Effect of A-site Non-stoichiometry on LSCF Cathodes [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 621.3815 Electrical, magnetic, optical, communications, computer engineering; electronics, lighting
• Thông tin xuất bản: Richland, Wash. : Oak Ridge, Tenn. : Pacific Northwest National Laboratory (U.S.) ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2011
• Mô tả vật lý: Size: PDFN
• Bộ sưu tập: Metadata
• ID: 256870
• Chủ đề: 1. 30 direct energy conversion; 2. 36 materials science; 3. Cathodes; 4. Electrodes; 5. Performance; 6. Perovskite; 7. Polarization; 8. Solid oxide fuel cells; 9. Stainless steels; 10. Stoichiometry

Tóm tắt

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.