Si-Based Composite Anode Materials for Li-Ion Batteries

Silicon is one of the most attractive anode materials for lithium ion batteries on account of its low discharge potential and the highest theoretical capacity for lithium storage. However, the large volume effect, poor electronic conductivity and incompatibility with the conventional electrolyte hinder its commercial applications. So far, strategies to overcome these hinders include designing the composition and microstructure of silicon active materials to suppress the volume change and improve the conductivity, developing new binders and electrolyte additives and exploring new current collectors and suitable electrode structures. There are mainly two methods to improve the silicon active materials. One is to decrease the scale of active Si domain to nanoscale, the other is to fabricate the composite structures. This paper summarizes the recent progress in silicon based composite materials, including Si-nonmetal composites and Si-metal composites, as well as some researches of our group, and discusses the technological bottlenecks and development trends.