TY - JOUR
T1 - Systematic evaluation of Co-free LnBaFe 2O 5+δ (Ln = Lanthanides or Y) oxides towards the application as cathodes for intermediate-temperature solid oxide fuel cells
AU - Chen, Dengjie
AU - Wang, Fucun
AU - Shi, Huangang
AU - Ran, Ran
AU - Shao, Zongping
PY - 2012/9/1
Y1 - 2012/9/1
N2 - Co-free oxides with a nominal composition of LnBaFe 2O 5+δ, where Ln = La, Pr, Nd, Sm, Gd, and Y, were synthesized and phase structure, oxygen content, electronic conductivity, oxygen desorption, thermal expansion, microstructure and electrochemical performance were systematically investigated. Among the series of materials tested, LaBaFe 2O 5+δ oxide showed the largest electronic conductivity and YBaFe 2O 5+δ oxide had the smallest thermal expansion coefficient (TEC) of 14.6 × 10 -6 K -1 within a temperature range of 200-900 °C. All LnBaFe 2O 5+δ oxides typically possess the TEC values smaller than 20 × 10 -6 K -1. The oxygen content, electronic conductivity and TEC values are highly dependent on the cation size of the Ln 3+ dopant. The lowest electrode polarization resistance in air under open circuit voltage condition was obtained for SmBaFe 2O 5+δ electrode and was approximately 0.043, 0.084, 0.196, 0.506 and 1.348 Ω cm 2 at 800, 750, 700, 650 and 600 °C, respectively. The SmBaFe 2O 5+δ oxide also demonstrated the best performance after a cathodic polarization. A cell with a SmBaFe 2O 5+δ cathode delivered peak power densities of 1026, 748, 462, 276 and 148 mW cm -2 at 800, 750, 700, 650 and 600 °C, respectively. The results suggest that certain LnBaFe 2O 5+δ oxides have sufficient electrochemical performance to be promising candidates for cathodes in intermediate-temperature solid oxide fuel cells.
AB - Co-free oxides with a nominal composition of LnBaFe 2O 5+δ, where Ln = La, Pr, Nd, Sm, Gd, and Y, were synthesized and phase structure, oxygen content, electronic conductivity, oxygen desorption, thermal expansion, microstructure and electrochemical performance were systematically investigated. Among the series of materials tested, LaBaFe 2O 5+δ oxide showed the largest electronic conductivity and YBaFe 2O 5+δ oxide had the smallest thermal expansion coefficient (TEC) of 14.6 × 10 -6 K -1 within a temperature range of 200-900 °C. All LnBaFe 2O 5+δ oxides typically possess the TEC values smaller than 20 × 10 -6 K -1. The oxygen content, electronic conductivity and TEC values are highly dependent on the cation size of the Ln 3+ dopant. The lowest electrode polarization resistance in air under open circuit voltage condition was obtained for SmBaFe 2O 5+δ electrode and was approximately 0.043, 0.084, 0.196, 0.506 and 1.348 Ω cm 2 at 800, 750, 700, 650 and 600 °C, respectively. The SmBaFe 2O 5+δ oxide also demonstrated the best performance after a cathodic polarization. A cell with a SmBaFe 2O 5+δ cathode delivered peak power densities of 1026, 748, 462, 276 and 148 mW cm -2 at 800, 750, 700, 650 and 600 °C, respectively. The results suggest that certain LnBaFe 2O 5+δ oxides have sufficient electrochemical performance to be promising candidates for cathodes in intermediate-temperature solid oxide fuel cells.
KW - Cobalt-free
KW - Layered perovskite
KW - LnBaFe O cathodes
KW - Solid oxide fuel cells
UR - http://www.scopus.com/inward/record.url?scp=84864278813&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2012.06.073
DO - 10.1016/j.electacta.2012.06.073
M3 - 文章
AN - SCOPUS:84864278813
SN - 0013-4686
VL - 78
SP - 466
EP - 474
JO - Electrochimica Acta
JF - Electrochimica Acta
ER -