原位光固化Li-13X基复合固态电解质的制备及性能研究

Preparation and properties of in situ curing Li-13Xbased composite solid electrolytes

固态锂金属电池因其高能量密度和安全性,被认为是最有潜力取代传统锂离子电池的储能设备.离子液体修饰的多孔材料具有自身界面相容性和较高离子电导率等优点,渐渐成为固体电解质领域中的热点材料.文中首先对Na-13X型分子筛进行锂化处理,然后再填充锂离子液体后形成Li-IL@Li-13X导体.Li-13X丰富的路易斯酸性位点能够固定离子液体中的TFSI~-阴离子,其骨架结构可作为离子传输通道增加自由迁移的锂离子量.将Li-IL@Li-13X加入到光聚合物胶中,利用光固化技术得到了Li-IL@Li-13X基复合固态电解质.具有最佳锂离子液体含量的复合固态电解质在45℃、0.1 mA·cm^(-2)电流密度时可以稳定电镀-剥离1 400 h,证明该电解质具有良好的抑制锂枝晶能力.此外,通过原位工艺将该复合固态电解质固化在正极上,可以解决固固界面的接触问题,在400次循环后的容量保持率高达91.3%.本工作验证了分子筛与离子液体相结合作为一种导体材料可以用于原位光固化领域,为制备新型固态电解质提供了一种新思路.

Solid state lithium metal batteries are considered to be the most potential energy storage device to replace traditional lithium ion batteries due to their high energy density and safety.Ionic liquid modified porous materials have gradually become a hot topic in the field of solid electrolytes owing to their nanointerface compatibility and high ionic conductivity.This work employs the lithification treatment on Na-13X molecular sieve filled with lithium ion liquid to form the Li-IL@Li-13X.Li-13X with rich Lewis acid sites can immobilize TFSI anions in ionic liquids,and its skeleton structure can serve as ion transport channels,increasing the amount of freely migrating lithium ions.The Li-IL@Li-13X-base composite solid electrolyte was obtained upon an adding of Li-IL@Li-13X into UV-polymer adhesive by a UV curing technology.The composite solid electrolyte was stably plated and peeled at a current density of 0.1 mA·cm^(-2) at 45℃for 1400 hours,demonstrating its excellent ability to inhibit lithium dendrites.In addition,the composite solid electrolyte was solidified on the positive electrode using an in-situ process,which optimizes the solid-solid contact interface problem and achieves a capacity retention rate of 91.3%after 400 cycles.The integration of molecular sieve and ionic liquid as a conductor material by in-situ UV curing technology provides a new idea for fabricating solid-state electrolytes.