Effect of Graded Porous Structure on Ni-YSZ Anode Performance

SOFC anode requires long three phase boundaries (TPBs) and appropriate gas diffusion passes for the fast transport of both fuel and exhaust gases, but the area where gas diffusion passes are especially required would be different from the area suitable for electrochemical reaction in the anode. Then gradient porous structures of SOFC anodes have been proposed to fulfill the anodic functions in adequate anodic areas. Ni- YSZ anodes with various gradient pore-distributions were then prepared using pore-formers by screen-printing method. The relationship between maximum power densities and the pore size and porosity distributions was investigated to identify an effective gradient porous structure that can improve anode performance. The gradient porous structure improved anodic polarization. Pore structure contains two factors of pore size and porosity but the gradient in pore size was more effective in improving anode performance.