东北师范大学吴兴隆团队制备了具有高度易接近的羰基和π阳离子效应的共价有机框架，用于先进钾离子电池。相关研究成果发表在2022年1月14日出版的《德国应用化学》。

共价有机框架（COF）具有坚固的多孔晶体结构，使其成为储能的诱人候选材料。

该文中，研究人员通过在单壁碳纳米管上原位缩合无水乙醚和胺，制备一种剥离聚酰亚胺COF复合材料（P-COF@SWCNT)用作钾离子电池（PIBs）的先进阳极。许多暴露在剥落框架上的活性位点和各种开放路径促进了P-COF@SWCNT中的高效离子扩散，同时防止在电解液中发生不可逆溶解。在充放电过程中，K⁺通过烯化和π-K⁺效应与酰亚胺基和萘环的羰基结合，并通过DFT计算和XPS、原位FTIR、Raman等证实。

因此，制备的P-COF@SWCNT阳极能够在0.05 A g^-1下实现438 mA h g^-1的极高可逆比容量和扩展稳定性。P-COF@SWCNT使更多人了解COF作为电极的设计和多功能性。

附：英文原文

Title: Covalent Organic Framework with Highly Accessible Carbonyls and π-Cation Effect for Advanced Potassium-Ion Batteries

Author: Xiao-Xi Luo, Wen-Hao Li, Hao-Jie Liang, Hong-Xia Zhang, Kai-Di Du, Xiao-Tong Wang, Xin-Fang Liu, Jing-Ping Zhang, Xing-Long Wu

Issue&Volume: 2022-01-14

Abstract: Covalent organic frameworks (COF) possess a robust and porous crystalline structure, making them an appealing candidate for energy storage. Herein, we report an exfoliated polyimide COF composite (P-COF@SWCNT) prepared by an  in-situ  condensation of anhydide and amine on the single-walled carbon nanotubes as advanced anode for potassium-ion batteries (PIBs). Numerous active sites exposed on the exfoliated frameworks and the various open pathways promote the highly efficient ion diffusion in the P-COF@SWCNT while preventing irreversible dissolution in the electrolyte. During the charging/discharging process, K  +  is engaged in the carbonyls of imide group and naphthalene rings through the enolization and π-K  +  effect, which is demonstrated by the DFT calculation and XPS, ex-situ FTIR, Raman. As a result, the prepared P-COF@SWCNT anode enables incredibly high reversible specific capacity of 438 mA h g  -1  at 0.05 A g  -1  and extended stability. The structural advantage of P-COF@SWCNT enables more insights into the design and versatility of COF as an electrode.

DOI: 10.1002/anie.202117661

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202117661