LnBaCo[sub 2]O[sub 5+δ] Oxides as Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells

作者：Jung‐Hyun Kim, Arumugam Manthiram · 发表于：Journal of The Electrochemical Society · 年份：2008 · DOI：10.1149/1.2839028 · 被引用次数：422 · 研究领域：Advancements in Solid Oxide Fuel Cells、Magnetic and transport properties of perovskites and related materials、Electronic and Structural Properties of Oxides

LnBaCo 2 O 5+␦ ͑Ln = Nd, Sm, Gd, and Y͒ oxides with a cation ordered perovskite structure have been investigated as cathode materials for intermediate-temperature solid oxide fuel cells ͑SOFCs͒.The oxygen content 5 + ␦, thermal expansion coefficient ͑TEC͒, and electrical conductivity ͑metallic͒ decrease with decreasing size of the Ln 3+ ions from Ln = La to Y.While the decrease in TEC is due to the decreasing ionicity of the Ln-O bond, the decrease in electrical conductivity is due to the increasing oxide ion vacancies and a bending of the O-Co-O bonds.The power density of single-cell SOFCs fabricated with the LnBaCo 2 O 5+␦ cathodes, La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 2.8 electrolyte, and Ni-Ce 0.9 Gd 0.1 O 1.95 cermet anode decrease with decreasing size of the Ln 3+ ions, partly due to a decreasing electrical conductivity.The LnBaCo 2 O 5+␦ cathodes with an intermediate lanthanide ion such as Sm 3+ offer a trade-off between catalytic activity and TEC.