A model for Ni-particle coarsening and triple phase boundary length prediction in solid oxide fuel cell anode

M.Z. Khan, R-H Song, J-W Lee, S-B Lee, T-H Lim, S-J Park
Korea Institute of Energy Research,
Korea

Keywords: model, Ni coarsening, degradation, anode, solid oxide fuel cell

Summary:

The agglomeration of nickel (Ni) particles in Ni-cermet anode is a significant degradation mechanism for solid oxide fuel cells (SOFCs) during long-term operation. The present study is focused on the development of simple mathematical model to quantify the Ni agglomeration in SOFC anode with operation time. The proposed model is based on Ostwald repining process which accounts Ni particles coarsening and reduction in triple phase boundary (TPB) length per volume with operation time. In addition, the microstructural evolution of Ni in Ni-scandia stabilized zirconia (SSZ) anode functional layer (AFL) was investigated for every 100h operation upto 1000h at 900oC. The modified Ostwald repining model is in excellent agreement with the experimental results and suggest that increment in mean Ni particle radius in AFL was proportional to the around fourth root of operation time (t1/4).