In-situ engineered three-dimensional hydrogen-bonded co-binder network to boost lithium–sulfur batteries

The development of cathodes with high sulfur loading is essential for practical high-energy lithium–sulfur batteries. The binder functions as a polymeric framework that integrates active materials and conductive agents, while preserving electrode integrity and influencing electrochemical behavior. In lithium–sulfur systems, binders with polar functional groups that interact strongly with lithium polysulfides are crucial to suppress the shuttle effect and enhance cycling stability. Here, we design a multifunctional binder, poly(amic acid)–dextrin copolymer (PDB), which incorporates amide, carboxyl, hydroxyl, and imide groups within a three-dimensional network. This architecture provides mechanical robustness, immobilizes polysulfides, accelerates redox kinetics, and improves interfacial contact among electrode components. As a result, lithium–sulfur cells with PDB deliver a specific capacity of 590 mAh g^{− 1} after 100 cycles at 0.5 C, and maintain 357 mAh g^{− 1} under a high sulfur loading of 9.0 mg cm^{− 2} after 100 cycles at 0.2 C. This work demonstrates that multifunctional binder systems play a pivotal role in advancing lithium–sulfur batteries toward scalable, high-performance, and cost-effective energy storage technologies.