Dual‐Enhanced Iodine Confinement and Conversion of Single‐Atom Mn‐N <sub>3</sub> ‐C Catalyst for Long‐life Electrolytic Zn‐I <sub>2</sub> Batteries
Dedong Jia, Zelong Shen, Hua Tan, Kun Zheng, Mingming Tao, Hongqiang Li, Yaohui Lv, Yuanhua Sang, Lianbo Ma, Weijia Zhou, Xiaojun He
Abstract
ABSTRACT Aqueous zinc‐iodine (Zn‐I 2 ) batteries are gaining increasing attention because of their environmental friendliness, high capacity, and cost‐effectiveness. The performance of Zn‐I 2 batteries is generally limited by the polyiodide shuttle effect and sluggish conversion kinetics. In this study, a highly efficient catalyst of single‐atom Mn anchored into energetic MOFs (MET‐6) derived porous carbon matrix (SAMn‐N 3 ‐C) is developed for a stable electrolyte Zn‐I 2 battery. The rich mesoporous structure offers ample space for electrolyte (KI) infiltration and abundant sites for physical adsorption toward iodine species. Simultaneously, the atomically dispersed SAMn‐N 3 catalytic sites not only enable strong chemical combination to suppress the shuttle effect of polyiodides, but also reduce the activation energy of the I − /I 2 conversion to accelerate kinetics. Consequently, the prototypical Zn‐I 2 battery equipped with SAMn‐N 3 ‐C cathode delivers a high discharge capacity of 336.2 mAh g −1 at 1 A g −1 and exceptional cycling stability with 95.7% capacity retention after 50 000 cycles at 20 A g −1 . Moreover, the assembled Zn‐I 2 soft‐pack cell achieves an areal capacity of 25.6 mAh and stable operation for 100 times. This work demonstrates a hybrid strategy to design ideal iodine hosts with dual‐enhanced iodine confinement and conversion, facilitating the practical application of Zn‐I 2 batteries.