Enhancement of La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ Durability and Surface Electro-catalytic Activity by La_0.85Sr_0.15MnO_3-δ Investigated using a New Test Electrode Platform

Journal Article · Wed May 04 00:00:00 EDT 2011 · Energy & Environmental Science

DOI:https://doi.org/10.1039/c1ee01188j· OSTI ID:1065090

Lynch, Matthew ^[1]; Yang, Lei ^[1]; Qin, Wentao ^[1]; Choi, Jongjin ^[1]; Liu, Mingfei ^[1]; Blinn, Kevin ^[1]; Liu, Meilin ^[1]

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1. Georgia Inst. of Technology, Atlanta, GA (United States)

A carefully designed test cell platform with a new electrode structure is utilized to determine the intrinsic surface catalytic properties of an electrode. With this design, the electrocatalytic activity and stability of an La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) cathode is enhanced by a dense thin La_0.85Sr_0.15MnO_3±δ (LSM) coating, suggesting that an efficient electrode architecture has been demonstrated that can make effective use of desirable properties of two different materials: fast ionic and electronic transport in the backbone (LSCF) and facile surface kinetics on the thin-film coating (LSM). Theoretical analyses suggest that the enhanced electrocatalytic activity of LSM-coated LSCF is attributed possibly to surface activation under cathodic polarization due to the promotion of oxygen adsorption and/or dissociation by the surface layer and the dramatically increased oxygen vacancy population in the surface film. Further, the observed time-dependent activation over a few hundreds of hours and durability are likely associated with the formation of a favorable hybrid surface phase intermediate between LSM and LSCF. This efficient electrode architecture was successfully applied to the state-of-the-art LSCF-based cathodes by a simple solution infiltration process, achieving reduced interfacial resistance and improved stability under fuel cell operating conditions.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Heterogeneous Functional Materials Center (HeteroFoaM)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: SC0001061
• OSTI ID: 1065090
• Journal Information: Energy & Environmental Science, Vol. 4, Issue 6; Related Information: HeteroFoaM partners with University of South Carolina (lead); University of California, Santa Barbara; University of Connecticut; Georgia Institute of Technology; Princeton University; Rochester Institute of Technology; Savannah River National Laboratory; University of South Carolina; University of Utah
• Publisher: Royal Society of Chemistry
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
catalysis (heterogeneous)
energy storage (including batteries and capacitors)
hydrogen and fuel cells
mechanical behavior
charge transport
membrane
carbon sequestration
materials and chemistry by design
synthesis (novel materials)
synthesis (self-assembly)
synthesis (scalable processing)