Indium‐Doping‐Induced Nanocomposites with Improved Oxygen Reaction Activity and Durability for Reversible Protonic Ceramic Electrochemical Cell Air Electrodes

• Published in: Advanced functional materials 2024-12, Vol.34 (49), p.n/a
• Main Authors: Du, Zhiwei, Xu, Kang, Zhu, Feng, Xu, Yangsen, He, Fan, Gao, Hui, Gong, Wenjie, Choi, YongMan, Chen, Yu
• Format: Article
• Language: English
• Subjects: air electrode; Chemical reduction; Doping; Durability; Electrochemical cells; Electrode materials; Electrodes; Electrolysis; Electrolytic cells; Energy conversion efficiency; Fuel cells; Indium‐doping; Nanocomposites; oxygen evolution reaction; Oxygen evolution reactions; oxygen reduction reaction; Oxygen reduction reactions; Perovskites; Reaction kinetics; reversible protonic ceramic electrochemical cells
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202409188

Reversible protonic ceramic electrochemical cells (R‐PCECs) are very promising as energy conversion and storage devices with high efficiency at intermediate temperatures (500–700 °C). Unfortunately, the sluggish reaction kinetics on air electrodes severely hamper the commercial application of R‐PCECs. In this work, an In‐doped PrBaCo2O5+δ air electrode is developed with a designed formula of PrBaCo1.9In0.1O5+δ, which however consists of a dominated double perovskite PrBa0.95Co1.85In0.09O5+δ and a minor cubic perovskite BaCo0.85In0.15O3‐δ phase, as suggested by the XRD refinements. The formation of nanocomposites induced by the In‐doping has markedly improved the activity of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), due likely to the increased oxygen vacancies, enhanced the oxygen surface exchange and bulk diffusion capabilities when compared to the bare PrBaCo2O5+δ. Excellent electrochemical performances in fuel cell (FC) mode (2.25 W cm−2) and electrolysis cell (EC) mode (−4.41 A cm−2 at 1.3 V) are achieved on the single cells with such nanocomposite air electrodes at 700 °C. In addition, promising durability tests of cells in modes of FC (100 h), EC (100 h), and cycling (210 h) are demonstrated at 600 °C. This In‐doped strategy provides a novel approach to developing new air electrode materials. This study reports an In‐doped PrBaCo2O5+δ air electrode consisting of a dominated double perovskite PrBa0.95Co1.85In0.09O5+δ and a minor cubic perovskite BaCo0.85In0.15O3‐δ phase with high electrochemical performance. This In‐doped strategy provides an effective approach to developing new air electrode materials.