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

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 at 950 W kg, 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, 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.