Department of Chemistry, University of Wisconsin-Parkside, Kenosha, Wisconsin 53141, USA.
Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 93352, USA.
J Chem Phys. 2017 Oct 28;147(16):161709. doi: 10.1063/1.4991565.
Using our polarizable force-field models and employing classical rate theories of chemical reactions, we examine the ethylene carbonate (EC) exchange process between the first and second solvation shells around Li and the dissociation kinetics of ion pairs Li-[BF] and Li-[PF] in this solvent. We calculate the exchange rates using transition state theory and correct them with transmission coefficients computed by the reactive flux, Impey, Madden, and McDonald approaches, and Grote-Hynes theory. We found that the residence times of EC around Li ions varied from 60 to 450 ps, depending on the correction method used. We found that the relaxation times changed significantly from Li-[BF] to Li-[PF] ion pairs in EC. Our results also show that, in addition to affecting the free energy of dissociation in EC, the anion type also significantly influences the dissociation kinetics of ion pairing.
利用我们的极化力场模型，并采用化学反应的经典速率理论，我们研究了锂离子的第一和第二溶剂化壳层之间的碳酸乙烯酯（EC）交换过程，以及在该溶剂中锂离子对 Li-[BF]和 Li-[PF]的离解动力学。我们使用过渡态理论计算交换速率，并使用反应通量、Impey、Madden 和 McDonald 方法以及 Grote-Hynes 理论计算的传输系数对其进行修正。我们发现，EC 围绕锂离子的停留时间在 60 到 450 ps 之间变化，具体取决于所使用的修正方法。我们发现，在 EC 中，从 Li-[BF]到 Li-[PF]离子对的弛豫时间发生了显著变化。我们的结果还表明，除了影响 EC 中离解的自由能外，阴离子类型也显著影响离子对的离解动力学。
