Stabilizing Nanostructured Solid Oxide Fuel Cell Cathode with Atomic Layer Deposition

• Published in: Nano letters Vol. 13; no. 9; pp. 4340 - 4345
• Main Authors: Gong, Yunhui, Palacio, Diego, Song, Xueyan, Patel, Rajankumar L, Liang, Xinhua, Zhao, Xuan, Goodenough, John B, Huang, Kevin
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 11.09.2013
• Subjects: Cathodes; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition; Electrodes; Exact sciences and technology; Ions - chemistry; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanostructures - chemistry; Oxides - chemistry; Oxygen - chemistry; Physics; Reduction; Retarding; Solid oxide fuel cells; Surface chemistry; Surface Properties; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Temperature; Zirconium - chemistry; Zirconium dioxide; degradation; atomic layer deposition; cathode; Solid oxide fuel cell; Thin films; Nanoparticles; Nanometer scale; Confinement; Atomic layer method; Solid oxide fuel cells; Surface segregation; Growth mechanism; Crystal growth from vapors; Nanostructures; Porosity; Nanostructured materials
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl402138w

We demonstrate that the highly active but unstable nanostructured intermediate-temperature solid oxide fuel cell cathode, La0.6Sr0.4CoO3‑δ (LSCo), can retain its high oxygen reduction reaction (ORR) activity with exceptional stability for 4000 h at 700 °C by overcoating its surfaces with a conformal layer of nanoscale ZrO2 films through atomic layer deposition (ALD). The benefits from the presence of the nanoscale ALD-ZrO2 overcoats are remarkable: a factor of 19 and 18 reduction in polarization area-specific resistance and degradation rate over the pristine sample, respectively. The unique multifunctionality of the ALD-derived nanoscaled ZrO2 overcoats, that is, possessing porosity for O2 access to LSCo, conducting both electrons and oxide-ions, confining thermal growth of LSCo nanoparticles, and suppressing surface Sr-segregation is deemed the key enabler for the observed stable and active nanostructured cathode.