Radical covalent organic frameworks: A general strategy to immobilize open-accessible polyradicals for high-performance capacitive energy storage

Abstract Ordered π-columns and open nanochannels found in covalent organic frameworks (COFs) could render them able to store electric energy. However, the synthetic difficulty in achieving redox-active skeletons has thus far restricted their potential for energy storage. A general strategy is presented for converting a conventional COF into an outstanding platform for energy storage through post-synthetic functionalization with organic radicals. The radical frameworks with openly accessible polyradicals immobilized on the pore walls undergo rapid and reversible redox reactions, leading to capacitive energy storage with high capacitance, high-rate kinetics, and robust cycle stability. The results suggest that channel-wall functional engineering with redox-active species will be a facile and versatile strategy to explore COFs for energy storage. Efficient energy storage: A facile strategy for converting a conventional covalent organic framework (COF) into outstanding energy storage materials is described. The channel walls are provided with organic radicals in a controlled manner to achieve immobilized openly accessible polyradicals, leading to the development of a new, facile, and general way to design COFs for high-performance electrochemical energy storage.