Preparation and lithium storage properties of active carbon-CNT/sulfur composite

Activated carbon was prepared with active carbon and carbon nanotubes (CNTs) as carriers of sulfur lithium-sulfur battery anode. The preparation was performed by sealing and heating molten lithium-sulfur batteries with different ratios of CNT, which was the positive active material. X-ray diffraction (XRD) pattern showed that composite material had more amorphous structure; the sample of C/CNT ratio of 3:1 exhibited the strongest amorphous, indicating that elemental sulfur was scattered into the pores of the carbon materials. Scanning electron microscopy showed that CNT was evenly dispersed into the activated carbon/sulfur composite materials in the anode material, forming a 3D conductive structure. The discharge specific capacity of the composite test exhibited that a small amount of CNT improved the discharge specific capacity of the anode material to active material for the preparation of activated carbon. The discharge specific capacity of CNT with 2:2 ratio was up to 1371.1 mAh/g. After the first 50 cycles, the discharge specific capacity could be stabilized at 687.3 mAh/g.