硅具有4200 mAh•g-1的理论储锂容量，而其储锂过程产生的体积应力导致硅负极的稳定性难以达到要求。尽管通过纳米化、构造缓冲体积膨胀空间结构、硅碳复合等能有效改进硅基负极稳定性，但其仍存在SEI膜不稳定、硅储锂活性表面利用率低、缓冲应力体积空间导致负极体积比容量低等不足。本项目从硅基负极材料组成、微观结构角度出发，基于Si高储锂容量，SiOx稳定SEI膜性质，SiC缓解体积应力的力学特性，设计构筑基于多相界面的SiOx@Si@SiC多相结构材料。通过界面设计调控，提高Si储锂活性表面及利用率，通过多相体系微观结构设计调控，发挥多相材料各单元在锂离子储运过程的优势及它们的协同效应。在建立精准构筑SiOx@Si@SiC多相结构材料及其界面方法基础上，研究SiOx@Si@SiC组成、结构、比表面、孔结构等对其锂离子电池负极性能的影响机制，开发基于多相界面设计的硅基高性能锂离子电池负极材料。

Silicon has a theoretical capacity of 4200 mAh•g-1 for lithium ions storage, however, the stress caused by the volume expansion of lithiation of silicon results a low stability of silicon based anode of lithium ion battery. Although nanosizing silicon, constructing the spatial structure to buffer the volume expansion, and preparing the composites of silicon and carbon materials can effectively improve the durability of silicon based anode, there are the shortages of unstable solid electrolyte interface film, low utilization of active silicon surface for lithium ions storage and the low volumetric capacity of lithium ions storage caused by constructing more space to buffer the volume expansion of silicon lithiation. In this project based on the composition and structure of silicon anode materials, we will design and construct the multi-phase system of SiOx@Si@SiC materials according to the characteristics of high lithium ions storage capacity of Si, the advantage of stabilizing SEI film of SiOx and the property of alleviating volumetric stress of SiC. By designing and tuning the interface of the multi-phase system, it will enhance the active surface of lithium ions storage of Si and its utilization. By designing and tuning the micro-structure of SiOx@Si@SiC system, it will exploit the advantages of the unit consisting of multi-phase system and their synergistic effects in the storage and transfer of lithium ions. On the basis of building SiOx@Si@SiC system accurately, the effects of composition, structure, specific surface area and pore structure of SiOx@Si@SiC system on the anodic properties of lithium ion battery using SiOx@Si@SiC as electrode materials will be studied to develop the Si anode materials based lithium ion battery with excellent performance.