Binders are of vital importance in stabilizing the cathodes to enhance the cycling stability of lithium-sulfur (Li-S) batteries. However, conventional binders are typically confronted with the drawback of inability for adsorbing lithium polysulfide (LiPS), thus resulting in severe active material losing and rapid capacity fading. Herein, a novel water-soluble hyperbranched poly(amidoamine) (HPAA) binder with controllable hyperbranched molecular structure and abundant amino end groups for Li-S battery is designed and fabricated, which can improve efficient adsorption for LiPS and stability of the sulfur cathodes. Besides, the strong intermolecular hydrogen bonds in HPAA binder can contribute to the structural stability of S cathode and integration of the conductive paths. Therefore, the Li-S battery with this functional binder exhibits excellent cycle performance with a capacity retention of 91% after 200 cycles at 0.1 C. Even at a high sulfur loading of 5.3 mg cm⁻², a specific capacity of 601 mA h g⁻¹ can also be achieved. Density functional theory (DFT) calculation further demonstrates that the enhanced electrochemical stability derives from the high binding energy between amino groups and LiPS and the wide electrochemical window (6.87 eV) of HPAA molecule. Based on the above all, this functional polymer will lighten a new species of binders for eco-friendly sulfur cathodes and significantly promote the practical applications of high-performance Li-S batteries.

粘合剂对于稳定阴极以增强锂硫（Li-S）电池的循环稳定性至关重要。然而，常规粘合剂通常面临不能吸附多硫化锂（LiPS）的缺点，因此导致严重的活性材料损失和快速的容量衰减。本文设计并制备了一种新型可控的超支化分子结构，氨基端基含量丰富的水溶性超支化聚（酰胺基胺）（HPAA）粘合剂，用于Li-S电池，可以提高LiPS的有效吸附能力和硫阴极的稳定性。此外，HPAA粘合剂中的强分子间氢键可有助于S阴极的结构稳定性和导电路径的整合。因此，^-2，也可以实现601 mA hg ^-1的比容量。密度泛函理论（DFT）的计算进一步表明，增强的电化学稳定性源自氨基与LiPS之间的高结合能以及HPAA分子的宽电化学窗口（6.87 eV）。综上所述，这种功能性聚合物将减轻用于环保型硫阴极的新型粘合剂的使用，并显着促进高性能Li-S电池的实际应用。