Structural Analysis of Pure and Electrochemically Lithiated SiO Using Neutron Elastic Scattering

Neutron elastic scattering was used to determine the structure of as-received and lithiated amorphous SiO which has been proposed as an anode material for lithium ion secondary batteries. Based on a comparison between the total radial distribution functions [RDF(r)] of SiO and SiO 2 , it was suggested that amorphous SiO is composed of a three-dimensional SiO 4 tetrahedral network similar to silica (SiO 2 ) glass and metallic silicon clusters, and that the latter were finely dispersed in the SiO 4 matrix. On the other hand, electrochemically lithiated SiO showed a typical lithium negative correlation together with the disappearance of the Si-Si correlation in the RDF(r) which indicated that lithium predominantly reacted with the metallic silicon to form Li-Si alloys.