Figure 1 (a) The optical images and the structure of S8 and PhSeH, (b) long-cycling performance of Li-S cells for 100 cycles, the rate is 0.05 C in the first two cycles and 1 C in the subsequent cycles, and (c) voltage profiles of Li-S cells with the blank and PhSeH electrolytes.
Figure 2 (a) The cycling performance and (b) voltage profiles of coin cells with 0.70 M PhSeH and blank electrolytes at the rate of 0.5 C. (c) The rate performance of coin cell with 0.70 M PhSeH electrolyte. (d) Li-S cell with a sulfur mass loading of 2.1 mg and 0.70 M PhSeH electrolyte. (e) The cycling performance of the Li-S pouch cell with PhSeH electrolyte.
Figure 3 (a) The UV-Vis spectra of the discharged cathode at cut-off voltage of 2.1 V. (b-c) Mass spectra of the discharged sample. (d-f) Mass spectra of the recharged sample. (g)Se 3d XPS spectra of the discharged sample. (h-i) S 2p (h) and Se 3d (i) XPS spectra of the recharged sample
Figure 4 The in-situ Raman spectra of the discharge and charge process on the cathode and the corresponding illustration of the reaction mechanism: (a) the first discharge process and (b) the charge process.