Evaluation of the Influence of Nickel Addition on LST-CGO Based Solid Oxide Fuel Cell Anodes Performance

摘要

In this paper we present the combined modeling and experimental study of electrochemical hydrogen oxidation at an alternative perovskite based mixed-conducting SOFC anode. Two types of button cells without and with addition of nickel (Ni) were fabricated based on La_(0.1)Sr_(0.9)TiO_(3-α)(LST)-CGO composite anodes and dense YSZ electrolytes. Electrochemical experiments were performed using symmetrical cell configuration in H_2/H_2O fuel mixture systematically varying applied potentials and operating temperatures. The previously developed model, which includes thermal chemistry at each surface, charge-transfer processes and reactive porous media transport, was employed. It was found that in the case of conventional LST based anodes heterogeneous and charge transfer chemistry at LST surface has capacitive behavior and alters the impedance spectra. However, if nickel is added the influence of LST surface chemistry is diminished leading to an improvement of cell performance.