纳米复合单锂离子导体固态电解质的设计制备及其在锂金属电池中的应用研究

The uncontrollable lithium dendrite growth has permanently prevented the practical application of lithium metal anode. Taking advantage of Y type initiator and the controllable polymerization, two kinds of functional polymer chains have grown on the surface of nanosilica (SiO2), including functional block polymer (FBP) with plastic properties and crosslinking function, and single lithium ion conductor (SLICs) providing lithium-ion. The project realizes controllable preparation of hybrid solid electrolytes (HSE) based on FBP/SLICs@SiO2. Then we put forward a new method for the HSE preparation based on SLICs, and research the basic application of HSE for lithium metal batteries. The project intends to explore the mechanism for improving ionic conductivity in each functional component of HSE, and illustrate the factors how the structure of HSE to affect the ionic conductivity. We will research the synergistic effects of HSE on the inhibition of lithium dendrite growth, and reveal the mechanism of synergistic inhibition. On the basis of controllable preparation, we will study the influence of the structure of HSE for the lithium ion storage or transportation and clarify the relevance of the novel nanostructure of HSE and electrochemical properties, and develop high performance solid electrolyte materials with independent intellectual property rights. This project can enrich and develop the scientific theories for the preparation of HSE materials, and provide an opportunity to solve the problems of safety and performance of lithium metal batteries, which has a great theory value and scientific significance.

锂枝晶不可控的生长，严重阻碍了锂负极的应用。通过可控聚合技术，利用Y型引发剂，在二氧化硅(SiO2)表面生长两种高分子，其中功能嵌段聚合物(FBP)提供朔化性能与交联功能，单锂离子导体(SLICs)提供锂离子，实现FBP/SLICs@SiO2复合固态电解质（HSE）的可控制备。提出基于单锂离子导体制备HSE的新方法，进一步研究HSE在锂金属电池中的基础应用。项目拟研究HSE中各功能组分对提高离子电导率的作用机制，阐明影响离子电导率的结构因素；研究HSE中高锂离子迁移数与高机械强度对抑制锂枝晶生长的协同效应，揭示协同抑制的机理；在可控制备的基础上，研究HSE的结构对锂离子存储、运输的规律，阐明HSE的纳米结构与电化学性能的关联性，研制出具有自主知识产权的高性能固态电解质材料。本项目可以丰富和发展HSE的制备科学理论，为解决锂金属电池的安全性能与倍率性能提供机会，具有重要理论价值和科学意义。

锂枝晶不可控的生长，严重阻碍了锂负极的应用，固态电解质作为一个有效的解决策略，受到广泛的关注；然而，传统固态电解质面临牺牲机械性能提升室温离子电导率的挑战，难以实现锂金属负极的有效防护。本项目通过可控聚合技术，在不同维度的纳米材料上接枝功能高分子和单锂离子导体，如二氧化硅(SiO2)、埃洛石（HY）与细菌纤维素（BC）等，获得了一系列新型的单锂离子导体复合固态电解质（HSPEs），提出了高性能HSPEs制备以及锂负极有效防护的新方法。项目研究HSPE中各功能组分对提高离子电导率的作用机制，阐明影响离子电导率的结构因素；阐明HSPE的纳米结构与电化学性能的关联性，研制出具有优异阻燃性能，高室温离子电导率（3.6×10-4 S cm-1），高锂离子迁移数（>0.85）以及优异力学强度的高性能HSPEs材料。本项目的完成为从分子水平设计制备高性能HSPEs提供科学依据和理论指导，同时为解决锂金属电池的安全性能能提供机会，具有重要理论价值和科学意义。