Yamaguchi Tsuyoshi, Yonezawa Takuya, Yoshida Koji, Yamaguchi Toshio, Nagao Michihiro, Faraone Antonio, Seki Shiro
Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa, Nagoya, Aichi 464-8603, Japan.
Department of Chemistry, Faculty of Science, Fukuoka University , Nanakuma, Jonan, Fukuoka 814-0180, Japan.
J Phys Chem B. 2015 Dec 24;119(51):15675-82. doi: 10.1021/acs.jpcb.5b08701. Epub 2015 Dec 14.
The structure and dynamics of the solutions of LiPF6 in propylene carbonate over a concentration range of 0-3 mol/kg are studied with neutron spin echo spectroscopy, alternating-current (AC) conductometry, and shear impedance spectroscopy. The neutron diffraction shows a prepeak at ≈10 nm(-1) in addition to the main peak at ≈14 nm(-1) when the concentration of the salt is no less than 2 mol/kg. Compared with the frequency-dependent shear viscosity and AC conductivity, the relaxation of the shear stress agrees with that expected from the structural relaxation of the main peak. On the other hand, the relaxation of the conductivity is slower than the shear relaxation at all the concentrations, and the former approximately matches with the relaxation of the prepeak at the highest concentration, 3 mol/kg, which is several times slower than that of the main peak. The possible contribution of the prepeak structure to the ionic conduction is discussed.
利用中子自旋回波光谱、交流（AC）电导法和剪切阻抗光谱研究了碳酸丙烯酯中LiPF6在0 - 3 mol/kg浓度范围内溶液的结构和动力学。当盐浓度不低于2 mol/kg时，中子衍射除了在≈14 nm⁻¹处有主峰外，在≈10 nm⁻¹处还出现一个前峰。与频率相关的剪切粘度和AC电导率相比，剪切应力的弛豫与主峰结构弛豫预期的情况相符。另一方面，在所有浓度下，电导率的弛豫都比剪切弛豫慢，并且在最高浓度3 mol/kg时，前者大致与前峰的弛豫相匹配，比主峰的弛豫慢几倍。讨论了前峰结构对离子传导的可能贡献。
