Heterointerfacial Charge Modulation of p‐Type Covalent Organic Frameworks on Graphene Achieving High‐Performance Cl ⁻ Ion Storage with Ultralong Cycling Life

Abstract

Abstract The charge and ion transport dynamics, storage capacity, and cycling performance of Faradaic Cl − ion storage electrodes have recently constrained advancements in supercapacitor (SC) and capacitive deionization (CDI). Herein, a high‐performance p‐type COF (TAPA‐COF)‐based Cl − ion storage material (TAPArGO) with exceptional cycling stability was synthesized via an in situ condensation reaction utilizing graphene as a conductive substrate. The interfacial coupling involving graphene and TAPA‐COF increases the interfacial electron density, boosting local charge accumulation and Cl − ion storage capacity. Additionally, the dual conductive strategy of incorporating graphene and extended π‐electron delocalization of TAPA‐COF enhances the redox kinetics, while the triphenylamine N redox centers and flexible graphene network improve cycling stability. Consequently, the Cl − ion asymmetric SC employing the TAPArGO‐75 positive electrode achieves a specific energy output of 52.4 Wh kg −1 at 950 W kg −1 , with exciting cycling durability retaining 96.8% of the initial capacity after 100 000 cycles. Furthermore, the hybrid CDI system based on the TAPArGO‐75 positive electrode demonstrates a specific adsorption capacity of 55.0 mg g −1 , along with remarkable cycling desalination/regeneration ability (99.8% after 200 desalination/regeneration cycles). This study expands the application potential of COF‐based materials for high‐performance Cl − ion storage.