锂离子电池硅碳复合负极结构的研究进展

Lithium-ion batteries have the advantages of high energy density, good rate performance, long cycle life and low self-discharge rate, and are currently the most important type of mobile energy storage. The anode of commercial batteries is mainly made of graphite, and its theoretical capacity is low, which is the main bottleneck limiting the capacity of lithium-ion batteries. Silicon, on the other hand, is characterized by high theoretical capacity, suitable operating voltage, high natural abundance, etc. Therefore, it is a typical electrode material for the new generation of lithium-ion batteries. However, due to the large volume changes of silicon anodes during charging and discharging, low initial Coulombic efficiency, relatively poor electrical conductivity, and unstable solid electrolyte interface, silicon-based anodes have significant stability problems that hinder practical applications. To solve these problems, modifying silicon anodes with carbon is a more commercial approach. In this paper, the silicon / carbon anode materials in recent years are divided into 0D-nanoparticles, 1D-nanowires and nanotubes, 2D-nanosheets and 3D-micron spheres according to the structure and size of silicon materials, and the structures and electrochemical properties of carbon-based silicon / carbon composites are discussed. In addition, the progress and limitations of the existing silicon / carbon composite anodes are summarized and the prospects for industrialization in this field are highlighted.