Cathode Properties of Sm{sub}xSr{sub}(1-x)Co,Fe,Ni)O{sub}(3-δ) Sm{sub}0.2Ce{sub}0.8O{sub}1.9 Composite Material for Intermediate Temperature-Operating Solid Oxide Fuel Cell

摘要

Perovskite-structured cathode material containing samarium (Sm) has been recognized as a promising electrode material due to its high electrocatalytic property for intermediate temperature-operating solid oxide fuel cell (IT-SOFC). This research investigated the optimized composition of' Sm{sub}xSr{sub}(1-x)(Co,Fe,Ni)O{sub}(3-δ)/Sm{sub}0.2Ce{sub}0.8O{sub}1.9 on the Sm{sub}0.2Ce{sub}0.8O{sub}1.9 electrolyte and the possible use of an optimized composite material for the IT-SOFC system. The electrochemical and thermal properties of Sm{sub}xSr{sub}(1-x)(Co,Fe,Ni)O{sub}(3-δ) and its composite material with the Sm{sub}0.2Ce{sub}0.8O{sub}1.9 electrolyte were investigated in terms of area specific resistance (ASR) and thermal expansion coefficient at various temperature conditions. Durability of the selected materials was verified by thermal cycling and long-term degradation tests. Sm{sub}0.5Sr{sub}0.5CoO{sub}(3-δ) and the Sm{sub}0.5Sr{sub}0.5CoO{sub}(3-δ) Sm{sub}0.2Ce{sub}0.8O{sub}1.9{6:4) composite cathode showed a very low ASR of 0.87 Ωcm{sup}2 and 0.30 Ωcm{sup}2 at 600° C, respectively. The composite type cathode for the Sm{sub}0.5Sr{sub}0.5CoO{sub}(3-δ) material was more attractive due to its thermal expansion compatibility with neighboring cell components.