Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, Kraków 30-387, Poland.
J Phys Chem B. 2021 Feb 4;125(4):1248-1258. doi: 10.1021/acs.jpcb.0c10622. Epub 2021 Jan 22.
Classical and ab initio molecular dynamics (MD) simulations have been performed for electrolytes based on LiTFSI and NaTFSI solutions in ethylene carbonate and its mono- and difluoro derivatives. Differences between electrolytes with Li or Na ions and the effect of fluorination on the structure and transport properties have been analyzed. The observed differences are related to the strength of Me-carbonate binding, which is weaker for the Na cation and/or fluorinated solvents. Infrared spectra have been computed from ab initio MD and density functional tight binding (DFTB) MD trajectories. The changes of vibrational frequencies have been related to the local structure of the electrolyte and to interactions between salt cations and solvent molecules. The frequency shifts obtained from the AIMD simulations agree with experimental data, whereas DFTB underestimates Na-carbonate interactions.
已针对基于 LiTFSI 和 NaTFSI 溶液的电解质进行了经典和从头分子动力学（MD）模拟，这些溶液存在于碳酸乙烯酯及其一氟和二氟衍生物中。分析了具有 Li 或 Na 离子的电解质之间的差异以及氟化对结构和输运性质的影响。观察到的差异与 Me-碳酸盐结合的强度有关，对于 Na 阳离子和/或氟化溶剂，其结合强度较弱。已从从头算 MD 和密度泛函紧束缚（DFTB）MD 轨迹计算了红外光谱。振动频率的变化与电解质的局部结构以及盐阳离子与溶剂分子之间的相互作用有关。从 AIMD 模拟获得的频率位移与实验数据一致，而 DFTB 低估了 Na-碳酸盐相互作用。
