Surface oxygen exchange properties of Sr doped La₂NiO_4+δ as SOFC cathode: Thin-film electrical conductivity relaxation investigation

Journal Article · Tue Jun 02 00:00:00 EDT 2015 · ECS Transactions (Online)

DOI:https://doi.org/10.1149/06801.0801ecst· OSTI ID:1267276

Guan, Bo ^[1]; Li, Wenyuan ^[2]; Zhang, Xinxin ^[2]; Liu, Xingbo ^[2]

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1. West Virginia Univ., Morgantown, WV (United States); West Virginia University
2. West Virginia Univ., Morgantown, WV (United States)

La_2-xSr_xNiO_4+δ dense films are prepared by a novel spray-modified pressing method. The surface reaction kinetics is investigated via electrical conductivity relaxation (ECR). The layer thickness, 5~10 μm, is much less than the characteristic length of lanthanum nickelates, resulting in surface-controlled situation and allowing more accurate fitting than the traditional pellets ECR on the surface exchange coefficient (k). k for LNO is 1.6×10^-5 cm/s in 0.2 atm at 700°C. Sr doping impairs the exchange kinetics, and k of Sr40 is about one order of magnitude smaller than undoped one. Interstitial oxygen and Ni oxidation state are suggested the predominant roles in determining surface kinetics. In conclusion, given the properties of the thin-film herein developed by spray-modified pressing is closer to those in practical porous electrode compared to pulsed laser deposited film in terms of preferential orientation and strain, it warrants the use of such a method in a variety of pertinent investigations.

• Research Organization: West Virginia Univ., Morgantown, WV (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: FE0009675
• OSTI ID: 1267276
• Journal Information: ECS Transactions (Online), Journal Name: ECS Transactions (Online) Journal Issue: 1 Vol. 68; ISSN 1938-6737
• Publisher: Electrochemical Society
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
La2-xSrxNiO4+δ
dense films