Gaseous-phase, silica-coated sulfur particles as a cathode material for high-performance lithium/sulfur batteries

Lithium/sulfur (Li/S) batteries are one of the rechargeable batteries with high theoretical special capacity and high theoretical energy density. The gaseous-phase, silica (GPSiO(2))-coated sulfur composites with different weight ratios were synthesized through solid-state fusion method as a novel cathode material for Li/S batteries. X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and electrochemical testing methods were conducted to investigate the effect of gaseous-phase silica/sulfur composites on electrochemical performance. Results indicate that the composites have flocculent structure. The initial specific capacity of the GPSiO(2)/S-3:7 composite is up to 1610 mA h g(-1) at 0.1 C, which is the highest in the different ratio composites and is approximately 96% of sulfur utilization. The specific capacity was maintained at 814 mA h g(-1) after the 50th cycle. The GPSiO(2)/S-3:7 composite has the lowest impedance.