Highly dispersed sulfur in ordered mesoporous carbon sphere as a composite cathode for rechargeable polymer Li/S battery

A mesoporous carbon sphere with the uniform channels (OMC) is employed as the conductive matrix in the sulfur cathode for the lithium sulfur battery based on all-solid-state PEO18Li(CF3SO2)2N–10 wt%SiO2 electrolyte. Cyclic voltammograms (CV) and electrochemical impedance spectrum (EIS) suggest that the electrochemical stability of the S-OMCs is obviously superior to the pristine sulfur cathode. The S-OMCs composite shows excellent cycling performance with a reversible discharge capacity of about 800 mAh g−1 after 25 cycles. This would be attributed to an appropriate conductive structure in which the active sulfur is highly dispersed in and contacted with the OMCs matrix.

Research highlights▶ An ordered mesoporous carbon sphere (OMC) is employed as the conductive agent. ▶ Sulfur penetrates into the channels of the OMCs homogenously. ▶ The polysulfides are restricted from dissolving into the electrolyte. ▶ Cycling performance of the lithium sulfur battery is improved.