Cathode Properties of SmxSr1−x(Co,Fe,Ni)O3−δ/Sm0.2Ce0.8O1.9 Composite Material for Intermediate Temperature-Operating Solid Oxide Fuel Cell

2009 ◽  
Vol 6 (3) ◽  
Author(s):  
Seung-Wook Baek ◽  
Changbo Lee ◽  
Joongmyeon Bae
Keyword(s):  
Composite Material ◽  
Thermal Expansion ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Composite Cathode ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Oxide Fuel ◽  
Cell Components ◽  
Temperature Operating

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 SmxSr1−x(Co,Fe,Ni)O3−δ/Sm0.2Ce0.8O1.9 on the Sm0.2Ce0.8O1.9 electrolyte and the possible use of an optimized composite material for the IT-SOFC system. The electrochemical and thermal properties of SmxSr1−x(Co,Fe,Ni)O3−δ and its composite material with the Sm0.2Ce0.8O1.9 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. Sm0.5Sr0.5CoO3−δ and the Sm0.5Sr0.5CoO3−δ/Sm0.2Ce0.8O1.9(6:4) composite cathode showed a very low ASR of 0.87 Ωcm2 and 0.30 Ωcm2 at 600°C, respectively. The composite type cathode for the Sm0.5Sr0.5CoO3−δ material was more attractive due to its thermal expansion compatibility with neighboring cell components.

Characterization of PSCF3737 for Intermediate Temperature-Operating Solid Oxide Fuel Cell (IT-SOFC)

2008 ◽  
Author(s):  
Kwangjin Park ◽  
Seungwhan Baek ◽  
Joongmyeon Bae
Keyword(s):  
Fuel Cell ◽  
Oxygen Vacancy ◽  
Solid Oxide Fuel Cell ◽  
Vacancy Concentration ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Oxygen Vacancy Concentration ◽  
Oxide Fuel ◽  
X Ray ◽  
Temperature Operating

Pr0.3Sr0.7Co0.3Fe0.7O3−δ (PSCF3737) was prepared and characterized as a cathode material for intermediate temperature-operating solid oxide fuel cell (IT-SOFC). X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS), and electrical property measurement were performed to study cathode performance of the material. XPS and EXAFS results proved that oxygen vacancy concentration was decreased and lattice constants of the perovskite structure material was increased by doping Fe up to 70 mol% at B-site of the crystal structure, which also extended the distance between oxygen and neighbor atom. Thermal expansion coefficient (TEC) of PSCF3737 is smaller than that of Pr0.3Sr0.7CoO3−δ (PSC37) due to lower oxygen vacancy concentration. PSCF3737 showed better cathode performance than PSC37. It might be due good adhesion by a smaller difference of TEC between Gd0.1Ce0.9O2 (CGO91) and electrode. Composite material PSCF3737-CGO91 showed better compatibility of TEC than PSCF3737. However, PSCF3737-CGO91 did not represent higher electrochemical property than PSCF3737 due to a decline of reaction sites by CGO91.

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