NdBaCu2O5+δ and NdBa0.5Sr0.5Cu2O5+δ layered perovskite oxides as cathode materials for IT-SOFCs. (14th December 2015)

• Record Type: Journal Article
• Authors: Kong, Xin; Liu, Guiyang; Yi, Zhongzhou; Ding, Xifeng
• Is Part Of: International journal of hydrogen energy. Volume 40:Number 46(2015)
• Page Start: 16477
• Page End: 16483
• Publication Date: 2015-12-14
• Subjects: SOFCs -- Cathodes -- Thermal expansion -- Electrochemical performance; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.09.006
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Cobalt-free perovskite oxides NdBaCu2 O5+δ (NBCO) and NdBa0.5 Sr0.5 Cu2 O5+δ (NBSCO) has been investigated as cathode materials in intermediate-temperature solid fuel cells (IT-SOFCs). The crystal structure, thermal expansion, electrical conductivity and electrochemical properties have been characterized by X-ray diffraction (XRD), dilatometer, four-probe dc method, electrochemical impedance spectroscopy (EIS) and cathodic polarization examinations. The average thermal expansion coefficients (TEC) values of NBCO and NBSCO are 13.0 × 10 −6 /°C and 14.5 × 10 −6 /°C, which are more desirable on combining with the electrolytes than cobalt-based cathodes. The partly substitution of Sr on B-site increases the electron hole concentration and improves the conductivity. The polarization resistances values of NBSCO are 0.205 Ωcm 2, 0.200 Ωcm 2 and 0.135 Ωcm 2, whereas the polarization resistances values of NBCO are 8.61 Ωcm 2, 3.18 Ωcm 2 and 0.83 Ωcm 2 at 600 °C, 700 °C and 800 °C, respectively. The improved electrochemical performance of NBSCO should be ascribed to the higher conductivity as well as the improved oxygen adsorption/desorption and oxygen ions diffusion processes. Graphical abstract: Highlights: NBCO and NBSCO as potential cathodes for IT-SOFCs have been investigated. The TEC of NBCO and NBSCO are more compatible with electrolyte than that of cobalt-based cathodes. The Rp of NBSCO are 0.205 Ωcm 2, 0.200 Ωcm 2 and 0.135 Ωcm 2, at 600 °C, 700 °C and 800 °C, respectively.