RuO²-based dense electrodes for ESB electrolyte IT-SOFCs

In this work, we evaluated the performance of dense electrodes based on Ru oxides for Er₂O₃ stabilized Bi₂O₃ (ESB) electrolyte. To fabricate symmetric cells, RuO₂ thick films were deposited by screen printing on the parallel surface of dense ESB electrolyte pellets. A very dense layer of Er/Bi ruthenate (EBR) was formed at the interface by in situ solid state reaction between the dense pellet (ESB) and the deposited RuO₂. The reaction led to the formation at the electrode/electrolyte interface of a layer with pyrochlore structure. The electrochemical performance of the EBR/ESB/EBR symmetric cell was investigated using electrochemical impedance spectroscopy (EIS) measurements in air. The dense morphology of the electrodes allowed quantification of the triple phase boundary (TPB) length and its effect on the area specific resistance (ASR).