Covalent organic frameworks as electrode materials for rechargeable metal‐ion batteries

Abstract

Covalent organic frameworks (COFs), as a class of crystalline porous polymers, featuring designable structures, tunable frameworks, well‐defined channels, and tailorable functionalities, have emerged as promising organic electrode materials for rechargeable metal‐ion batteries in recent years. Tremendous efforts have been devoted to improving the electrochemical performance of COFs. However, although significant achievements have been made, the electrochemical behaviors of developed COFs are far away from the desirable performance for practical batteries owing to intrinsic problems, such as poor electronic conductivity, the trade‐off relationship between capacity and redox potential, and unfavorable micromorphology. In this review, the recent progress in the development of COFs for rechargeable metal‐ion batteries is presented, including Li, Na, K, and Zn ion batteries. Various research strategies for improving the electrochemical performance of COFs are summarized in terms of the molecular‐level design and the material‐level modification. Finally, the major challenges and perspectives of COFs are also discussed in the aspect of large‐scale production and electrochemical performance improvements.

Density Functional Theory Study of Bilayer Borophene-Based Anode Material for Rechargeable Lithium Ion Batteries

“…The value of the capacity (930.2 mA h/g) in P 6̅ m 2 bilayer borophene can be comparable to the counterpart monolayer borophene, which is 1860 mA h/g for the fully lithiated phase Li 0.75 B without vacancy defects, 1984 mA h/g for β 12 , and 1240 mA h/g for χ 3 deficiency borophene . In contrast to other common 2D materials, the capacity of bilayer borophene electrodes has a competitive advantage, close to that in GaN (938 mA h/g), COF (211–1830 mA h/g), , and 1.7–2.9 times larger than MXene anodes, including Ti 3 C 2 (320 mA h/g) and Mo 2 C (400–526 mA h/g), , much larger than traditional metal dichalcogenides anodes such as MoS 2 of 230 mA h/g and GeS of 256 mA h/g, respectively. , …”

Advances in organic cathode materials for aqueous multivalent metal-ion storage

“…Due to their atomically precise pre-designable reticular chemistry, covalent organic frameworks (COFs) hold great potential as promising cathodes for multivalent metal-ion storage applications. 94,95 For example, Alshareef's group introduced quinone functionalities into the 1,4,5,8,9,12-hexaazatriphenylene-derived COF material. 78 Experimental and computational analysis further revealed that the introduction of redox-active quinone within the COF elevated the Zn 2+ /H + -storage capability against H + and pushed up the (dis-)charge potential for the aqueous ZnSO 4 system.…”

Assessing n‐type organic materials for lithium batteries: A techno‐economic review

“…[41][42][43] Materials belonging to the organosulfide class are mainly characterized by the reversible breaking and reformation of a disulfide bond, the same type of reaction present in lithium-sulfur batteries [44][45][46] ; notably, a few examples exploiting thiocarbonyl groups are also present. 47,48 These redox-active motifs can be found in small molecules as well as macromolecular structures, such as linear or cross-linked polymers, 16 covalent organic frameworks (COFs), 49,50 or metal organic frameworks (MOFs). 51,52 These two latter classes of three-dimensional, π-conjugated, crystalline coordination polymers (fully organic and metal-organic hybrids, respectively) have been widely investigated as battery materials, and their electrochemical properties are connected to the employed redox-active ligands.…”