Decoupling between the Temperature-Dependent Structural Relaxation and Shear Viscosity of Concentrated Lithium Electrolyte

作者:Yamaguchi Tsuyoshi; Yoshida Koji; Yamaguchi Toshio; Nagao Michihiro; Faraone Antonio; Seki Shiro
来源:Journal of Physical Chemistry B, 2017, 121(37): 8767-8773.
DOI:10.1021/acs.jpcb.7b04633

摘要

The intermediate scattering functions of concentrated solutions of LiPF6 in propylene carbonate (PC) were measured at various temperatures, two different wavenumbers, and three different concentrations using neutron spin echo (NSE) spectroscopy. The temperature dependence of the relaxation time was larger than that of the steady-state shear viscosity in all cases. The shear relaxation spectra were also determined at different temperatures. The normalized spectra reduced to a master curve when the frequency was multiplied by the steady-state shear-viscosity, indicating that the temperature dependence of the steady-state shear viscosity can be explained by that of the relaxation time of the shear stress. It is thus suggested that the dynamics of the shear stress is decoupled from the structural dynamics on the molecular scale.

  • 出版日期2017-9-21