We demonstrate an importance of the effective separation between the sulphur cathode and the lithium anode in Li-S batteries. Improved cycling stability was obtained by using fluoro functionalized reduced graphene oxide (rGO) between the sulphur cathode and the lithium anode. The thickness of hydrophobic interlayer was found to be 1-2 micro meter. The possible mechanism checked with analytical techniques suggested that improvement in the capacity stability was attributed to the reduced reactivity of long chain polysulphides with the metallic lithium and to the homogenous distribution of end discharge products during cycling.
COBISS.SI-ID: 5504794
Understanding the mechanism(s) of polysulfide formation along with knowledge about the interactions of sulphur and polysulphides with a host matrix and electrolyte are essential for the development of long cycle life lithium sulphur (Li-S) batteries. To achieve this goal, new analytical tools need to be developed. In this work we report about the sulphur K-edge XANES study and 6,7Li MAS NMR study on a Li-S battery and its sulphur components. The setup for in operando XANES measurements can be viewed as a valuable analytical tool that can aid in the understanding of the sulphur environment in Li-S batteries. Complementary information about the lithium species within the cathode were obtained by 7Li MAS NMR spectroscopy.
COBISS.SI-ID: 3284475
The paper discuss the difference in the diffusion of polysulphides in two different electrolytes used for Li-S batteries. This is one of pioneering works on the field of electrolytes which undoubtedly show the importance of electrolyte choice for long term operation of Li-S batteries. Work published in this paper is a continuation of work published in the same journal in 2013.
COBISS.SI-ID: 5536794