Due to its high energy density, lithium-sulfur (Li-S) battery is considered as the most promising candidate for the energy storage systems, but its practical application is hindered by the dissolution of lithium polysulfides in the electrolyte. In this work, N-bromophthalimide (C₈H₄NO₂Br, NBP), an aromatic molecule with carbophilic, sulfiphilic, lithiophilic, and solvophilic nature, is introduced into active graphene (AG) to fabricate the sulfur composite cathode. The carbophilic NBP is anchored readily on the AG surface via π−π stacking interaction. During discharging, the dissolved lithium polysulfide anion (LiS⁻_n) is grafted into the sulfiphilic NBP spontaneously via S_N2 substitution reaction to form C₈H₄NO₂S_nLi, which brings the dissolved LiS⁻_n back to the AG surface in the composite cathode. Moreover, the lithiophilic and solvophilic nature of NBP improve the wettability of the porous composite cathode, and the electrolyte molecule is easily penetrated into the micro-mesopores of AG to facilitate the diffusion of the electrolyte. Thus, NBP, as a multi-functional compound in Li-S battery, can immobilize LiS⁻_n and enhance the diffusion of the electrolyte. The above features of NBP endow the sulfur composite cathode with improved electrochemical performance in the cycling stability.

由于其高能量密度，锂硫（Li-S）电池被认为是储能系统的最有希望的候选者，但其实际应用却由于多硫化锂在电解质中的溶解而受到阻碍。在这项工作中，将具有嗜碳，亲硫，亲硫和亲溶剂性质的芳族分子N-溴邻苯二甲酰亚胺（C ₈ H ₄ NO ₂ Br，NBP）引入活性石墨烯（AG）中，以制备硫复合阴极。亲碳NBP通过π-π堆积相互作用很容易地锚定在AG表面。在放电过程中，溶解的多硫化锂阴离子（LiS ^- _n）自发接枝到亚氨基NBP中通过S _N 2取代反应形成C ₈ H ₄ NO ₂ S _n Li，使溶解的LiS ^- _n返回复合阴极中的AG表面。而且，NBP的亲脂性和亲溶剂性改善了多孔复合阴极的润湿性，并且电解质分子容易渗透到AG的微中孔中以促进电解质的扩散。因此，NBP作为Li-S电池中的多功能化合物，可以固定LiS ^- _n并增强电解质的扩散。NBP的上述特征使硫复合阴极在循环稳定性方面具有改善的电化学性能。