浅述锂离子电池硅碳负极材料复合结构

Brief Discussion on Composite Structure of Silicon-carbon Anode Material for Lithium-ion Battery

硅基材料作为最具发展前景的锂离子负极电池材料之一,其具有较高的理论比容量和优异的快充性能,符合目前新能源汽车的发展需求。但由于其在充放电的嵌脱锂过程中体积发生严重膨胀,使得电极材料结构被破坏,继而出现粉化脱落现象,制约了该材料的商业化应用。有学者提出若将碳和硅2种材料复合,即可得到容量高、导电性能和循环性能佳的负极材料。笔者先分析了硅基负极的储锂机制,对硅碳负极复合材料的核壳结构、蛋黄壳结构、多孔结构、嵌入结构4种结构设计进行了简单总结,并针对不同结构的特点进行分析。最后对硅碳负极复合材料未来的研究及低成本的产业化发展进行展望。

As one of the most promising lithium ion anode battery materials,silicon-based materials have high theoretical specific capacity and excellent fast charging performance,which meets the development needs of new energy vehicles.However,due to the serious expansion of the volume during the lithium insertion/extraction process,the structure of the electrode material is destroyed,and then the phenomenon of pulverization and shedding occurs,which restricts the commercial application of the material.Some scholars have proposed that if the two materials of carbon and silicon are combined,the anode material with high capacity,good electrical conductivity and cycle performance can be obtained.In this paper,the lithium storage mechanism of silicon-based anode is analyzed.The core-shell structure,yolk-shell structure,porous structure and embedded structure of silicon-carbon anode composites are briefly summarized,and the characteristics of different structures are analyzed.Finally,the future research and low-cost industrial development of silicon-carbon anode composites are prospected.