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

초록

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.

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