A Dual‐Conductive and Robust Binder With Cross‐Linked Network for Enhanced Sulfur Cathode

ABSTRACT

The sulfur (S) cathode of lithium–sulfur (Li–S) batteries is limited by poor electrical conductivity, polysulfide dissolution, sluggish conversion kinetics, and large volume variation during cycling. These issues are closely coupled with inadequate electronic/ionic transport and insufficient mechanical integrity of the cathode architecture—factors in which the binder plays a critical role. Herein, a dual‐conductive and mechanically robust cross‐linked binder, composed of polyacrylic acid, graphene and polyvinyl alcohol (c‐PGP), is designed to simultaneously regulate sulfur redox chemistry and electrode integrity. The cross‐linked polymer network provides strong mechanical stability to accommodate sulfur volume expansion, while graphene incorporation establishes continuous electronic pathways. Meanwhile, abundant polar functional groups enable strong chemical immobilization of soluble polysulfides, suppressing their diffusion and mitigating the shuttle effect. As a result, the S cathode with the c‐PGP binder exhibits improved electrolyte wettability, reduced interfacial resistance, accelerated Li ⁺ diffusion, and promoted Li ₂ S nucleation/decomposition. Li–S cells with the c‐PGP binder demonstrate lower polarization, enhanced rate capability and stable cycling performance over 600 cycles at 0.5 A/g. This work highlights the critical role of multifunctional binder design in advancing high‐performance S cathode.