Origin of cathodic degradation and new phase formation at the La0.9Sr0.1MnO3/YSZ interface |
| |
Authors: | Hee Y Lee Seung M Oh |
| |
Institution: | Department of Chemical Technology, College of Engineering, Seoul National University, Seoul 151–742, South Korea |
| |
Abstract: | New phase formation at the La0.9Sr0.1MnO3/YSZ interface and its effects on the cathodic performances were studied at 900 °C in air. The resistance caused by the interfacial product layer kept increasing with time to reach up to 40% of the total resistance after 500 h. The interfacial product was identified as La2Zr2O7 by XRD measurement. The electrical conductivity of La2Zr2O7 (2.4 × 10?5 S cm?1 at 1000 °C), measured by AC impedance and current interruption methods, was 4 to 7 orders of magnitude smaller than those of La0.9Sr0.1MnO3 electrode or YSZ electrolyte. Either the electronic conductivity or the electrochemical O2 reduction activity of La2Zr2O7 was negligible. Combining these results, a conclusion was made that the cathodic degradation comes mainly from the growth of interfacial product layer and its contribution to the cell resistance increment is ohmic in nature. |
| |
Keywords: | Lanthanum zirconate Cathode degradation in SOFC Ohmic losses AC impedance Current interruption |
本文献已被 ScienceDirect 等数据库收录! |
|