Ni infiltrated YSZ anode stabilization by inducing strong metal support interaction between nickel and titania in solid oxide fuel cell under accelerated testing

Abstract

Sintering of Ni particles in Ni infiltrated porous YSZ anodes and decrease in triple phase boundary is the reason for performance loss in SOFC. In the present work, the idea of strong metal support interaction (SMSI) has been used to prevent the sintering of Ni particles by introducing TiO2 as support with Ni catalyst. Electrical conductivity variation of porous YSZ matrix impregnated with Ni and Ni/TiO2 have been investigated. Single button cells (anode supported) with and without TiO2 impregnated Ni–YSZ anode were fabricated and characterized through current–voltage measurement at different loads. It is shown that the conductivity of porous Ni–YSZ anode and the performance of SOFC button cell with the same anode decreased with the increase in temperature and redox cycling at different time intervals. The power density of 12% Ni–YSZ anode was 116 mW/cm2 and it increased to 180 mW/cm2 for 12% Ni–4% TiO2–YSZ based anodes at 800 °C. This increase was interpreted by strong attachment of Ni particles on TiO2 preventing Ni coarsening during prolonged reduction in H2 at 800 °C as observed by SEM. The power density increased with further increase in Ni loading and it reached to 400 mW/cm2 for 16% Ni–4% TiO2–YSZ based anodes. The performance increases with addition of TiO2 support in Ni–YSZ based anodes corroborates with the impedance spectroscopy analyses.