Bieker Georg, Wellmann Julia, Kolek Martin, Jalkanen Kirsi, Winter Martin, Bieker Peter
MEET Battery Research Centre, Institute of Physical Chemistry, University of Münster, Corrensstrasse 28/30, 48149 Münster, Germany.
Phys Chem Chem Phys. 2017 May 10;19(18):11152-11162. doi: 10.1039/c7cp01238a.
In order to gain a deeper understanding of Li and Mg polysulphides in Li/S and Mg/S batteries, respectively, this work investigates the impact of the two different cations as well as the influence of the electrolyte solvents' relative dielectric permittivity and Gutmann's donor number on the solubility and relative stability of different Li and Mg polysulphide species. Therefore, the disproportionation and dissociation equilibria of chemically prepared "LiS" and "MgS" solutions in DMSO, DMF, ACN, THF, DME, TEGDME, and PyrTFSI are characterized by UV/Vis spectroscopy. Varying the cation and the solvent reveals their mutual interplay in stabilizing different polysulphide species. To our knowledge, this is the first time that chemically synthesized Mg polysulphides in solutions are studied. The results of this work provide essential knowledge for further development of the economically, ecologically, and also in terms of energy density and safety, attractive Mg/S batteries.
为了分别更深入地了解锂硫电池和镁硫电池中的锂多硫化物和镁多硫化物，本研究调查了两种不同阳离子的影响，以及电解质溶剂的相对介电常数和古特曼给体数对不同锂和镁多硫化物物种的溶解度和相对稳定性的影响。因此，通过紫外可见光谱对化学制备的“LiS”和“MgS”溶液在二甲基亚砜（DMSO）、二甲基甲酰胺（DMF）、乙腈（ACN）、四氢呋喃（THF）、1,2 - 二甲氧基乙烷（DME）、三乙二醇二甲醚（TEGDME）和双（三氟甲基磺酰）亚胺吡啶盐（PyrTFSI）中的歧化和解离平衡进行了表征。改变阳离子和溶剂揭示了它们在稳定不同多硫化物物种方面的相互作用。据我们所知，这是首次对溶液中化学合成的镁多硫化物进行研究。这项工作的结果为经济、生态以及在能量密度和安全性方面具有吸引力的镁硫电池的进一步发展提供了重要知识。
