically stable against reaction with SDC at high temperatures. Additionally, SDC-doped PNCC has enhanced sintering activity and electrical conductivity compared to PNCC alone. For 5 wt.% SDC, the relative density of the sample was 95.8% after sintering at 1400 °C, and the electrical conductivity of the sample reached 59.6 S cm^-1 in air and 4.48 S cm^-1 in H₂ at 650 °C. Both of these values are higher than those of pure PNCC. The average thermal expansion coefficient of the samples is close to that of other components of SOFCs. Our results indicate that PNCC/SDC composites are promising intermediate materials for IT-SOFCs.