Synergism of Flame‐Retardant, Self‐Healing, High‐Conductive and Polar to a Multi‐Functional Binder for Lithium–Sulfur Batteries
Mingliang Liu, Peng Chen, Xinchen Pan, Shencheng Pan, Xiang Zhang, Yan Zhou, Min Bi, Jingwen Sun, Shaolin Yang, Aleksandr L. Vasiliev, Paweł J. Kulesza, Xiaoping Ouyang, Jianbo Xu, Xin Wang, Junwu Zhu, Yongsheng Fu
Abstract
Abstract In this work, a multifunctional binder with self‐healing, flame retardant, high conductivity, and abundant polar groups is prepared by the free radical polymerization method and applied to lithium–sulfur (Li‐S) batteries to achieve high safety and exceptional electrochemical performance. The self‐healing characteristic of binder induced by intermolecular hydrogen bonds and SS dynamic covalent bonds can repair volume expansion cracks. The polar groups and excellent conductivity endue binder with strong chemisorption on polysulfides and fast charge transportation, which can effectively inhibit the shuttle effect and accelerate polysulfides redox kinetics. More important, the considerable flame retardant performance of binder can improve the safety of the LiS batteries. As a result, the LiS cells using FHCP binder deliver an outstanding cycle stability of a high‐capacity retention rate of 85% after 100 cycles at 0.2 C, and a high reversible area specific capacity of 5.25 mAh cm –2 at a sulfur loading of 4.72 mg cm –2 and a correspondingly lean electrolyte condition (E/S ratio = 6 µL mg –1 ).