Fluoride- based hydrogen bond chemistry in a layered double hydroxide cathode toward highperformance aqueous NH4+storage

• 成果类型: Article
• 署名作者: Sun, Fang-Fang; Guan, Xinwei; Huang, Zi-Hang; Han, Xu; Li, Hui; Ma, Tianyi
• 署名单位: Liaoning University; Royal Melbourne Institute of Technology (RMIT); Chinese Academy of Sciences; Ningbo Institute of Materials Technology & Engineering, CAS
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8768
• DOI: 10.1073/pnas.2414112122
• 发表日期: 2025-02-25
• 关键词: energy; reduction

摘要

In aqueous ammonium- ion storage, hydrogen bonds play a pivotal role in the reversible insertion/extraction ofNH4 + within transition metal oxides/hydroxides. Although fluorine (F) is known for its strong electronegativity and potential to form robust hydrogen bonds with NH4+, its specific influence on NH4 + storage remains unexplored. Herein, we systematically investigate the effects of F- based hydrogen bond chemistry within a layered double hydroxide matrix, where F species are introduced and subsequently partially removed via an electrochemical method. Our findings demonstrate that while increasing F doping content accelerates NH4 + diffusion due to F's strong electronegativity, it also triggers crystal shrinkage and depresses storage capacity. To this end, controlled partial removal of F, employing a lye- assistant electrochemical strategy, induces expanded interlayer spacing and distinct edge lattice tearing, thereby facilitating improved NH4+ accommodation. The retained F sites couple with emerging exposed O sites maintain a high hydrogen bonding capability, which is further enhanced by the formation of highly active, curved hydroxyl groups centered around F sites. These manipulations significantly boost the NH4 + storage performance of the electrode, providing insights into leveraging the strongest F- based hydrogen bond chemistry in developing highperformance ammonium- ion energy storage devices.