What is it about?
In several nano-porous materials and their composites, enhancement of ionic conductivity has been reported and several mechanisms having different origins have been proposed so far. In the present work, ionic motion of Li ions in porous lithium disilicates is examined by molecular dynamics simulation in the constant volume conditions and the enhancement of the dynamics is predicted.
Featured Image
Why is it important?
Structures and dynamics of ions in a nano-porous system were characterized and visualized to clarify the mechanism of the enhancement. The diffusion coefficient of Li ions has shown the maximum in the medium density (and porosity) region, and near the maximum, shortening of the nearly constant loss region in the mean squared displacement of ions as well as changes of the structures of the coordination polyhedra, LiOx is found. It suggests that the loosening of the cage, which increases the jump rate of ions, is an origin of the enhancement. When larger voids are formed with a further decrease of density, more tight cages are reconstructed and the diffusion coefficient decreases again.
Perspectives
The mechanism thus clarified is useful to control the dynamics of ions in porous materials. It is noteworthy that the explanation is not based on the percolation of the path only or formation of boundaries, although the former also affects the dynamics.
Dr Junko Habasaki
Tokyo Institute of Technology
Read the Original
This page is a summary of: Molecular dynamics study of nano-porous materials—Enhancement of mobility of Li ions in lithium disilicate, The Journal of Chemical Physics, November 2016, American Institute of Physics,
DOI: 10.1063/1.4967874.
You can read the full text:
Contributors
The following have contributed to this page
