A high-energy sulfur cathode in carbonate electrolyte by eliminating polysulfides via solid-phase lithium-sulfur transformation.

ABSTRACT: Carbonate-based electrolytes demonstrate safe and stable electrochemical performance in lithium-sulfur batteries. However, only a few types of sulfur cathodes with low loadings can be employed and the underlying electrochemical mechanism of lithium-sulfur batteries with carbonate-based electrolytes is not well understood. Here, we employ in operando X-ray absorption near edge spectroscopy to shed light on a solid-phase lithium-sulfur reaction mechanism in carbonate electrolyte systems in which sulfur directly transfers to Li₂S without the formation of linear polysulfides. Based on this, we demonstrate the cyclability of conventional cyclo-S₈ based sulfur cathodes in carbonate-based electrolyte across a wide temperature range, from -20?°C to 55?°C. Remarkably, the developed sulfur cathode architecture has high sulfur content (>65?wt%) with an areal loading of 4.0?mg?cm^-2. This research demonstrates promising performance of lithium-sulfur pouch cells in a carbonate-based electrolyte, indicating potential application in the future.

SUBMITTER: Li X 

PROVIDER: S-EPMC6207722 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature