Evaluation of strontium-site-deficient Sr2Fe1.4Co0.1Mo0.5O6−δ-based perovskite oxides as intermediate temperature solid oxide fuel cell cathodes. (15th June 2016)

• Record Type: Journal Article
• Authors: Zhen, Shuying; Sun, Wang; Tang, Guangze; Rooney, David; Sun, Kening; Ma, Xinxin
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 22(2016)
• Page Start: 9538
• Page End: 9546
• Publication Date: 2016-06-15
• Subjects: Solid oxide fuel cell -- Cathode -- Perovskite oxide -- A-site-deficient; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.04.094
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this paper strontium-site-deficient Sr2 Fe1.4 Co0.1 Mo0.5 O6−δ -based perovskite oxides (Sx FCM) were prepared and evaluated as the cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). All samples exhibited a cubic phase structure and the lattice shrinked with increasing the Sr-deficiency as shown in XRD patterns. XPS results determined that the transition elements (Co/Fe/Mo) in Sx FCM oxides were in a mixed valence state, demonstrating the small polaron hopping conductivity mechanism existed. Among the samples, S1.950 FCM presented the lowest coefficient of thermal expansion of 15.62 × 10 −6 K −1, the highest conductivity value of 28 S cm −1 at 500 °C, and the lowest interfacial polarization resistance of 0.093 Ω cm 2 at 800 °C, respectively. Furthermore, an anode-supported single cell with a S1.950 FCM cathode was prepared, demonstrating a maximum power density of 1.16 W cm −2 at 800 °C by using wet H2 (3% H2 O) as the fuel and ambient air as the oxidant. These results indicate that the introduction of Sr-deficiency can dramatically improve the electrochemical performance of Sr2 Fe1.4 Co0.1 Mo0.5 O6−δ, showing great promise as a novel cathode candidate material for IT-SOFCs. Highlights: Strontium-site-deficient Sr2 Fe1.4 Co0.1 Mo0.5 O6−δ oxides are prepared and evaluated. The TEC and electrical conductivity values firstly decrease and then increase. Sr1.950 Fe1.4 Co0.1 Mo0.5 O6−δ shows the lowest ASR value of 0.093 Ω cm 2 at 800 °C. A maximum power density of 1.16 W cm −2 is achieved by single cell with S1.950 FCM cathode at 800 °C.