Heteroporous Donor‐Acceptor Covalent Organic Framework Cathode for High‐Rate‐Capacity Lithium‐Ion Battery

Abstract

Abstract Covalent organic frameworks (COFs), a conspicuous porous material, harvest great promise for rechargeable batteries, owing to well‐defined pore structure and structural precision. However, designing high‐rate‐capacity COF cathode by balancing ions diffusion kinetics and electron transport kinetics based on the framework and pore chemistry remains a challenge. Here, a heteroporous donor‐acceptor (D‐A) engineering is proposed to design one novel kind of COF (HDA‐COF) with optimized electronic conductivity (σ e ) and ionic conductivity (σ ions ). The heteroporous D‐A framework featuring with triangle‐like micropores for promoted electron transport and enlarged hexagonal‐like mesopores for facilitated ions diffusion rate. HDA‐COF demonstrates high compatibility with high σ e and σ ions verified by the combination of experimental results and theoretical calculations. Notably, HDA‐COF displays favorable fast‐charging performance with 104 mAh g −1 (277 Wh kg −1 , 5 A g −1 ) and shorter charge time (75 s), maintaining steadily cycling for 1000 cycles at 5 A g −1 . Also, it delivers high discharge capacity of 259 mAh g −1 (627 Wh kg −1 , 0.05 A g −1 ). This work offers in‐depth insights in constructing high‐rate‐capacity COF cathode by synchronously optimizing σ e and σ ions within a heteroporous D‐A engineering.