Masato Shirakata

Analysis of SiO Anodes for Lithium-Ion Batteries

The chemical structure of SiO (silicon monoxide) anodes has been analyzed using X-ray photoelectron spectroscopy (XPS). Vapor deposition was used to form SiO anodes on Cu film. XPS analysis was performed on anodes at eachof three stages: after deposition, after initial charge, and after discharge. The results of this analysis were then evaluated in terms of the anodes respective electrochemical characteristics. It has been found that some Si remains oxidized in the full charge state and that lithium silicates are formed. The lithium silicates serve as a buffer with respect to changes in anode volume.

Reaction Mechanism and Dielectric Properties in the Pb(Mg1/2W1/2)O3–Pb(Ni1/3Nb2/3)O3–PbTiO3 System

The effects of sample preparation conditions on dielectric properties of ceramics in the Pb(Mg1/2W1/2)O3–Pb(Ni1/3Nb2/3)O3–PbTiO3 system were investigated. The dielectric constant of this ceramic depended on the mixing condition of the raw powders, particularly. It was found to be lower when starting powders were poorly mixed than when they were properly mixed. This was attributed to the presence of a small amount of a Pb–W–O compound formed during preparation of dielectric powder when the mixing was insufficient. By increasing mixing time, the amount of Pb–W–O compound was decreased and the dielectric constant was increased.