Chromium Poisoning of La 1-x Sr x MnO 3±δ Cathodes and Electrochemical Validation of Chromium Getters in Intermediate Temperature-Solid Oxide Fuel Cells
The effect of chromium poisoning on electrochemical performance degradation has been studied at intermediate temperatures (550-650 degrees C) using La1-xSrxMnO3±δ (LSM) cathode and an electrochemical cell configuration air/LSM//YSZ//Pt/air. A rapid increase in polarization resistance is observed in the presence of gaseous chromium species containing humid air (3% H2O) at both 550 degrees C and 650 degrees C. Cross-sectional elemental mapping and high-resolution transmission electron microscopy of the LSM/YSZ interface show the presence of crystalline Cr2O3 and (Mn,Cr)3O4 phases indicating reduction of gaseous hexavalent-chromium species and deposition of solid reaction products. Subsequent experiments, performed under the above exposure conditions but in the presence of a chromium getter, showed stable polarization resistance. The electrochemical performance of half-cells in Cr-containing humid air atmosphere and in the presence of the chromium getter also remained stable during 100-h tests at 550 and 650 degrees C, respectively. The post-test structural and chemical analysis of the electrode, electrode-electrolyte interface and getter by scanning- transmission electron microscopy, energy dispersive X-ray and Raman spectroscopy showed that the cathode bulk and cathode- electrolyte interface remained free of chromium deposits whereas chromium species deposited near the air inlet region of the porous getter as crystalline SrCrO4.
- Research Organization:
- National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE Office of Fossil Energy (FE)
- Grant/Contract Number:
- FE 0023385; AC36-08GO28308; FE-0023385
- OSTI ID:
- 1562978
- Alternate ID(s):
- OSTI ID: 1566053
- Report Number(s):
- NREL/JA-5K00-74917; /jes/166/13/F990.atom
- Journal Information:
- Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Vol. 166 Journal Issue: 13; ISSN 0013-4651
- Publisher:
- The Electrochemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Development of Chromium and Sulfur Getter for Solid Oxide Fuel Cell (SOFC) System
Chromium Tolerant, Highly Active and Stable Electrocatalytic Internal Surface Coating for Cathode of Commercial SOFCs (Final Report)