Cr-poisoning of a LaNi0.6Fe0.4O3 cathode under current load

Stodolny, M.K. and Boukamp, B.A. and Blank, D.H.A. and Berkel van, F.P.F. (2012) Cr-poisoning of a LaNi0.6Fe0.4O3 cathode under current load. Journal of power sources, 209 . 120 - 129. ISSN 0378-7753

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Abstract:	This study demonstrates the significant impact of Cr-poisoning on the performance of the $LaNi_{0.6}Fe_{0.4}O_3$ (LNF) SOFC cathode under current load. Volatile Cr-species, originating from a porous metallic foam, enter the working electrode and modify both the LNF cathode layer and the $Gd_{0.4}Ce_{0.6}O_{1.8}$ (GDC) barrier layer, causing increasing overpotential and cell impedance. The increase of the ohmic resistance is caused by a decrease of the in-plane electronic conductivity of the LNF layer (due to Cr incorporation and Ni removal from the LNF perovskite lattice) combined with a deterioration of the ionic conductivity of the GDC barrier layer due to reactivity with Cr resulting in formation of a $GdCrO_{3}$ -phase. The increase of the polarisation resistance is caused by a decrease of the electrochemical activity of the LNF surface towards oxygen reduction reaction at the triple phase boundary (TPB) due to Cr-incorporation in the outer shell of the LNF grains. Chemical reaction and electrochemically driven reaction of volatile Cr-species with LNF and GDC contributes to the extrinsic degradation of the LNF cathodes under current load.
Item Type:	Article
Copyright:	© 2012 Elsevier
Faculty:	Science and Technology (TNW)
Research Group:	Inorganic Materials Science (IMS)
Link to this item:	http://purl.utwente.nl/publications/81885
Official URL:	http://dx.doi.org/10.1016/j.jpowsour.2012.02.083
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