S. Risse, E. Härk, B. Kent
Aug 23, 2019
Citations
0
Influential Citations
34
Citations
Journal
ACS nano
Abstract
This study reports the use of operando small angle neutron scattering to investigate processes in an operating Li/S battery. The combination with impedance spectroscopy yields valuable insights into the precipitation and dissolution of lithium sulfide during ten cycles of galvanostatic cycling. The use of deuterated electrolyte increases strongly the sensitivity to detect the sulfur and Li2S precipitates at the carbon host electrode and allows us to observe the time dependent initial wetting of the system. No correlation of the scattering signal of the micropores with neither lithium sulfide nor sulfur are observable during the whole course of the experiment. Hence both reaction products do not precipitate inside of the microporous structure though on the outer surface of the micrometre sized carbon fibres used in this study. The excellent scattering contrast allows a detailed analysis of the formation and dissoulution process of nanoscopic Li2S structures. While lithium sulfide particles grow homogeneously during the precipitation period, smaller Li2S particles dissolve first followed by a sudden dissolution of the larger Li2S particles.