Numerical and experimental analysis of the effect of pore formers on the processing and properties of solid oxide fuel cell electrode

The fabrication of ceramic components with controlled porosity often requires using pore formers. This paper shows how modeling can help in optimizing pore former quantity and size with respect to sintering behavior and material properties. The case of a mixed ion-electron conductor SOFC cathode is considered. Numerical simulations based on the discrete element method are performed to mimic the sintering of Nd2NiO4 ceramic powders processed with various fractions of pore formers (0-40%) and size ratios (1-5 times the size of ceramic particles). From the results of these simulations, the effect of pore former particle size and amount on sintering densification, conductivity and effective surface area is analyzed. Experiments achieved on a Nd2NiO4 powder with miscellaneous pore formers confirm simulation outcomes as the minor effect of the pore former particle size ratio on the density and the presence of an optimum of oxygen adsorption for 20 vol.%.