Fabrication and Electrochemical Performance of Zn-Doped La0.2Sr0.25Ca0.45TiO3 Infiltrated with Nickel-CGO, Iron, and Cobalt as an Alternative Anode Material for Solid Oxide Fuel Cells

Abstract

In solid oxide fuel cells, doped strontium titinates have been widely studied as anode materials due to their high n-type conductivity. They are used as current conducting backbones as an alternative to nickel-cermets, which suffer degradation due to coking, sulphur poisoning, and low tolerance to redox cycling. In this work, anode backbone materials were synthesized from La0.2Sr0.25Ca0.45TiO3−δ (LSCTA-), modified with 5 wt.% Zn, and infiltrated with nickel (Ni)/ceria gadolinium-doped cerium oxide (CGO), Fe, and Co. The electrodes were further studied for their electrochemical performance using electrochemical impedance spectroscopy (EIS) at open circuit voltage (OCV) in different hydrogen to steam ratios and at various operating temperatures (850–650 °C). Infiltration of electrocatalysts significantly reduced the polarization resistance and among the studied infiltrates, at all operating temperatures, Ni-CGO showed excellent electrode performance. The polarization resistances in 3% and 50% H2O/H2 atmosphere were found to be 0.072 and 0.025 Ω cm2, respectively, at 850 °C, and 0.091 and 0.076 Ω cm2, respectively, at 750 °C, with Ni-CGO. These values are approximately three orders of magnitude smaller than the polarization resistance (25 Ω cm2) of back bone material measured at 750 °C.

Performance and Sulfur Tolerance of a Short Stack with Solid Oxide Cells Using Infiltrated Strontium Titanate Based Anodes

“…However, the electrochemical performance of SrTiO 3 -based anodes is very low without additional catalyst infiltration, as reported by e.g. N. Muzaffar et al [16] who observed a decrease in polarization resistance at 750 • C and 3% H 2 O/H 2 from 25 Ω cm 2 to below 0.1 Ω cm 2 when Ni:CGO was infiltrated.…”

Effective transport properties of porous composites applied to MIEC SOC electrodes

“…In addition, in some studies a metal catalyst is added, in order to enhance the reactivity for fuel oxidation. 8,40,[46][47][48][49][50] As an alternative structural architecture, perovskite-CGO composite backbones are fabricated, with or without additional metal catalyst infiltration. This type is also reported as a promising SOFC anode.…”

Influence of A-site Deficiency and Ni/Co Ratio in B-site on Electrochemical Performance of (La0.25Sr0,25Ca0.45)yTi0.95Ni0.05-xCoxO3- d Anode

“…In order to improve the electrocatalytic activity of these materials, dopants are introduced in B-sites (Ni, Co, Fe, Mn etc.) (22)(23)(24)(25)(26). In addition, LSCTA-possess an oxygen chemical diffusion coefficient of 3.406 × 10 −7 cm 2 s −1 , within one order of magnitude of the oxide-ion conductor 8YSZ, providing the material with impressive ionic conductivity.…”