Ferrocene Boronic Acid‐Modified Polyvinylidene Fluoride as a High‐Performance Binder for Lithium–Sulfur Batteries

Abstract

Abstract Conventional polyvinylidene fluoride (PVDF) binders are unsuitable for sulfur cathodes in lithium–sulfur batteries due to their weak binding strength to sulfur, poor elasticity, and inability to confine lithium polysulfides (LiPSs). Herein, a ferrocene boronic acid (FcBA)‐modified PVDF binder is designed and prepared for high‐performance sulfur cathodes. The incorporation of FcBA enhances the mechanical properties of PVDF through hydrogen bonding‐induced crosslinking. The cyclopentadienyl rings in FcBA provide active sites for LiPS adsorption and catalytic transformation, thereby suppressing the shuttle effect. The resultant sulfur electrode with the PVDF/FcBA binder delivers a high areal capacity of over 4.3 mAh g −1 after 50 cycles at 0.1 C. Its pouch cells, with a sulfur loading of 3.8 mg cm −2 , exhibit an energy density of 336 Wh kg −1 at 0.01 C and a capacity retention of 85.3% after 100 cycles at 0.5 C. This work presents a practical strategy for designing functional binders to enhance the electrochemical performance of lithium–sulfur batteries.