Premium
Durability and Performance of High Performance Infiltration Cathodes
Author(s) -
Samson A. J.,
Søgaard M.,
Hjalmarsson P.,
Hjelm J.,
Bonanos N.,
Foghmoes S. P. V.,
Ramos T.
Publication year - 2013
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.201200183
Subject(s) - cathode , materials science , durability , oxide , solid oxide fuel cell , infiltration (hvac) , electrochemistry , porosity , fuel cells , polarization (electrochemistry) , chemical engineering , degradation (telecommunications) , analytical chemistry (journal) , percolation (cognitive psychology) , composite material , electrode , chemistry , anode , metallurgy , chromatography , neuroscience , biology , engineering , telecommunications , computer science
The performance and durability of solid oxide fuel cell (SOFC) cathodes consisting of a porous Ce 0.9 Gd 0.1 O 1.95 (CGO) infiltrated with nitrates corresponding to the nominal compositions La 0.6 Sr 0.4 Co 1.05 O 3–δ (LSC), LaCoO 3–δ (LC), and Co 3 O 4 are discussed. At 600 °C, the polarization resistance, R p , varied as: LSC (0.062 Ω cm 2 ) < LC (0.079 Ω cm 2 ) < Co 3 O 4 (0.27 Ω cm 2 ). High temperature X‐ray diffraction revealed a number of different phases in LSC and LC. The electrochemical performance of the LSC‐infiltrated CGO cathode was found to depend on the infiltrate firing temperature and is suggested to originate from a complex interplay between the formation, percolation, and surface area of electronically conducting and catalytically active phases. Simplified models that predict the R p of LSC‐infiltrated CGO were applied and showed that the performance is not only characterized by the nanoscale size of the infiltrate but also from a better surface exchange property. A 450 h test of an LSC‐infiltrated CGO cathode showed an R p with final degradation rate of only 11 mΩ cm 2 kh –1 . An SOFC with an LSC‐infiltrated CGO cathode tested for 1,500 h at 700 °C and 0.5 A cm –2 (60% fuel, 20% air utilization) revealed no measurable degradation.