Ion electrokinetic regulation in electrolyte is of great significance to alleviating polysulfide shuttling and dendritic growth in lithium-sulfur (Li-S) batteries. Inspired by the tunable solute-polymer interactions of ion exchange membrane, herein we implant an ion-selective “skin” constructed by isocyanoethyl methacrylate grafted polyethylenimine (PEI-IEM) in electrolyte via in situ gelation. This tailored skin endows the PEI-IEM-based gel polymer electrolyte (GPE) with a hyper-branched network with abundant polar groups, thus upgrading the electrolyte flame resistance, realizing obstruction on polysulfide migration, and facilitating Li⁺ transport against uneven deposition. Consequently, the PEI-IEM-based GPE empowers enhanced S electrochemical reversibility and high security, as evidenced by a 10 Ah Li-S pouch cell with a low electrolyte/S ratio of 2.6 and 1.4× excess Li anode that delivers an energy density of 412.7 Wh kg⁻¹. This proof-of-concept study provides new insights for tailoring the ionic behaviors of electrolyte to achieve high-energy and safe Li-S batteries.

电解质中的离子电动调节对于缓解锂硫（Li-S）电池中的多硫化物穿梭和枝晶生长具有重要意义。受离子交换膜的可调节溶质-聚合物相互作用的启发，在此我们通过原位凝胶在电解质中植入由甲基丙烯酸异氰基乙酯接枝聚乙烯亚胺（PEI-IEM）构成的离子选择性“皮肤”。这种定制的皮肤赋予了基于PEI-IEM的凝胶聚合物电解质（GPE）具有丰富的极性基团的超支化网络，从而提高了电解质的阻燃性，实现了对多硫化物迁移的阻碍，并促进了Li ⁺防止不均匀沉积的运输。因此，基于 PEI-IEM 的 GPE 增强了 S 电化学可逆性和高安全性，10 Ah Li-S 软包电池具有 2.6 的低电解质/S 比和 1.4 倍的过量 Li 负极证明了这一点，其能量密度为412.7 瓦时公斤^-1。这项概念验证研究为调整电解质的离子行为以实现高能量和安全的锂硫电池提供了新的见解。