Anode microstructural change upon long-term operation for the cathode-supported tubular-type SOFC

Cathode-supported tubular-type cells fabricated by TOTO Ltd. degraded gradually during long-term operation, and a dissection analysis of cells revealed a microstructural change in the anode. In this study, then, the direct observation of the degraded anode was conducted to clarify the influence of this structural change on the performance by using a dual-beam focused ion beam–scanning electron microscopy (FIB–SEM). The microstructural parameters of Ni–(Sc2O3)0.10(CeO2)0.01(ZrO2)0.89 cermet anode were quantitatively evaluated. The significant reduction in triple phase boundary (TPB) length was confirmed, accompanied with the migration and sintering of nickel particles especially in the vicinity of anode/electrolyte interface.