(Invited) Developing Electrodes for Solid Oxide Fuel Cells What I Learned from Anil Virkar about Designing High Performance Electrodes

Abstract

The effects of various microstructural and material properties on the electrode overpotentials of solid oxide fuel cells (SOFC) were investigated. A review of the influence and sensitivity of porosity and pore structure on the effective gas diffusivity and resulting concentration polarization of electrodes is presented. The doping of Ni in the anode support as a means to improve redox cycling and stability was demonstrated. Composite electrode layers nearest to the electrolyte were studied with regard to microstructure and materials selection. In particular, the influence of the ionic conductivity of the electrolyte phase in the composite electrode on the electrode polarization was investigated. A fabrication method was developed that produced an electrolyte skeleton with improved particle-to-particle necking and yet extremely porous, that could subsequently be infiltrated with an electrocatalyst material. Applying and combining the various strategies outlined, highly efficient electrodes were developed and demonstrated for solid oxide fuel cells.