Si-based composite anode materials for lithium ion batteries

As a kind of promising anode material for lithium ion batteries, silicon-based materials have been attracted much attention. The poor cycling stability due to the huge volume change during lithiation and delithiation and the low initial coulombic efficiency are the critical problems that limit their commercial application. Nanocrystallization, alloying and carbon-coating are effective measures to solve these issues. This article reviews the progress in silicon/ compound composites in which TiB₂, TiN and TiC act as the matrices, silicon-metal composites including Fe-Si, Cu-Si and Ni-Si, and silicon/carbon composites. In respect of the research on silicon/carbon composites, emphasis is put on the preparation methods like pyrolysis, milling, milling-pyrolysis and chemical polymerization, and the carbon sources such as polypyrrole, polyvinylchloride(PVC), polyacrylonitrile (PAN), resorcinol-formaldehyde resin, citric acid and epoxy resin. In addition, the progress in Si/carbon nanotubes composite materials is also discussed.