2D Conjugated Metal–Organic Frameworks Bearing Large Pore Apertures and Multiple Active Sites for High‐Performance Aqueous Dual‐Ion Batteries

Abstract

2D conjugated metal–organic frameworks (2D c‐MOFs) with large pore sizes and high surface areas are advantageous for adsorbing iodine species to enhance the electrochemical performance of aqueous dual‐ion batteries (ADIBs). However, most of the reported 2D c‐MOFs feature microporous structures, with few examples exhibiting mesoporous characteristics. Herein, we developed two mesoporous 2D c‐MOFs, namely PA‐TAPA‐Cu‐MOF and PA‐PyTTA‐Cu‐MOF, using newly designed arylimide based multitopic catechol ligands (6OH‐PA‐TAPA and 8OH‐PA‐PyTTA). Notably, PA‐TAPA‐Cu‐MOF exhibits the largest pore sizes (3.9 nm) among all reported 2D c‐MOFs. Furthermore, we demonstrated that these 2D c‐MOFs can serve as promising cathode host materials for polyiodides in ADIBs for the first time. The incorporation of triphenylamine moieties in PA‐TAPA‐Cu‐MOF resulted in a higher specific capacity (423.4 mAh g‐1 after 100 cycles at 1.0 A g‐1) and superior cycling performance, retaining 96% capacity over 1000 cycles at 10 A g‐1 compared to PA‐PyTTA‐Cu‐MOF. Our comparative analysis revealed that the increased number of N anchoring sites and larger pore size in PA‐TAPA‐Cu‐MOF facilitate efficient anchoring and conversion of I3‐, as supported by spectroscopic electrochemistry and density functional theory calculations.