Advances in Selenium Sulfides Cathodes for Lithium/Selenium–Sulfur Batteries

Optical and X-ray absorption interrogation of selenium-based redox in Li–SxSey batteries

“…[4][5][6] Another route to improving conductivity and electrode kinetics involves blending sulphur with a more electrically conductive chalcogen-selenium (Se)-(10 À4 S m À1 compared to 10 À14 S m À1 ) which displays similar electrochemical redox characteristics, albeit with lower theoretical capacity (678 mA h g À1 ). [7][8][9] Selenium exhibits better capacity retention than sulphur upon extended cycling, ascribed to the higher conductivity of the former and lower prevalence of polyselenide formation (versus analogous polysulfide). To harness the best characteristics of abundant sulphur and conductive, cyclable selenium, we use a glassy sulphur-selenium composite 10 as a vapor-deposition precursor in the fabrication of cathodes based on porous carbon nanofoam paper (CNFP) substrates, as recently demonstrated with sulphur-only deposition.…”