Regulating Electronic Microenvironments in Fully‐Conjugated Covalent Organic Framework for High‐Rate Ion Storage

ABSTRACT Covalent organic frameworks (COFs) have attracted extensive attention in rechargeable lithium‐ion batteries (LIBs) due to their structural designability, well‐defined porosity, and customizable ion storage capabilities. However, the inherently poor electron transport, along with sluggish ion‐diffusion kinetics, particularly at high current density, limits the electrochemical reaction kinetics, thereby impeding the full active sites utilization. Here, an electronic microenvironment regulation strategy through chemical structural evolution is proposed to construct a novel fully‐conjugated COF (BTTP‐COF) with localized dipole polarization. This material design boosts the electron transport driving force, thereby contributing to higher electron conductivity, and also reduces ion diffusion resistance based on the fully‐conjugated framework. Benefiting from enhanced dipole polarization, which generates an additional built‐in driving force for charge separation and electron transport, BTTP‐COF achieves a higher active site availability with an accelerated reaction rate. Notably, BTTP‐COF displays a favorable specific capacity of 297 mAh g −1 (658 Wh kg −1 ) at 0.1 A g −1 , together with exceptional calendar lifespan at 20 A g −1 with an ultralow capacity fading rate of 0.0009% per cycle (>10 000 cycles). This work provides an effective example for constructing high‐rate performance COF materials by synchronously optimizing electron transport and ion diffusion through electronic microenvironment regulation.