Corrugated electrode/electrolyte iInterfaces in SOFC : theoretical and experimental development
Résumé
The present work proposes to explore how the presence of a periodic pattern at electrode/electrolyte interfaces of a SOFC could impact the electrochemical performances, from theoretical and experimental points of view. The model results demonstrate that a patterned interfaces along with an electrolyte having a thickness smaller than the dimensions of the pattern, lead to a strong increase of the exchange surface, hence to the exchange currents (up to 64%) with respect to flat interfaces. With the use of laboratory standard ceramic processes, this architecturation was experimented on YSZ-Ni self supported anodes on top of which a thin YSZ electrolyte was deposited. The first electrical tests for such a cell with a non-optimized thickness show an increase of the current density with respect to a cell with flat interfaces, from 130 to 300 mA cm-2 at 0.7 V, that is even higher than anticipated by the modeling.