Atomic Layer Deposition Functionalized Composite SOFC Cathode La0.6Sr0.4Fe0.8Co0.2O3‑δ -Gd0.2Ce0.8O1.9: Enhanced Long-Term Stability

• Published in: Chemistry of materials Vol. 25; no. 21; pp. 4224 - 4231
• Main Authors: Gong, Yunhui, Patel, Rajankumar L, Liang, Xinhua, Palacio, Diego, Song, Xueyan, Goodenough, John B, Huang, Kevin
• Format: Journal Article
• Language: English
• Published: American Chemical Society 12.11.2013
• Subjects: atomic layer deposition; solid oxide fuel cell; cathode; stability
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm402879r

We report that the long-term stability of a conventional mixed oxide-ion and electron conducting solid oxide fuel cell cathode, La0.6Sr0.4Fe0.8Co0.2O3−δ-Gd0.2Ce0.8O1.9 (LSCF-GDC) composite, can be markedly improved by functionalizing its surfaces with a conformal layer of nanoscale ZrO2 films through atomic layer deposition (ALD). Over a >1100 h testing at 800 °C, the overcoated LSCF-GDC cathode exhibited respective polarization and ohmic area-specific-resistances 3 and 1.5 times lower than the pristine sample, whereas the pristine LSCF-GDC cathode degraded at a rate 4 times faster than the overcoated one. The multifunctionality of porosity, mixed conductivity, and suppressed Sr-enrichment enabled by the nanoscaled ALD-ZrO2 overcoats are attributed to the performance retention observed for the overcoated cathode.