Abstract
InBaCo4-xZnxO7 oxides have been synthesized and characterized as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFC). The effect of Zn substitution for Co on the structure, phase stability, thermal expansion, and electrochemical properties of the InBaCo4-xZnxO7 has been investigated. The increase in the Zn content from x = 1 to 1.5 improves the high temperature phase stability at 600 °C and 700 °C for 100 h, and chemical stability against a Gd0.2Ce0.8O1.9 (GDC) electrolyte. Thermal expansion coefficient (TEC) values of the InBaCo4-xZn xO7 (x = 1, 1.5, 2) specimens were determined to be 8.6 × 10-6 to 9.6 × 10-6/°C in the range of 80-900 °C, which provides good thermal expansion compatibility with the standard SOFC electrolyte materials. The InBaCo4-xZn xO7 + GDC (50:50 wt.%) composite cathodes exhibit improved cathode performances compared to those obtained from the simple InBaCo 4-xZnxO7 cathodes due to the extended triple-phase boundary (TPB) and enhanced oxide-ion conductivity through the GDC portion in the composites.
Original language | English |
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Pages (from-to) | 5740-5745 |
Number of pages | 6 |
Journal | Electrochimica Acta |
Volume | 56 |
Issue number | 16 |
DOIs | |
State | Published - Jun 30 2011 |
Funding
This work was sponsored by the Laboratory Directed Research and Development (LDRD) Program of Oak Ridge National Laboratory . A portion of the characterization effort was conducted at both ORNL SHaRE user facility and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, which is sponsored by the Scientific User Facilities Division , Office of Basic Energy Sciences, U.S. Department of Energy. Jung-Hyun Kim and Zhonghe Bi acknowledge the support of the ORISE postdoctoral fellowship. Ashfia Huq acknowledges Spallation Neutron Source for financial support which is supported by the Division of Scientific User Facilities, Office of Basic Energy Sciences, US Department of Energy, under contract DE-AC05-00OR22725 with UT-Battelle, LLC. Financial support for the work done at the University of Texas at Austin by the Welch Foundation grant F-1254 is gratefully acknowledged by Young Nam Kim and Arumugam Manthiram.
Keywords
- Cathode
- Electrochemical properties
- InBaCoZnO
- SOFC
- X-ray diffraction