A Synergistic Three-Phase, Triple-Conducting Air Electrode for Reversible Proton-Conducting Solid Oxide Cells
Weilin Zhang, Yucun Zhou, Xueyu Hu, Yong Ding, Jun Gao, Zheyu Luo, Tongtong Li, Nicholas Kane, Xiao‐Ying Yu, Tanguy Terlier, Meilin Liu
Abstract
High Resolution Image Download MS PowerPoint Slide Reversible proton-conducting solid oxide cells (R-PSOCs) have the potential to be the most efficient and cost-effective electrochemical device for energy storage and conversion. A breakthrough in air electrode material development is vital to minimizing the energy loss and degradation of R-PSOCs. Here we report a class of triple-conducting air electrode materials by judiciously doping transition- and rare-earth metal ions into a proton-conducting electrolyte material, which demonstrate outstanding activity and durability for R-PSOC applications. The optimized composition Ba 0.9 Pr 0.1 Hf 0.1 Y 0.1 Co 0.8 O 3−δ (BPHYC) consists of three phases, which have a synergistic effect on enhancing the performance, as revealed from electrochemical analysis and theoretical calculations. When applied to R-PSOCs operated at 600 °C, a peak power density of 1.37 W cm –2 is demonstrated in the fuel cell mode, and a current density of 2.40 A cm –2 is achieved at a cell voltage of 1.3 V in the water electrolysis mode under stable operation for hundreds of hours.