Gadolinium doped ceria interlayers for Solid Oxide Fuel Cells cathodes: Enhanced reactivity With sintering aids (Li, Cu, Zn), and improved densification by infiltration

JOURNAL OF POWER SOURCES

卷:372

Article

Nicollet, Clement¹  Waxin, Jenny¹  Dupeyron, Thomas¹  Flura, Aurelien¹  Heintz, Jean-Marc¹  Ouweltjes, Jan Pieter²  Piccardo, Paolo³  Rougier, Aline¹  Grenier, Jean-Claude¹  Bassat, Jean-Marc¹ 

[1] Univ Bordeaux, ICMCB, UPR 9048, CNRS, F-33600 Pessac, France

[2] HTceramix SA, Ave Sports 26, Yverdon, Switzerland

[3] Univ Genoa, Dept Chem & Ind Chem, Lab Met & Mat, I-16146 Genoa, Italy

关键词: Ceria;    Cathodes;    Sintering aids;    Solid oxide fuel cells;    Barrier layer;    Infiltration;   

DOI  :  10.1016/j.jpowsour.2017.10.064

来源: Elsevier

【 摘 要 】

This paper reports the study of the densification of 20% Gd doped ceria (Ce0.8Gd0.2O1.9 (GDC)) interlayers in SOFC cathodes through two different routes: the well-known addition of sintering elements, and an innovative densification process by infiltration. First, Li, Cu, and Zn nitrates were added to GDC powders. The effect of these additives on the densification was studied by dilatometry on pellets, and show a large decrease of the sintering temperature from 1330 degrees C (pure GDC), down to 1080 degrees C, 950 degrees C, and 930 degrees C for Zn, Cu, and Li addition, respectively. However, this promising result does not apply to screen-printed layers, which are more porous than pellets and in which the shrinkage is constrained by the substrate. The second approach consists in preparing a pre-sintered GDC layer, which is subsequently infiltrated with Ce and Gd nitrates and sintered at 1250 degrees C to increase its density. Such an approach results in highly dense GDC interlayers. Using La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) as electrode, the influence of the interlayers on the cathode performance was studied. The addition of sintering aids dramatically increases the cell resistances, most likely because the additives increase the reactivity between GDC and either Yttria Stabilized Zirconia (YSZ) or LSCF, thus losing the expected benefit related to the decrease of sintering temperatures. The interlayers prepared by infiltration do not induce additional resistances in the cell, which results in power densities of single cells 40-50% higher than those of cells prepared with commercial GDC interlayers, making this approach a valuable alternative to sintering aids.

【 授权许可】

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