Design Donor‐Biacceptor Covalent Organic Framework with Primary‐Auxiliary Functional Sites for Enhanced 16‐Electron Sulfur Kinetic Reaction Process

ABSTRACT The catalytic conversion of lithium polysulfides (LiPSs) is crucial for realizing high‐energy‐density lithium–sulfur batteries. Herein, we propose a molecular cooperate engineering strategy to construct a hierarchical catalytic reaction chain for addressing the complex sulfur phase transitions and sluggish 16‐electron reaction kinetics. A covalent organic framework with a D‐A1‐A2 electronic structure was developed to generate a built‐in electric field (BIEF) via establishing intramolecular charge transfer (ICT) between bipolar functional groups. Theoretical calculations and in situ characterizations confirm that primary and auxiliary functional groups of COF can synergistically enable selective LiPSs capture while the BIEF‐facilitated electron transfer accelerates redox reactions of LiPSs, conferring reduced conversion energy barriers and mitigated shuttle effect. Moreover, the anchoring of the ─NO 2 group and hence the effect of the ─CF 3 group induce directional Li + deposition, ensuring the favored Li plating with epitaxial layered growth and suppressed dendrite formation. As a result, the Li symmetric cell demonstrates an ultra‐long lifespan (>16 000 h at 5 mAh cm −2 ) while Li–S batteries can achieve exceptional cycling stability (0.039% capacity decay per cycle over 1000 cycles). Meanwhile, the pouch cells deliver a high energy density of 395.6 Wh kg −1 with 90.2% capacity retention over cycling. This work presents a generalizable strategy for advancing multi‐electron redox systems.