TY  - JOUR
AU  - Bieker, Georg
AU  - Diddens, Diddo
AU  - Kolek, Martin
AU  - Borodin, Oleg
AU  - Winter, Martin
AU  - Bieker, Peter
AU  - Jalkanen, Kirsi
TI  - Cation-Dependent Electrochemistry of Polysulfides in Lithium and Magnesium Electrolyte Solutions
JO  - The journal of physical chemistry  / C C, Nanomaterials and interfaces
VL  - 122
IS  - 38
SN  - 1932-7455
CY  - Washington, DC
PB  - Soc.66306
M1  - FZJ-2018-06711
SP  - 21770 - 21783
PY  - 2018
AB  - In Li/S and Mg/S batteries, the charge and discharge of the sulfur cathode proceeds through a cascade of bivalent Sx2– and radical Sy•– polysulfide intermediates. The presence of Li+ or Mg2+ cations in the electrolyte determines the type of intermediates and the overpotentials of their formation in a different manner. Based on systematic cyclic voltammetry (CV) and UV/vis investigations, this work reveals how the mutual interplay of the different cations, the electrolyte solvent, and the polysulfide anions is reflected in the electrochemical behavior of “Li2S8”/LiTFSI and “MgS8”/MgTFSI2 solutions with dimethyl sulfoxide, dimethylformamide, acetonitrile, dimethoxyethane, tetraethylene glycol dimethyl ether, or tetrahydrofuran as solvent. It was observed that the disproportionation reactions of the polysulfides are generally more pronounced and especially the S3•– radical is less stabilized in Mg2+ than in Li+ containing solutions. In contrast to their Li counterparts, the formation of S42– polysulfides during the reduction of sulfur is not observed in glyme-based Mg polysulfide solutions. Quantum chemical predictions of stability and disproportionation of the Mg/polysulfide/solvent clusters complemented the CV and UV/vis investigations.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000446141900009
DO  - DOI:10.1021/acs.jpcc.8b06560
UR  - https://juser.fz-juelich.de/record/857743
ER  -