As an organic solvent, N-butyl acetate (Junsei Chemical Co., Ltd., Chuo-ku, Tokyo, Japan) was used in order to dissolve the materials. Three types of aluminum oxides (Sigma-Aldrich Corporation) with acidic, neutral, and basic surface groups as fillers were also used. As salt, LiCF 3SO 3 (Sigma-Aldrich Corporation) was dried and stored in a desiccator under nitrogen. Louis, MO, USA) with a number average molecular weight ( M n) of 170,000 was used as received without undergoing further purification process. Polystyrene (Sigma-Aldrich Corporation, St. In this work, the ionic conductivity of PS-Al 2O 3 composite SPE according to the salt content was checked, and the effect of Al 2O 3 type and content on ion conduction properties in PS-based composite SPE was investigated. Moreover, Al 2O 3 can cause conductivity enhancement depending on the nature of the filler surface group. However, in this new composite SPE consisting of polystyrene and having nonpolar groups, LiCF 3SO 3 and Al 2O 3 with polymer-in-salt system, the transport of cations is done by ion-hopping through an ion percolation path made of high content lithium salt instead of segmental motion. From this point of view, a polymer which has nonpolar groups is not suitable for the polymer matrix in common SPEs. The cations can move between coordinating sites in one chain or in neighboring chains, promoted by the segmental motion. The polar groups dissolve lithium salt and coordinate cations.
In common SPEs, a polymer which has polar groups in the chain is necessary for electrolyte formation. Therefore, new materials with unconventional conduction mechanisms are clearly needed. Low ionic conductivity can be achieved from the fact that the ionic mobility strongly depends on the polymer segmental motion and that the cation transport number is low in the SPE at a high salt concentration. Thus, many researchers have focused on the SPE consisting of the polymer with low glass transition temperature and moderate concentrations of salt in order to overcome the low ionic conductivity of SPE, but high ambient conductivity has not yet been reached. However, it has a major drawback of having a low ionic conductivity (10 -8 to 10 -5 Scm -1) at room temperature. Most of the efforts to date have focused on poly(ethylene oxide) as the host material for SPE.
#AL2O3 GAUSSIAN SOFTWARE PORTABLE#
It was revealed that PS-Al 2O 3 composite solid polymer electrolyte containing 70 wt.% salt and 10 wt.% acidic Al 2O 3 showed the highest ionic conductivity of 9.78 × 10 -5 Scm -1 at room temperature.Ī lithium secondary battery using solid polymer electrolyte is an attractive energy source for portable devices since the use of SPE makes the fabrication of safe batteries possible and permits the development of thin batteries with design flexibility.
#AL2O3 GAUSSIAN SOFTWARE FREE#
Notably, the maximum enhancement of ionic conductivity is found in acidic Al 2O 3 compared with neutral and basic Al 2O 3 arising from the increase of free ion fraction by dissociation of salt. Moreover, Al 2O 3 can dissolve salt, instead of polar groups of polymer matrix, by the Lewis acid-base interactions between the surface group of Al 2O 3 and salt. However, in this PS-based composite polymer-in-salt system, the transport of cations is not by segmental motion but by ion-hopping through a lithium percolation path made of high content lithium salt. Based on the above point of view, polystyrene that has nonpolar groups is not suitable for the polymer matrix. In a common salt-in-polymer electrolyte, a polymer which has polar groups in the molecular chain is necessary because the polar groups dissolve lithium salt and coordinate cations.
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