Performance assessment of Pr1−xSrxCo0.8Cu0.2O3−δ perovskite oxides as cathode material for solid oxide fuel cells with Ce0.8Sm0.2O1.9 electrolyte
In this paper, Pr1−xSrxCo0.8Cu0.2O3−δ (x = 0.2, 0.3, 0.4, 0.5, 0.6) cathode material is investigated for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Pr1−xSrxCo0.8Cu0.2O3−δ oxides are prepared by the EDTA-citrate complexing method. XRD results show that there is a structural change from orthorhombic (x = 0.2 and 0.3) to cubic (x = 0.4, 0.5 and 0.6) in Pr1−xSrxCo0.8Cu0.2O3−δ system. The electrical conductivities of all the samples are all higher than 523 S cm−1 between 500 and 800 °C. The semiconductor-to-metal conductivity transition takes place at around x = 0.4. In order to further reduce thermal expansion coefficients (TECs) and improve electrochemical performance of the Pr1−xSrxCo0.8Cu0.2O3−δ cathode, we fabricate Pr0.5Sr0.5Co0.8Cu0.2O3−δ–x wt% Ce0.8Sm0.2O1.9 (PSCC–xSDC, x = 20–60) composite cathodes. In PSCC–xSDC electrode, the TEC and polarization resistance (Rp) both decrease with the addition of SDC. The PSCC–50SDC composite cathode has the lowest Rp. The lowest Rp 0.029 Ω cm2 is obtained at 800 °C for PSCC–50SDC electrode. Subsequently, we fabricate SDC (300 µm thick) electrolyte-supported fuel cell with PSCC–50SDC cathodes. The maximum power densities is 428 mW cm−2 at 800 °C. The present results demonstrate that PSCC–50SDC composite is a promising candidate cathode for IT-SOFCs.
This work was supported by the Natural Science Foundation of China (Nos. 61605059 and 21701047), Program for the development of Science and Technology of Jilin province (Nos. 20180414008GH, 20180519016JH and 20180520191JH), The 13th Five-year Program for Science and Technology of Education Department of Jilin Province (Nos. JJKH20170372KJ and JJKH20180784KJ), Program for the development of Science and Technology of Siping city (No. 2017055), Open Project of Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Nomal University (No. 2016002) and Open Project of the State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (No. RERU2017013).