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The Development of Silicon Nanocomposite Materials for Li-Ion Secondary Batteries

With the rapid progress and wide application of Li-ion batteries, commercial graphite anode can not satisfy the increasing demand for higher capacities. Like other anode materials with higher capacities, silicon materials as anodes remain serious problems for their large volume variations and poor cyclabilities during cycling. One of key problem is how to stabilize the performances of Si anode materials. Various influencing factors of volume variation of silicon anode materials have been reviewed, which consist of discharging voltage, amorphous or crystalline type, tube or pore microstructure, interlayer adhesion, buffering and protective layer materials and conductive agents. Another hot issue is on the preparation methods for silicon anode materials with high performance. It covers not only the technics of high purity silicon materials, including the predominant Siemens process of electronic-grade silicon, but also the techniques of silicon film anodes, which consists of butyl-capped silicon precursor, the template methods of nanostructure, magnetron sputtering, ball-milling. From the screening of existing silicon anode materials in the literatures, the preparation methods for promising Si anode materials and their prospects have been offered.