Effect of A-site Non-stoichiometry on LSCF Cathodes

Templeton, Jared W. ; Lu, Zigui ; Stevenson, Jeffry W. ; Hardy, John S.

Pacific Northwest National Laboratory (U.S.)

关键词: Perovskite;    Cathodes;    Electrodes;    36 Materials Science;    30 Direct Energy Conversion;   

DOI  :  10.2172/1036437
RP-ID  :  PNNL-20902
RP-ID  :  AC05-76RL01830
RP-ID  :  1036437

美国|英语

来源: UNT Digital Library

【 摘 要 】

LSCF Cathodes were explored when effected with A-site non-stoichiometry. At 700-800 C, the operating temperatures of intermediate temperature (IT-) SOFCs have enabled the use of stainless steels in the SOFC framework and current collectors, allowing significant reductions in cost. However, the lower operating temperatures of IT-SOFC's also result in significant decreases in power densities of cells with LSM cathodes due to their high activation energies. LSCF is a mixed ionic electronic conducting perovskite that exhibits higher performance than LSM/YSZ composites and shows potential as a replacement cathode. This study investigates the effect of A-site stoichiometry on the performance of LSCF cathodes. Cell tests showed that A-site and Sr-deficient LSCF cathodes consistently outperformed stoichiometric LSCF cathodes, exhibiting up to 10% higher cell power densities. It was also observed that all stoichiometric, A-site, and Sr-deficient LSCF cathodes degraded over time at similar rates. Contributions of ohmic and electrode polarization losses to cell degradation rates were similar regardless of cathode composition.