Moderate Li–N Coordination Between Dibromopyrazine and Polysulfides Enables High‐Rate Lithium–Sulfur Batteries
Zhonghui Sun, Handing Liu, Xin Chao, Zhenghui Li, Ziyang Xie, Qisen Wang, Chaoxin Wu, Ruohan Jiang, Runjing Xu, Jiayun Zhang, Jinyu Yang, Ziyue Li, Dalin Sun, Fei Wang, Fang FangABSTRACT
Lithium–sulfur (Li–S) batteries are promising candidates for high‐energy storage, yet their practical application is limited by poor rate capability. To date, the conversion of lithium polysulfides (LiPSs) remains a major challenge due to the high energy barrier of the liquid–solid conversion from Li 2 S 4 to Li 2 S. Herein, to overcome this barrier, dibromopyrazine (DBP) was identified through screening as an effective electrolyte additive owing to its unique Br─C═N functionality, which weakens Li–S bonding via moderate Li–N coordination through the electron‐withdrawing effect of Br, thereby enabling effective LiPSs anchoring without impeding conversion. In the electrolyte containing 0.04 M DBP, the interaction favors Li 2 S 4 formation at 2.3 V and promotes three‐dimensional (3D) Li 2 S deposition. Consequently, the Li–S coin cells deliver a high capacity of 785 mAh g −1 at the high rate of 6 C and a low capacity decay rate of 0.09% per cycle over 1000 cycles at 1 C. A 2 Ah pouch cell also demonstrates stable cycling over 100 cycles at 0.5 C. This work highlights a coordination‐modulated moderate‐interaction strategy for accelerating LiPSs conversion in Li–S batteries.