A new, high electrochemical activity and chromium tolerant cathode for solid oxide fuel cells. (7th December 2015)

• Record Type: Journal Article
• Authors: Zhao, Ling; Cheng, Yi; Jiang, San Ping
• Is Part Of: International journal of hydrogen energy. Volume 40:Number 45(2015)
• Page Start: 15622
• Page End: 15631
• Publication Date: 2015-12-07
• Subjects: Solid oxide fuel cells -- Niobium doped cobalt ferrite -- SSBCFN cathode -- Chromium deposition and poisoning -- Chromium tolerance -- Stability; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.09.091
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The commercialization of solid oxide fuel cell (SOFC) technologies requires the development of cathode materials not only with high electrochemical activity and stability but also with excellent tolerance and resistance towards contaminants such as chromium. Here, a new electrode, Sm0.5(1−x) Sr0.5(1−x) Bax Co1−0.3x Fe0.2x Nb0.1x O3−δ (SSBCFN with x = 0.4, 0.5, 0.6) is developed based on the combined composition of Sm0.5 Sr0.5 CoO3−δ (SSC) and Ba(Co0.7 Fe0.2 Nb0.1 )O3−δ (BCFN). SSBCFN with x = 0.5 (SSBCFN5) shows a high electronic conductivity of 128–221 S cm −1 in the temperature range of 500–900 °C, an essential requirement of SOFCs electrode materials and low electrode polarization resistance of 0.53 Ωcm 2 at 600 °C, significantly lower than 1.79 Ωcm 2 for the reaction on SSC and 0.64 Ωcm 2 on BCFN. SSBCFN5 shows cubic perovskite structure with a high oxygen non-stoichiometry, δ = 0.514 ± 0.027, based on chemical titration method. Compared to SSC and BCFN electrodes, SSBCFN5 shows better electrochemical activity for the oxygen reduction reaction and most importantly, it exhibits excellent stability and resistance toward chromium deposition and poisoning under SOFC operation conditions from 700 to 900 °C. The results indicate that SSBCFN5 is a promising potential cathode of SOFCs with high activity, stability and high tolerance towards contamination by Cr. Highlights: Niobium doped strontium barium cobalt ferrite (SSBCFN) based electrodes are developed for SOFCs. SSBCFN with barium content of 0.5 shows the highest activity and conductivity. SSBCFN has high activity for oxygen reduction reaction. SSBCFN shows excellent tolerance towards Cr contaminants under SOFC operating mode.