有机-无机复合固体电解质中锂离子输运性能研究

The composite solid electrolytes (CSEs) consisting of organic polymer electrolytes and inorganic state electrolytes have the merits of both materials, the softness of organic polymer and the high ionic conductivity of inorganic electrolyte, and also have the advantages of easy for scale up and excellent processability. By using the CSEs, the solid state batteries can achieve higher energy density while remaining excellent safety, which have broad application prospect in the market. However, the structure of the CSEs is relatively complicate, it contains not only organic and inorganic components, but also diverse of interfaces between cathode-electrolyte, electrolyte particles, and anode-electrolyte. This make its difficult to further understand the mechanism of ions transportation, and can not provide much guidance for the R&D of CSEs. In this proposal, we are going to use diverse of characterization methods to study the microscale structure and the ions transportation through the interfaces, by using the advanced facilities including: cross section and planar ion beam milling system, electric force microscopy, scanning EIS microscopy, XPS, high-temperature XRD. And we will optimize the CSEs based on the knowledge obtained in this project and fabricate a solid state battery prototype with good performance.

有机聚合物电解质与无机固体电解质材料复合形成的有机-无机复合固体电解质能兼顾聚合物电解质的柔性与无机电解质的高离子电导率，且具备容易大量制备，可加工性良好的优点。将这种复合电解质用于制备全固态电池能够在获得更高能量密度的同时获得良好的安全性能，是一种极有前景的电解质材料。但是，有机-无机复合固体电解质的结构相对复杂，除了有机组分、无机组分之外，还有正极-电解质、电解质颗粒之间、负极-电解质这些固固界面存在，因此对其离子传输机理研究还不够深入，难以对研发更优性能的复合电解质提供指导。申请人将采用离子束剖切结合电学扫描探针显微镜与扫描阻抗谱显微镜技术、nano-CT技术、逐层减薄XPS技术以及变温XRD等先进表征手段，在微米-纳米尺度下对复合固体电解质材料中的微观结构与界面过程进行多方位的表征，理解决定离子传输性能的关键因素，并对复合固体电解质材料进行优化改良，将其用于全固态锂电池的研发。

结合静电纺丝制备有机-无机固体电解质、固态电池制作、离子束切割技术、原位电学AFM技术，成功制备了包含完整锂离子通道的正极-固体电解质-负极的电池截面，并以此为基础，研究了固态电池工作过程中的锂离子输运、界面电势分布等信息，对理解限制锂离子在固态电池中传输速度的瓶颈问题有了深入的理解。在此基础上，对正极材料表面电解质包覆、金属锂负极导电网络、有机-无机复合体电解质材料以及半固态电池技术开展研究，获得了具有高安全性的半固态锂电池器件，兼具高能量密度与高安全性。发表学术论文12篇，获得授权专利9项。培养博士1名，硕士3名。研发成果应用于提高锂离子电池的安全性，为提高我国动力电池的安全提供了一种技术方案。