Si-containing precursors for Si-based anode materials of Li-ion batteries: A review

Lithium-ion batteries with high energy density are in demand for consumer electronics, electric vehicles, and grid-scale stationary energy storage. Si is one of the most promising anode materials due to its extremely high specific capacity. However, the full application of Si-based anode materials is limited by poor cycle life and rate capability resulted from low ionic/electronic conductivity and large volume change over cycling. In recent years, great progress has been made in improving the performance of Si anodes by employing nanotechnology. The preparation methods are essentially important, in which the precursors used are crucial to design and control the microstructure for the Si-based materials. In this review, we provide comprehensive summary and comment on different Si-containing precursors for preparation of nanosized Si-based anode materials and focus on the corresponding electrochemical performances in lithium-ion batteries. Bulk sized silicon, silicon wafer and silicon microparticles are generally used as starting materials to synthesize porous or nanosized silicon, and the routes for the synthesis are rather mature and commercially available. Silica is also commonly used to form silicon by conversion through a facile magnesiothermic reduction. Silica derivation from natural resources, especially from rice husks, is much more sustainable and lower cost than alternative methods, which attracts considerable research attention. In addition, gaseous Si-based sources like SiH4, Si2H6 and SiHxCly, liquid silicon sources like trisilane and phenylsilane and elemental silicon have successfully used to prepare nanosized or carbon-coated silicon. Further considerations on massive production possibility have also been presented.