A-site cation deficiency tuned oxygen transport dynamics of perovskite Pr0.5Ba0.25-xCa0.25CoO3-δ oxide for intermediate temperature solid oxide fuel cells. Issue 12 (15th August 2019)

• Record Type: Journal Article
• Authors: Pang, Shengli; Yang, Gongmei; Su, Yanjing; Xu, Jie; Shen, Xiangqian; Zhu, Meng; Wu, Xiao; Li, Songwei; Chen, Chonglin
• Is Part Of: Ceramics international. Volume 45:Issue 12(2019)
• Page Start: 14602
• Page End: 14607
• Publication Date: 2019-08-15
• Subjects: Solid oxide fuel cells -- Perovskite oxide -- Oxygen transport kinetics -- Oxygen reduction reaction -- Ba-deficiency; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.04.178
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Perovskite oxides with ionic and electronic conductivity are the key cathode materials of solid oxide fuel cells. Most of these materials, however, exhibit large cathodic polarization resistance which is mainly determined by their tardy oxygen transport kinetics. Herein, Pr0.5 Ba0.25-x Ca0.25 CoO3-δ is studied to understand the roles of Ba-deficiency in tuning oxygen transport and electrochemical behaviors in the system. Our findings indicate that Ba-deficiency can significantly accelerate oxygen surface exchange process and bring ∼77% reduction of polarization resistance in this process. It is interesting to note that Ba-deficiency can slightly slow oxygen ion bulk diffusion rate and induce a minor increase of polarization resistance in the corresponding process, which associates with the inhibited oxygen vacancy mobility caused by the interactions between negatively charged Ba vacancy and positively charged oxygen vacancy. These new findings pave a new path for solid oxide fuel cell design and chemical sensor developments. Highlights: Pr0.5 Ba0.245 Ca0.25 CoO3-δ is proposed as an advanced cathode material for IT-SOFCs. The role of Ba-deficiency in tuning the properties of cathode material is revealed. Significantly accelerated oxygen surface exchange kinetics was obtained. A slight decrease in oxygen ion bulk diffusion kinetic was firstly confirmed.