Screening of electrode materials and cell concepts for composite ceria + salt electrolytes

Summary The optimization of the performance of electrodes (oxide‐based) for composite electrolytes (Ce 0.9 Gd 0.1 O 1.95  + (Li 0.52 Na 0.48 ) 2 CO 3 ) is addressed in this work acting mostly on the electrode chemical nature (eg, LaCoO 3 , Li 0.43 NiO 2 , or LiNiO 2 ), thickness (single and multiple screen‐printed layers), and cell layer concept (with/without barrier layers between electrode and electrolyte). The cell performance and stability were analyzed by electrochemical impedance spectroscopy, X‐ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. LaCoO 3 electrodes deposited on the electrolyte using an intermediate barrier layer showed a promising area specific resistance of 0.22 Ω.cm 2 at 600°C. This optimized cell processing route was adopted as reference to study the endurance performance of distinct electrode materials up to 100 hours in air, at 550°C, where lithiated NiO showed the best stability.