A highly efficient and durable air electrode for intermediate-temperature reversible solid oxide cells

• Published in: Applied catalysis. B, Environmental Environmental, 2021-12, Vol.299 (C), p.120631, Article 120631
• Main Authors: Zhang, Weilin, Zhou, Yucun, Liu, Enzuo, Ding, Yong, Luo, Zheyu, Li, Tongtong, Kane, Nicholas, Zhao, Bote, Niu, Yinghua, Liu, Ying, Liu, Meilin
• Format: Article
• Language: English
• Subjects: Air electrode; Air temperature; Chemical reduction; Computer applications; Electrochemical analysis; Electrochemistry; Electrode materials; Electrodes; Electrolysis; Electrolytic cells; Energy; Energy conversion; Energy dissipation; Energy loss; Fuel cells; Fuel technology; Hydrogen production; Oxygen; Oxygen evolution reactions; Oxygen reduction reactions; Renewable energy; Reversible solid oxide cells; Stability; Sustainability
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2021.120631

[Display omitted] •Improvement of electrochemical stability by doping Nb.•Enhancement of electrocatalytic activity by tuning Ba deficiency.•Peak power density of 1.5 and 1.0 W cm−2 at 600 °C for GDC and BZCYYb single cells.•Continuous operation of electrolysis cell for 1,000 h with minimal degradation. Solid oxide cells (SOCs) are considered the most efficient system for reversible conversion between chemical and electrical energy, thus having potential to be an attractive technology for a sustainable energy future. To achieve high round-trip efficiency, highly efficient and durable air electrode materials are needed to minimize energy loss associated with oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Here we report a bi-functional air electrode material, PrBa0.9Co1.96Nb0.04O5+δ, demonstrating outstanding electrochemical performance (e.g., achieving peak power densities of over 1.5 and 1 W cm−2, respectively, for Gd0.1Ce0.9O1.95 and BaZr0.1Ce0.7Y0.1Yb0.1O3-δ based fuel cells at 600 °C) while maintaining excellent stability (e.g., having a degradation rate of 40 mV per 1,000 h for H2O electrolysis cells). The excellent property of the new electrode is attributed to the improved stability from Nb doping and the enhanced electrocatalytic activity from tuning Ba deficiency, as confirmed by experimental results and computational analysis.