Manipulating Polymer Configuration to Accelerate Cation Intercalation Kinetics for High‐Performance Aqueous Zinc‐Ion Batteries

Abstract

AbstractAqueous zinc‐ion batteries (ZIBs) with safety and cost superiority are becoming promising for energy storage; meanwhile, organic electrodes are attracting considerable interest. The development of organic ZIBs lies in the solution of challenging issues on impeded Zn2+ interfacial diffusion and the corresponding sluggish reaction kinetics. Herein, triquinoxalinylene (3Q) based homopolymer (P3Q) and triazine‐linked 3Q polymer (P3Q‐t) with enlarged conjugated planes are designed and prepared to reveal the impact of molecular configuration on Zn2+ transfer and coordination dynamics. Their ZIB performance and ion intercalation mechanism are systematically investigated by structural characterization, electrochemical measurement, and theoretical calculation. Specifically, P3Q shows interactions with both Zn2+ and H+, while P3Q‐t is discovered to selectively coordinate only with Zn2+. Moreover, P3Q‐t exhibits high conjugated planarity and electronegative fused‐rings pathways due to both intermolecular and intramolecular effects, leading to faster reaction dynamics and low Zn2+ transfer resistance. P3Q‐t affords a high capacity of 237 mAh g–1 at 0.3 A g–1. More importantly, such capacity can be retained for 45% at 15 A g–1 and an average 81% of capacity retention is achieved over 1500 cycles.