Dziubinska-Kühn Katarzyna, Maddah Mina, Pupier Marion, Matysik Jörg, Viger-Gravel Jasmine, Kowalska Magdalena, Karg Beatrice
CERN, Geneva, Switzerland.
Institute of Analytical Chemistry, University of Leipzig, Leipzig, Germany.
Front Chem. 2022 Nov 15;10:1028912. doi: 10.3389/fchem.2022.1028912. eCollection 2022.
The global need to expand the design of energy-storage devices led to the investigation of alkali metal - Ionic Liquid (IL) mixtures as a possible class of electrolytes. In this study, 1D and 2D Nuclear Magnetic Resonance (NMR) and Electrochemical Impedance Spectroscopy (EIS) as well as Molecular Dynamics (MD) simulations were used to study the intermolecular interactions in imidazolium-based IL - water - alkali halide ternary mixtures. The H and Na 1D and H DOSY NMR spectra revealed that the presence of small quantities of NaCl does not influence the aggregation of water molecules in the IL nano-domains. The order of adding ionic compounds to water, as well as the certain water and NaCl molecular ratios, lead to the formation of isolated water clusters. Two ternary solutions representing different orders of compounds mixing (HO+ IL + NaCl or HO+ NaCl + IL) showed a strong dependence of the initial solvation shell of Na and the self-clustering of water. Furthermore, the behaviour of water was found to be independent from the conditions applied during the solution preparation, such as temperature and/or duration of stirring and aging. These findings could be confirmed by large differences in the amount of ionic species, observed in the ternary solutions and depending on the order of mixing/solute preparation.
全球对扩展储能设备设计的需求促使人们对碱金属-离子液体（IL）混合物作为一类可能的电解质进行研究。在本研究中，采用一维和二维核磁共振（NMR）、电化学阻抗谱（EIS）以及分子动力学（MD）模拟来研究基于咪唑鎓的离子液体-水-碱金属卤化物三元混合物中的分子间相互作用。氢和钠的一维及氢扩散排序谱（DOSY）核磁共振谱表明，少量氯化钠的存在不会影响水分子在离子液体纳米域中的聚集。向水中添加离子化合物的顺序以及特定的水与氯化钠分子比例会导致孤立水簇的形成。两种代表不同化合物混合顺序（水+离子液体+氯化钠或水+氯化钠+离子液体）的三元溶液显示出钠的初始溶剂化层以及水的自聚集强烈依赖于此。此外，发现水的行为与溶液制备过程中所施加的条件无关，如温度和/或搅拌及老化持续时间。这些发现可通过在三元溶液中观察到的且取决于混合顺序/溶质制备的离子种类数量的巨大差异得到证实。
