In Situ Deformation Topology of COFs with Shortened Channels and High Redox Properties for Li–S Batteries. (28th November 2022)

• Record Type: Journal Article
• Authors: Wang, Qiaomu; Tang, Kaifei; Liao, Qiaobo; Xu, Yang; Xu, Haocheng; Wang, Yandong; Wang, Peng; Meng, Zhen; Xi, Kai
• Is Part Of: Advanced functional materials. Volume 33:Number 6(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-28
• Subjects: covalent organic frameworks -- high redox -- lithium–sulfur batteries -- stacking weakening -- topology deformations; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202211356
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Covalent organic frameworks (COFs) with various topologies are typically synthesized by selecting and designing connecting units with rich shapes. However, this process is time‐consuming and labour‐intensive. Besides, the tight stacking of COFs layers greatly restrict their structural advantages. It is crucial to effectively exploit the high porosity and active sites of COFs by topological design. Herein, for the first time, inducing in situ topological changes in sub‐chemometric COFs by adding graphene oxide (GO) without replacing the monomer, is proposed. Surprisingly, GO can slow down the intermolecular stacking and induce rearrangement of COFs nanosheets. The channels of D‐ [4+3] COFs are significantly altered while the stacking of periodically expanded framework is weakened. This not only maximizes the exposure of pore area and polar groups, but also shortens the channels and increases the redox activity, which enables high loading while enhancing host‐guest interactions. This topological transformation to exhibit the structural features of COFs for efficient application is an innovative molecular design strategy. Abstract : For the first time, to change the established topology of D‐ [4+3] covalent organic frameworks (COFs) by adding GO, is induced. Benefiting from the weak stacking of the new topology and regular channels, D‐ [4+3] COFs possess more accessible specific surface area and active groups. The new materials prepared as high‐load Li–S battery cathodes effectively suppress polysulphide shuttle and demonstrate high stability.