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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. Si-Containing Precursors for Si-Based Anode Materials of Li-Ion Batteries AbstractLithium-ion batteries with high energy density and large power output are in demand for consumer electronics, electric vehicles, and grid-scale stationary energy storage. Silicon is one of the most promising anode materials because it has 10 times higher specific capacity than that of the commercial graphitic carbon anode. Unfortunately, the practical utilization of silicon-based anode materials is still hindered by its low electronic conductivity and high capacity fading rate due to the large volume changes upon insertion and extraction of Li ions during cycling. Introducing porous structure, along with decreasing the dimension of Si-based materials to nanosize, is an effective way to address these problems. During the past decade, tremendous attention has been paid to improve Si anodes so as to give them better electrochemical performance. In this review, we focus the Si-containing precursors for preparation of Si-based anode materials.3

Silicon has been considered to be an attractive high-capacity anode material for next-generation lithium-ion batteries (LIBs). Currently, the commercial application of Si-based anodes is still restricted by its limited cycle life and rate capacity, which could be ascribed to the colossal volumetric change during the cycling process and poor electronic conductivity. We report the design of a unique Si-based nanocomposite of three-dimensional (3D) honeycombed graphene aerogel and the reduced graphene oxide sheets preprotected silicon secondary particles (SiNPs@rGO1). Through simple electrostatic self-assembly and hydrothermal processes, SiNPs are able to be wrapped with rGO1 to form reunited SiNPs@rGO1, and embedded into the backbone of 3D graphene honeycomb (rGO2). Such an intriguing design (namely, SiNPs@rGO1/rGO2) not only provides a conductive skeleton to improve the electrical conductivity, but also possesses abundant void spaces to accommodate the dramatic volume changes of SiNPs. Meanwhile, the outer rGO1 coats protect the inner SiNPs away from the electrolyte and prevent the destruction of the solid electrolyte interphase (SEI) film. As a result, the 3D honeycombed architecture achieves a high cyclability and excellent rate capability.