锂离子垂直输运的复合固体电解质的开发及其在柔性固态锂硫电池中的应用研究

Flexible lithium batteries are ideal energy storage devices for wearable electronics, which has drawn much attention recently in energy storage field. Fabricating flexible lithium battery with high density, high safety and long cycle life is critically important due to the state-of-the-art of flexible lithium batteries with the traditional intercalation compounds cannot meet people’s demand in terms of energy density, safety and cycle life. This project aims at fabricating high energy density flexible solid lithium-sulfur batteries based on composite solid electrolyte with vertically aligned and continuous organic-inorganic interfaces for lithium ion fast transport obtained by introducing the vertically aligned zeolite arrays into the polymer matrix. Also, flexible lithium metal anode is achieved by introducing flexible skeleton. Integrated methods including manipulation of inorganic fillers microstructure and polymer-lithium salt system, solid/solid interface optimization will be used to construct high-performance flexible solid lithium-sulfur batteries in view of electrolyte, electrode and battery. The relationship between the microstructure and performance of solid electrolyte will be revealed. Also, the stability of Li metal/solid electrolyte interface will be investigated via X-ray photoelectron spectroscopy, solid nuclear magnetic resonance and electron microscopy techniques and the mechanism of solid electrolyte on lithium dendrite growth will be investigated combined with the theoretical simulation. This work paves way for fabricating high-performance flexible solid lithium-sulfur batteries.

柔性锂电池是可穿戴便携式电子产品理想的储能器件，是目前储能领域的研究热点。然而，基于插层化学的传统柔性锂电池难以满足人们对电池续航时间、安全性和使用寿命的要求。本项目提出基于复合固体电解质构筑高能量密度的柔性固态锂硫电池，采用垂直取向的分子筛阵列与聚合物复合构建垂直连续、高密度的有机-无机界面促进电解质中锂离子垂直快速传导，并引入骨架支撑制备柔性锂金属电极。拟综合“无机填料微观结构调控、聚合物-锂盐体系调控、固固界面优化”等手段，从“电解质-电极-电池”多层次出发构筑高性能的柔性固态锂硫电池，揭示电解质微观结构与宏观性能之间的构效关系，通过X射线光电子能谱、固体核磁、电镜等技术研究锂负极/电解质固固界面的稳定性，并结合有限元模拟探究固体电解质对锂枝晶生长的微观机制，该项目可为柔性固态锂硫电池的构筑提供重要的实验依据和理论指导。

柔性锂电池是可穿戴便携式电子产品理想的储能器件，是目前储能领域的研究热点。然而，基于插层化学的传统柔性锂电池难以满足人们对电池续航时间、安全性和使用寿命的要求。本项目创新性地基于复合固体电解质构筑高能量密度的柔性固态锂硫电池，通过有机-无机多相界面调控促进电解质中锂离子快速传导，并引入骨架支撑制备柔性金属锂电极，从“电解质-电极-电池”多层次出发构筑高性能的柔性固态锂硫电池。本项目成功开发出多种高离子电导率、宽电化学窗口、抗枝晶能力强的复合固体电解质和多种长寿命、稳定的柔性金属锂电极，并成功构筑了室温下可稳定循环的柔性固态锂硫电池。结合各种表征技术和DFT理论计算深入研究了固体电解质中锂离子传输机制，该项目为高性能复合固体电解质的设计及柔性固态锂电池的构筑提供了重要的实验依据和理论指导。