Anchoring Π-D Conjugated Metal-Organic Frameworks with Dual-Active Centers on Carbon Nanotubes for Advanced Potassium-Ion Batteries.

Potassium-ion batteries (PIBs) are gradually gaining attention owing to their natural abundance, excellent security, and high energy density. However, developing excellent organic cathode materials for PIBs to overcome the poor cycling stability and slow kinetics caused by the large radii of K + ions is challenging. This study demonstrates for the first time the application of a hexaazanonaphthalene (HATN)-based two-dimensional π-d conjugated metal-organic framework (2D c-MOF) with dual-active centers (Cu-HATNH) and integrates Cu-HATNH with carbon nanotubes (Cu-HATNH@CNT) as the cathode material for PIBs. Owing to this systematic module integration and more exposed active sites with high utilization, Cu-HATNH@CNT exhibited a high initial capacity (317.5 mA h g -1 at 0.1 A g -1 ), excellent long-term cycling stability (capacity retention of 96.8% at 5 A g -1 after 2200 cycles), and outstanding rate capacity (147.1 mA h g -1 at 10 A g -1 ). The reaction mechanism and performance  were determined by combining experimental characterization and density functional theory (DFT) calculations. This contribution provides new opportunities for designing high-performance 2D c-MOF cathodes with multiple active sites for PIBs. This article is protected by copyright. All rights reserved.