球型Si基碳包覆锂离子电池负极材料研究进展

Research Progress of Spherical Si-based Carbon-coated Anode Materials forLithium-ion Batteries

硅基材料包括单质硅及其氧化物SiO_(x)(0≤x≤2),具有理论容量高、工作电位低、对环境友好、储量丰富等特点,有望取代石墨成为新一代锂离子电池负极材料。然而,硅基材料在充放电过程中的体积膨胀效应始终不能避免,硅氧化物的低电导率也限制了硅基材料的发展。为解决上述问题,研究人员提出了各种各样的解决方法,其中,在硅基材料表面进行碳包覆的方法具有很广阔的应用前景并被广泛研究。本文先简要介绍了各硅基材料的储锂机理和失效问题,再从最典型的球型结构设计的角度切入,详细介绍了不同的球型碳包覆结构,如核壳结构、蛋黄壳结构、多孔结构等,并讨论了Si基碳包覆负极材料未来商业化的发展趋势和要面对的挑战。

Silicon-based materials,including elemental silicon and its oxide SiO_(x)(0≤x≤2),are expected to replace graphite as a new generation of anode material for lithium-ion batteries because of their high theoretical capacity,low working potential,environment-friendly and abundant reserves.However,the volume expansion effect of silica-based materials in the process of charge and discharge is inevitable.In addition,the low conductivity of silica-based materials also limits the development of silica-based materials.In order to solve the above problems,researchers have proposed a variety of solutions,among which the carbon coating method on the surface of silicon-based materials has a great application prospect and has been widely studied.This paper first outlines the lithium storage mechanism and failure problems of each silicon-based material,and then summarizes different spherical carbon coating structures in detail from the perspective of the most typical spherical structure design,such as core-shell structure,yolk-shell structure,porous structure,etc.The future development trend of carbon-coated anode materials based on Si and the challenges to be faced are discussed.