Effects of Electrolytes on Electrochemical Properties of Cathode Material LaNi0.6Fe0.4O3-d based Fuel Cells

Abstract

Unique electrochemical properties of LaNi0.6Fe0.4O3-δ (LNF) have made it a better choice of cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs) with high power density. To improve electrochemical properties of LNF and analyze the effects of different electrolytes on the performance of LNF-based IT-SOFC, half-cells are fabricated with Ce0.9Gd0.1O2 (GDC) electrolyte or porous GDC backbone/GDC electrolyte. Ag paste is used as a current collector deposited on the cathode material surface. Additionally, LNF and GDC powders are synthesized by sol-gel method leading to the polarization resistance (Rp) and current density of half-cells with two kinds of electrolytes to be measured by a three-electrode method. Experimental results at 550-750 oC show that the polarization resistance (Rp) of LNF/GDC backbone/GDC is 0.376 Ω·cm2 at 750 oC in air, a reduction by 67.02 % compared with that of pure GDC electrolyte at the same temperature. And LNF/GDC backbone/GDC has a higher current density, 0.377 A·cm-2 at 750 oC in air. Systematic analysis suggests that porous GDC backbone improves electrochemical properties of LNF cathode materials.