Synthesis of multiwalled carbon nanotube aqueous suspension with surfactant sodium dodecylbenzene sulfonate for lithium/sulfur rechargeable batteries

Abstract

Due to the hydrophobic nature of multiwalled carbon nanotube (MWNT), sodium dodecylbenzene sulfonate (SDBS) was adopted as a surfactant to synthesize a well-dispersed, homogeneous MWNT aqueous suspension. By simple stirring mixing of the resultant MWNT suspension with nano-sulfur aqueous suspension, a novel porous sulfur/ multiwalled carbon nanotube composite (S/MWNT) was synthesized. This preparation method based on the suspension mixing possesses the advantages of simplicity and low cost. Homogeneous dispersion and integration of MWNT in the composite results in a porous, highly conductive and mechanically flexible framework with enhanced electronic conductivity and ability to absorb the polysulfides into its porous structure. The cell with this S/MWNT composite cathode demonstrates a high reversibility, resulting in a stable reversible specific discharge capacity of 708mAhg-1 after 100 cycles at 0.1 C. Furthermore, the S/MWNT composite cathode with sulfur content of 62.5wt% exhibits a good rate capability with discharge capacities of 946, 780 and 516mAhg-1 at 0.5, 1 and 1.5 C, respectively.