0013-4651/2012/159(6)/B661/5/$28.00 © The Electrochemical Society An Efficient SOFC Based on Samaria-Doped Ceria (SDC) Electrolyte

Doped ceria has been widely studied as electrolyte materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). While high peak power densities have been reported, the electronic conductivity of doped ceria under fuel cell operating conditions reduces the open circuit voltage (OCV) and hence energy efficiency, more so with thinner electrolyte membrane at higher operating temperatures. Here we report a new cell structure: a thin SDC electrolyte membrane supported by a composite anode consisting of a mixed-ion conductor BaZr0.1Ce0.7Y0.1Yb0.1O3−δ (BZCYYb) and NiO. The inter-diffusion between BZCYYb and SDC during co-firing results in a thin layer of doped barium cerate and zirconate at the interface, which suppresses the electronic conduction of SDC and enhances the OCV and cell performance. The new cell structure also shows excellent stability when wet hydrogen or methane was used as fuel at 750◦C. ©2012 The Electrochemical Society. [DOI: 10.1149/2.032206jes] All rights reserved. Manuscript submitted January 30, 2012; revised manuscript received February 28, 2012. Published March 23, 2012. Intermediate-temperature solid oxide fuel cells (IT-SOFCs) have attracted worldwide attention because lowering the operating tem-perature (from 1000◦C to 500–800◦C) has potential to considerably widen the selection of less expensive materials to reduce cost while improving the reliability and operational life of SOFC systems.1–4 It i