Ba-doped Pr2NiO4+δ electrodes for proton-conducting electrochemical cells. Part 3: Electrochemical applications

• Published in: International journal of hydrogen energy 2024-03, Vol.60, p.261-271
• Main Authors: Tarutin, Artem P., Gilev, Artem R., Baratov, Stanislav A., Vdovin, Gennady K., Medvedev, Dmitry A.
• Format: Article
• Language: English
• Subjects: Ln2NiO4; MIEC; Nickelates; Oxygen permeable membranes; PCECs; PCFCs; Protons
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2024.02.173

Layered nickelates, Ln2NiO4+δ, are promising electrode materials for many electrochemical applications, including solid oxide fuel cells and electrolysis cells. Although Ln2NiO4+δ has been extensively modified by various doping strategies to tune its functional properties, the partial substitution of Ln3+ with Ba2+ remains among the least studied routes. At the same time, such substitution is found to be favorable when Ln2NiO4+δ materials are used for protonic ceramic electrochemical cells based on Ba-containing proton-conducting electrolytes (i.e., BaCeO3, BaZrO3, Ba(Ce,Zr)O3). In this work, which is the third part of a systematic study, Pr2–xBaxNiO4+δ materials are used as electrodes for a proton ceramic fuel cell and as oxygen permeable membranes. The oxygen permeation experiments confirm that the compositions with x = 0.2 and 0.3 prevail over x = 0 and 0.1 in terms of their oxygen-ionic conductivity, while the electrochemical cell characterizations confirm the high electrochemical activity of the Pr1.8Ba0.2NiO4+δ electrode in both fuel-cell- and electrolysis-cell modes. Our research thus confirms that a Ba-doping strategy is highly promising for designing new Ln2NiO4+δ-based phases, simultaneously offering good chemical and thermal compatibility with state-of-the-art proton-conducting electrolytes and high electrochemical performance. [Display omitted] •Pr2–xBaxNiO4+δ (PBNx, 0 ≤ x ≤ 0.3) materials were electrochemically characterized.•PBNx were used as components of protonic ceramic cells and oxygen permeable membranes.•The obtained results indicate that Ba-doping improves the ionic transport of PBNx.•PBN0.2 and BPN0.3 can be considered as promising functional materials.