An Active and Robust Air Electrode for Reversible Protonic Ceramic Electrochemical Cells
Yucun Zhou, Enzuo Liu, Yu Chen, Yuchen Liu, Lei Zhang, Weilin Zhang, Zheyu Luo, Nicholas Kane, Bote Zhao, Luke Soule, Yinghua Niu, Yong Ding, Hanping Ding, Dong Ding, Meilin Liu
Abstract
Reversible protonic ceramic electrochemical cells (R-PCECs) are a promising option for efficient and low-cost generation of electricity and hydrogen. Commercialization of R-PCECs, however, hinges on the development of highly active and robust air electrodes. Here, we report an air electrode consisting of PrBa0.8Ca0.2Co2O5+δ and in situ exsolved BaCoO3−δ nanoparticles (PBCC–BCO) that shows minimal polarization resistance (∼0.24 Ω cm2 at 600 °C) and high stability when exposed to humidified air with 3−50% H2O. An R-PCEC utilizing PBCC-BCO demonstrates remarkable performances at 600 °C: achieving a peak power density of 1.06 W cm–2 in the fuel cell mode and a current density of 1.51 A cm–2 at 1.3 V in an electrolysis mode. More importantly, the R-PCECs demonstrate an exceptionally high durability over 1833 h of continuous operation in the electrolysis mode. This work offers an efficient approach to design of high-performance and durable electrodes for R-PCECs.