A fast ceramic mixed OH−/H+ ionic conductor for low temperature fuel cells

Zou, Peimiao; Iuga, Dinu; Ling, Sanliang; Brown, Alex J.; Chen, Shigang; Zhang, Mengfei; Han, Yisong; Fortes, A. Dominic; Howard, Christopher M.; Tao, Shanwen

Abstract

Low temperature ionic conducting materials such as OH− and H+ ionic conductors are important electrolytes for electrochemical devices. Here we show the discovery of mixed OH−/H+ conduction in ceramic materials. SrZr0.8Y0.2O3-δ exhibits a high ionic conductivity of approximately 0.01 S cm−1 at 90 °C in both water and wet air, which has been demonstrated by direct ammonia fuel cells. Neutron diffraction confirms the presence of OD bonds in the lattice of deuterated SrZr0.8Y0.2O3-δ. The OH− ionic conduction of CaZr0.8Y0.2O3-δ in water was demonstrated by electrolysis of both H218O and D2O. The ionic conductivity of CaZr0.8Y0.2O3-δ in 6 M KOH solution is around 0.1 S cm−1 at 90 °C, 100 times higher than that in pure water, indicating increased OH− ionic conductivity with a higher concentration of feed OH− ions. Density functional theory calculations suggest the diffusion of OH− ions relies on oxygen vacancies and temporarily formed hydrogen bonds. This opens a window to discovering new ceramic ionic conducting materials for near ambient temperature fuel cells, electrolysers and other electrochemical devices.

Citation

Zou, P., Iuga, D., Ling, S., Brown, A. J., Chen, S., Zhang, M., Han, Y., Fortes, A. D., Howard, C. M., & Tao, S. (2024). A fast ceramic mixed OH−/H+ ionic conductor for low temperature fuel cells. Nature Communications, 15(1), Article 909. https://doi.org/10.1038/s41467-024-45060-1

• Journal Article Type: Article
• Acceptance Date: Jan 12, 2024
• Online Publication Date: Jan 30, 2024
• Publication Date: 2024
• Deposit Date: Feb 13, 2024
• Publicly Available Date: Feb 14, 2024
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 15
• Issue: 1
• Article Number: 909
• DOI: https://doi.org/10.1038/s41467-024-45060-1
• Keywords: Fuel cells; Solid-state chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/30667723
• Publisher URL: https://www.nature.com/articles/s41467-024-45060-1