Isostatic pressing of screen printed nickel-gadolinium doped ceria anodes on electrolyte-supported solid oxide fuel cells

Microstructures of porous electrodes have great importance for promoting electrochemical reactions in solid oxide fuel cells (SOFCs). The present paper describes the application of isostatic pressing of screen printed nickel (Ni) gadolinium doped ceria (GDC) composite anode slurry on an electrolyte supported cell (ESC) and quantitatively discusses its influence on the cell electrochemical performance and microstructure. The current-voltage characteristics and electrochemical impedance spectra of the fabricated anodes of the ESC are measured. The microstructure parameters of the anodes are obtained by focused ion beam-scanning electron microscopy (FIB-SEM). The isostatic pressing decreases the porosity of the screen printed anodes, improves the Ni connectivity and increases the active triple phase boundary (TPB) density, but it does not change significantly the total TPB and double phase boundary (DPB) densities. Additionally, pressing enhances the adhesion of the electrode to the electrolyte. These observations are consistent with the improvement of the electrochemical performance of the isostatically pressed anodes.