阳极
共价键
氢键
蒽醌
水溶液
互变异构体
铵
共价有机骨架
化学
离子
烯醇
无机化学
材料科学
化学工程
光化学
分子
有机化学
催化作用
电极
物理化学
工程类
作者
Jiahui Liu,Keyan Guo,Wen Guo,Jiaqi Chang,Yongsheng Li,Fuxi Bao
标识
DOI:10.1002/anie.202424494
摘要
Covalent organic frameworks (COFs) have recently been emerged as promising anode candidates for aqueous ammonium ion batteries (AAIBs), but suitable COFs need to be developed and the energy storage mechanisms need to be further investigated. Here we report an anthraquinone carbonyl‐containing COF as anode for AAIBs, which exhibits a high specific capacity of 141 mAh g‐1 at 0.1 A g‐1 and good cycling stability with 90% retention after 8000 cycles at 6 A g‐1. We find that the anthraquinone carbonyls (denoted as C=O1) with superconjugated structure in the COF can form hydrogen bonds with NH4+ ions, thus serving as optimal sites and providing the major contribution to NH4+ ion storage, whereas another type of carbonyls (denoted as C=O2) in the same COF suffers from enol‐keto tautomerism, which prevents the formation of hydrogen bonds and is therefore unfavourable for NH4+ ion storage. This is further verified by the theoretical calculations where the hydrogen bonding rate of C=O1 groups is much faster than that of C=O2. This work not only provides insights into understanding the mechanism of NH4+ ion storage, but also offers new ideas for the design of advanced COF‐based materials for AAIBs.
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