Fabrication and Performance of La, Co-substituted SrTiO_3 as Cathode Materials of Solid Oxide Fuel Cell

摘要

SrTiO_3-based materials have been investigated to be a candidate for anode of solid oxide fuel cell (SOFC) due to good chemical stability and high ionic conductivity in reducing atmosphere. However, the electronic conductivity is relatively low, which might be increased by doping. In this work, La, Co-substituted SrTiO_3 (LSTC) was fabricated and evaluated as cathode of SOFC. Pechini method was successfully used for material synthesis. By doping of La and Co, the conductivity of materials can be increased to more than 1 S/cm at 800°C. LSTC|Gadolinium-doped ceria|LSTC symmetric cells were also fabricated for electrode performance testing. The results showed that the interface resistance of LSTC cathode can be optimized to be 0.02 Ω·cm~2 at 800°C and 0.3 Ω·cm~2 at 600°C, which indicates possible application of LSTC cathode materials for SOFC. Maximum power density of LSTC cathode on button-sized anode-supported SOFC reached 0.360 W/cm~2 at 800°C.