Performance and Redox-stability of La and Ni Co-doped SrTiO3 Anode of Solid Oxide Fuel Cell

Abstract

Conventional Ni-cermet anodes show problems for the stability due to carbon coking or Ni coarsening etc.. Perovskite oxides are good candidates as an alternative anode that can solve the problems. Electro-catalytic nanoparticles such as Ni, Ru or Pd can be produced in oxide anodes when exposed to reducing atmosphere. The Ni ex-solution in La0.2Sr0.8Ti0.9Ni0.1O3-δ (LSTN) was determined in our previous work. The electrochemical performances of electrolyte (ScSZ)-supported cells with LSTN anode was improved from that with La0.2Sr0.8TiO3 anode at 800oC in both H2 and CH4 fuels. However, the performance is limited due to poor ionic conductivity of LSTN. In this study, we have studied LSTN (La0.2SrxTi0.9Ni0.1O3-δ) anodes with different A-site composition (x=0.7 or 0.8). We have also studied the effects of Gd0.2Ce0.8O2 (GDC) and/or Ni addition in LSTN. In addition, the redox stability of the anodes was compared with conventional Ni-cermet anode. Impedance spectra and power measurement of the cells with the anodes have shown the redox stable and excellent performance of the cells when GDC and Ni were composited with LSTN.