Multilayered SOFC Anode Structure with Electroless Ni-YSZ for Enhancement of Cell Performance

High performance SOFC is fabricated using multilayer anode support with graded porosity. The graded anode fulfills the requirement of proper fuel oxidation at anode, effective electrochemical reaction at anode/electrolyte interface, thermal compatibility among cell components and long term stability. In such multilayer anode, conventional cermet (40 vol % Ni) helps in proper fuel diffusion and catalytic oxidation. Novel electroless anode (28-32 vol % Ni) is employed adjacent to YSZ electrolyte for effective electrochemical activity and thermal compatibility. Because of the presence of unique core (YSZ)-shell (Ni) microstructure, electroless anode is found to extend the anodic electrochemical reaction from electrolyte/anode interface to the bulk. Significant performance enhancement with current density of ~3.3 Acm-2 is observed for single cells fabricated with multilayer anode at 800degC, 0.7V. The multilayer anode is found to reduce the cell degradation from ~11 % (conventional anode) to ~1.6 % /1000 h during long term performance (~2000 h).