Covalent organic frameworks: From materials design to electrochemical energy storage applications

Abstract

Covalent organic frameworks (COFs), with large surface area, tunable porosity, and lightweight, have gained increasing attention in the electrochemical energy storage realms. In recent years, the development of high‐performance COF‐based electrodes has, in turn, inspired the innovation of synthetic methods, selection of linkages, and design of the topological structures. This review aims to present an overview of the recent advances in designing COF materials for various energy storage technologies. The fundamentals of COF materials, including synthetic chemistry, linkage diversity, and structure design, are first introduced. An in‐depth understanding of the charge storage mechanism and the structure‐property relationships of the COF electrodes is subsequently provided, highlighting their designing strategies in the latest energy storage applications. The last section of this review discusses the challenges COFs are facing and outlines new directions that could advance COF research in emerging energy technologies.

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

“…[476][477][478] Third, COFs have lower material density and higher energy density compared to MOFs and other metal-based materials. 479 Also, the good thermostability and electrochemical stability of COFs undoubtedly can extend the cycle life of batteries. 480 To date, COFs have already been used to make lithium-ion, [481][482][483] sodium-ion, [484][485][486] potassiumion, 487,488 zinc-ion, 489,490 lithium-CO 2 , 491 lithium-sulfur, [492][493][494] and zinc-air batteries.…”

“…510 The development of next-generation electrocatalysts with enhanced stability and catalytic activity is an ongoing challenge in energy conversion and storage research. 511,512 Electrocatalysts based on metal-free materials and inexpensive metals This journal is © The Royal Society of Chemistry 2022 such as graphene, 513,514 MXenes, 515,516 MOFs, [517][518][519][520] and COFs 126,479 are currently an active research area. Due to the well-defined and programmable structures, the study of COFelectrocatalysts can truly correlate the structure and properties and promote a deeper understanding of electrocatalytic principles, thus providing guidance for the development and optimization of novel electrocatalysts.…”

Covalent Organic Framework for Rechargeable Batteries: Mechanisms and Properties of Ionic Conduction

“…COFs, possessing well‐defined pore structure, low density, large surface area, desired chemical motifs, and excellent stability, have achieved great successes in the rechargeable battery application. [ 3,22,23,44–49,120–130 ] Moreover, the emerging ion‐conducting COFs with excellent ionic conductivity and high cation transfer number can reduce the battery polarization and improve the charging/discharging kinetics of electrodes. [ 131–143 ] The distinctive directional selectivity of ionic conduction in COFs is obviously different from the typical inorganic solid conductors and polymer conductors, so that COFs are suitable for diverse battery applications, including lithium‐ion, [ 144–166 ] lithium–sulfur, [ 167–208 ] sodium‐ion, [ 209–214 ] potassium‐ion, [ 215–219 ] lithium–CO 2 , [ 220–223 ] zinc‐ion, [ 224–230 ] zinc–air batteries, [ …”

Porous organic polymers for high-performance supercapacitors

“…17 POPs generally involve amorphous hyper-crosslinked polymers (HCPs), 18,19 polymers of intrinsic microporosity (PIMs), 20,21 conjugated microporous polymers (CMPs), 22–25 porous aromatic frameworks (PAFs), 26,27 and crystalline covalent organic frameworks (COFs). 28–31 Among them, COFs are crystalline POPs constructed by the orderly linkage of organic molecules. Compared to MOFs, COFs have exhibited lighter molecular weight and higher energy density because of their light elements (C, H, N, O, B, etc.…”