突破锂离子电池硅基阳极材料关键性能瓶颈的基础理论研究

In order to solve the key problems of structural and interfacial theories of next-generation silicon-based anode materials for lithium-ion batteries, the mechanism, kinetics and structure evolution of silicon-based materials during the electrochemical lithium deintercalation/intercalation are systematically studied. The design concepts about gradient silicon materials in view of both structural integrity and maximum capacity utilization as well as the “hard and soft” double-coating structure are established. The synergy among relevant factors and its long term stability are analyzed. Furthermore, novel electrolytes with high stability are developed and new polymer electrolyte/silicon interfaces are established. Meanwhile, the optimized electrochemical performance, long-term degradation and their dependence on the micro-/meso-structure are thoroughly investigated. Our investigation will provide theoretical foundation and scientific basis on modulating the electrochemical performance and breaking through the bottlenecks of silicon-based materials. In addition, this work is rather good for the enriching of scientific theories of electrochemistry, electrode materials, energy and other related fields.

针对影响锂离子电池新一代硅基阳极材料性能的结构与表界面核心理论问题，系统研究硅材料的电化学储锂机制、脱嵌锂动力学及结构演变，建立梯度硅材料兼顾结构完整性和容量最大化利用模式的设计理念，以及“刚柔相济”的“双层包覆结构”设计与构筑思想，分析相关因素间的协同性与优化匹配关系及其长效性机理，发展新型高稳定电解液，构建聚合物电解质/硅材料新体系，深入研究所创制的硅基材料在实际电池环境中的宏观性能表达与时变性及其与微介观结构的依赖性，为硅阳极材料的性能调控与突破实用化瓶颈提供理论基础和科学依据，同时丰富电池材料、能源等相关领域的科学基础理论。

为提升硅基负极结构和界面稳定性、突破硅负极材料在锂离子电池中的实用化瓶颈，本项目从硅基材料微纳结构、电极设计到全电池实际体系全角度研究硅材料的演化规律和性能调控理论。分析硅基材料中不同组分的主次关系、协同效应与优化匹配，结合多种表征技术、电化学分析方法和理论计算，深入探究了硅负极材料的脱嵌锂动力学机理及充放电过程中的结构和界面演化规律，确定了硅材料性能的本质限制因素，提出了一系列多尺度硅基组成与结构调控方法，开发了全新的电解液添加剂和粘结剂体系，全面提升了硅材料性能。本项目研究取得了显著的科学创新和实质性技术进展，为硅负极材料性能调控与突破实用化瓶颈提供理论基础和科学依据，同时丰富了电化学、材料物理化学、能源等相关领域的科学认知。