Defective 2D Covalent Organic Frameworks for Postfunctionalization

Abstract

Defects are deliberately introduced into covalent organic frameworks (COFs) via a three‐component condensation strategy. The defective COFs (dCOF‐NH2‐Xs, X = 20, 40, and 60) possess favorable crystallinity and porosity, as well as have active amine functional groups as anchoring sites for further postfunctionalization. By introducing imidazolium functional groups onto the pore walls of COFs via the Schiff‐base reaction, dCOF‐ImBr‐Xs‐ and dCOF‐ImTFSI‐Xs‐based materials are employed as all‐solid‐state electrolytes for lithium‐ion conduction with a wide range of working temperatures (from 303 to 423 K), and the ion conductivity of dCOF‐ImTFSI‐60‐based electrolyte reaches 7.05 × 10−3 S cm−1 at 423 K. As far as it is known, it is the highest value for all polymeric crystalline porous material based all‐solid‐state electrolytes. Furthermore, Li/dCOF‐ImTFSI‐60@Li/LiFePO4 all‐solid Li‐ion battery displays satisfactory battery performance under 353 K. This work not only provides a new methodology to construct COFs with precisely controlled defects for postfunctionalization, but also makes them promising candidate materials as all‐solid‐state electrolytes for lithium‐ion batteries operate at high temperatures.

2D Materials for All‐Solid‐State Lithium Batteries

“…Due to its porous structure and functionalization, perovskite under 353 K and retains 98.3% capacity after 40 cycles with 97.5% coulombic efficiency. [175] In addition, dCOF will have a wide range working temperature range from 303 to 423 K. [175] In the other work, Li et al designed another type of 2D COF (Im-COF-Br) which was synthesized by Schiff base reaction, and the building block is imidazolium-based monomers. This new COF has some charac-teristics, such as positive charge in the COF skeletons, tunable counter-anions, and 5.57 nm pore sizes.…”

In situ construction of redox-active covalent organic frameworks/carbon nanotube composites as anodes for lithium-ion batteries

“…[23][24][25][26] Moreover, the uniform open channel of COF networks is benecial for the electrolyte infusion and ion/ electron transport. [27][28][29][30][31] Recently, COFs have been explored as electrode materials for LIBs with improved electrochemical performance compared with traditional small organic compound electrodes. [32][33][34][35] These studies demonstrated that the overall specic capacity of anodes largely relies on the accessible Li-interactive site concentration and the electroconductivity of COFs.…”

A single-ion conducting covalent organic framework for aqueous rechargeable Zn-ion batteries

“…This well-ordered porous structure of TpPa-SO 3 Zn 0.5 could contribute to facilitating uniform and directional ion transport. [27][28][29][30][31][32][33] The stability of TpPa-SO 3 Zn 0.5 in water was evaluated as a requirement for use in aqueous batteries. Aer treatment in H 2 O at 100 C for 7 days, TpPa-SO 3 Zn 0.5 still showed the characteristic XRD pattern (Fig.…”

“…COFs have been regarded as appealing ion transport media owing to their ordered porous structure, functionalities and structural stability. [27][28][29][30][31][32][33] A zinc sulfonated COF (TpPa-SO 3 Zn 0.5 ; Fig. 1a) is synthesised to build well-dened directional channels in which covalently tethered and delocalised sulfonates play key roles in realising single Zn 2+ transport.…”