基于局域化离子型功能隔膜的锂硫电池构筑及其电化学行为研究

锂硫电池是下一代高效电化学储能体系的有力竞争者，受到了学术界和工业界的广泛关注。然而，其基于固液相转化的电化学反应特征伴随着显著的穿梭效应，严重降低了电池的实际能量密度和循环稳定性。对此，通过隔膜的改性设计，合理管理中间产物多硫化锂的溶解和扩散行为，是兼顾反应动力学和可逆性，提升锂硫电池综合性能极具潜力的发展方向。.本项目以局域化离子型功能隔膜为研究对象，发展简单、高效、可定制的隔膜制备方法，获得兼具优良导锂和阻硫性能的隔膜材料；结合理论计算、理化表征和电化学分析，系统性研究局域化离子结构与锂离子及多硫离子间的相互作用方式和内在机制，总结相关构效关系，构建合理的离子选择能力评估体系；揭示离子选择性渗透对正负极形貌、结构及反应过程的影响，并据此进一步优化隔膜、电极和电池各项参数，获得兼具高能量密度、长循环寿命和良好倍率性能的锂硫电池，为先进功能隔膜以及高性能锂硫电池的开发提供科学指导。

Lithium-sulfur battery is a highly competitive candidate for next-generation high-efficiency energy storage, and has drawn extensive attentions from both academic and industrial communities. However, the solid-liquid conversion mechanism is accompanied by the shuttle effect, which seriously deteriorates the practical energy density and cyclability. In this regard, separator modification that rationally regulates the dissolution and diffusion behaviors of the intermediate polysulfides is a highly promising pathway towards the balanced reaction kinetics and reversibility, as well as improving the overall battery performance. .In this proposal, we focus specifically on the localized ionic functional separator, developing its facile, efficient, and customizable preparation with the concurrent fulfillments of good lithium conduction and sulfur obstruction. Combining theoretical calculations, physicochemical characterizations, and electrochemical techniques, this project will systematically investigate the respective interactions of the localized ionic structures with lithium ion and polysulfide anions, as well as the underlying mechanism. The corresponding structure-property relationship will be summarized, while a rational evaluation on the ion selectivity will be also established. Moreover, this project also aims to reveal the implications of the ion selective permission on the morphology, structure, and reaction process of both cathode and anode, based on which the related parameters will be further optimized towards high energy density, long service life, and good rate capability. This project is expected with good instructive significance for the development of advanced separators as well as high-performance lithium-sulfur batteries.