RESUMO
Atomistic analysis of the ion transport in polymer electrolytes for all-solid-state Li-ion batteries was performed using molecular dynamics simulations to investigate the relationship between Li-ion transport and polymer morphology. Polyethylene oxide (PEO) and poly(diethylene oxide-alt-oxymethylene), P(2EO-MO), were used as the electrolyte materials, and the effects of salt concentrations and polymer types on the ion transport properties were explored. The size and number of LiTFSI clusters were found to increase with increasing salt concentrations, leading to a decrease in ion diffusivity at high salt concentrations. The Li-ion transport mechanisms were further analyzed by calculating the inter/intra-hopping rate and distance at various ion concentrations in PEO and P(2EO-MO) polymers. While the balance between the rate and distance of inter-hopping was comparable for both PEO and P(2EO-MO), the intra-hopping rate and distance were found to be higher in PEO than in P(2EO-MO), leading to a higher diffusivity in PEO. The results of this study provide insights into the correlation between the nanoscopic structures of ion solvation and the dynamics of Li-ion transport in polymer electrolytes.
RESUMO
Recently, allergy to titanium has been reported. However, the patch test reagent for titanium is not standardized yet. The form and density of the patch test reagent for titanium was changed and examined in a group of normal subjects and a group with skin disease. The following conclusions were obtained. 1. A reagent which was composed of pure titanium powder and vaseline was not preferable because its form was a stimulant. 2. If the form of the titanium powder was not sharp even though it was not spherical, it did not cause a stimulated reaction. 3. It is suggested that TiCl4 0.1% is preferable as a patch test reagent for titanium.