La_0.85Sr_0.15Cr_0.9Ni_0.05Pd_0.05O₃ Perovskite Anode for SOFC

Abstract

A Pd doped perovskite La_0.85Sr_0.15Cr_0.9Ni_0.05Pd_0.05O₃ (LSCNP) was investigated as a candidate for a metal-free anode material of solid oxide fuel cell. The deposition and the solid dissolution by reduction and oxidation treatment were observed by FE-SEM and the change of crystal structure was observed by XRD. The performance of anode prepared by mixing LSCNP and Sm doped ceria (SDC) was measured using H₂ and dry CH₄ as fuel. The anode voltage gradually decreased during the power generation, but recovered by oxidation treatment. Electrochemical impedance spectra were measured and the interfacial resistance increased during the power generation, but it decreased by oxidation treatment. The recovery of the performance due to the deposition and solid solution was confirmed. The performance of LSCNP-SDC anode using dry CH₄ as fuel showed a maximum at 5ccm, and the maximum current density was 500 mA cm^–2. From the impedance spectroscopy, it was revealed that when the flow rate was high, the relatively low water vapor pressure diminished the reforming reaction, whereas when the flow rate was low, the insufficient supply of fuel increased the diffusion resistance.