Reduction mechanism of sulfur in lithium–sulfur battery: From elemental sulfur to polysulfide

A novel separator coated by carbon for achieving exceptional high performance lithium-sulfur batteries

“…The cathodic peak in the first cycle appears at 2.2V, which is probably due to the over potential of the electrode, caused by the morphology and position changes during the discharge. This cathodic peak shifts to a relatively stable value, 2.3 V, from the second cycle, which is due to the rearrangement of the migrating active material to electrochemically favorable positions [42][43][44]. The discharge/charge profiles in Figure 2b, exhibiting two discharge plateaus and two closely spaced charge plateaus, are consistent with the cyclic voltammogram plots.…”

Reaction between Lithium Anode and Polysulfide Ions in a Lithium–Sulfur Battery

“…The dissolved polysulfide ions could not be quantitatively or qualitatively analyzed until recently, when a high‐performance liquid chromatography (HPLC)– mass spectroscopy (MS) method was successfully introduced for the analysis of polysulfide and elemental sulfur in electrolytes of Li–S batteries . The polysulfide anions were first derivatized according to Reaction (2), the derivatized mixtures were separated by a HPLC, and the sulfur chain length of the derivatized polysulfide species was determined by the mass/charge ratio with a MS.…”

Quantitative Galvanostatic Intermittent Titration Technique for the Analysis of a Model System with Applications in Lithium−Sulfur Batteries

“…Impedance spectroscopy has also been used to evaluate the individual contributions from electrolyte resistance, charge transfer, ion diffusion and electrode surface layers, which in turn has been used to refine mechanistic models of Li−S cells,, as well as to investigate capacity fading . Other experimental techniques used to elucidate redox and diffusion properties in Li−S cells include XAS, in‐operando optical imaging of the temporal and spatial distribution of polysulfides, UV‐Vis spectroscopy, NMR, EPR/ESR,, XRD, Raman, HPLC, and gas evolution, among other electrochemical studies . The mechanism and kinetics of Li 2 S precipitation has been studied using chronoamperometry .…”