Oxidation pathways towards Si amorphous layers or nanocrystalline powders as Li-ion batteries anodes

Abstract

Silicon nanomaterials are obtained by an original approach based on the direct solution phase oxidation of a solid state Zintl phase NaSi used as silicon precursor. Alcohols with different alkyl chains are chosen as oxidizing agents. The materials are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The most relevant parameter lies in the amorphous character of the silicon nanoparticles produced by this route. Amorphous nature of silicon is one of the key features for succeeding in the improvement of anodes for Li-ion batteries. The Si nanostructures have been tested as anodic materials for lithium ion batteries.