Products Cited in Publications Worldwide Nanoporous Phenazine-Based Covalent Organic Frameworks as Electrocatalytic Sulfur Hosts for Lithium–Sulfur Batteries

Nanoporous Phenazine-Based Covalent Organic Frameworks as Electrocatalytic Sulfur Hosts for Lithium–Sulfur Batteries

Pokhrel, Shiraj; Kaid, Mahmoud M; Palicherla, Abhinav; El-Kaderi, Hani M

DOI:

Abstract

The design of sulfur hosts in lithium–sulfur batteries (LSBs) plays a central role in enhancing the battery performance, stability, and sustainability. Here, we report a redox-active, nanoporous phenazine-based covalent organic framework (COF) termed DAPh-TFP COF, synthesized via an organic solvent-free terracotta method using (2,7-diaminophenazine-benzophenoneimine (DAPh-Bnzph) and Tri formyl phloroglucinol (TFP). By embedding phenazine units into the COF backbone, this metal-free host enables dual functionality: structural confinement and catalytic polysulfide conversion. To isolate the contribution of redox-active sites, a control COF, DAA-TFP COF, was synthesized based on redox-inactive 2,6-diaminoanthracene (DAA). Comparative electrochemical analysis of S@DAPh-TFP COF and S@DAA-TFP COF cathodes reveals that the phenazine-functionalized framework significantly enhances redox kinetics, capacity retention, and long-term cycling stability. Impressively, the S@DAPh-TFP COF exhibits a high capacity of 1079 mAh g-1 at 0.05 C and retains 76% of its initial capacity after 1000 cycles at 1 C, with a Coulombic efficiency >95% and a low-capacity fading rate of 0.025% per cycle. This study demonstrates the potential of metal-free redox-active COFs as multifunctional sulfur hosts, combining structural confinement with electrochemical activity for advanced LSBs applications, and serves as a viable approach for the metal-free cathode fabrication in rechargeable battery technologies.

Keywords

covalent organic frameworks ; redox-active host ; Lithium-Sulfur battery ; organic electrodes ; organic redox mediator

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A115676436848-40-598%

2,7-Dibromophenazine

39.0/100mg

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A192195131-14-698%

2,6-Diaminoanthracene-9,10-dione

18.0/10g

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A22772634374-88-495%

2,4,6-Trihydroxybenzene-1,3,5-tricarbaldehyde

12.0/250mg

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