The preparation of nano-sulfur/MWCNTs and its electrochemical performance

In this work, a novel nano-sulfur/MWCNTs composite with modified multi-wall carbon nano-tubes (MWCNTs) as sulfur-fixed matrix for Li/S battery is reported. Based on different solubility of sulfur in different solvents, nano-sulfur/MWCNTs composite was prepared by solvents exchange method. The composite was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The modified MWCNTs are considered that not only acts as a conducting material, but also a matrix for sulfur. The electrochemical performance of the nano-sulfur/MWCNTs composite was tested. The results indicated that nano-sulfur/MWCNTs composite had the specific capacity of 1380 mAh g ―1 , 1326 mAh g ―1 and 1210 mAh g ―1 in the initial cycle at 100 mA g ―1 , 200 mA g ―1 and 300 mAh g ―1 discharge rates respectively, and remained a reversible capacity of 1020 mAh g ―1 , 870 mAh g ―1 and 810 mAh g ―1 after 30 cycles. The electrochemical performances confirm that the modified MWCNTs as sulfur-fixed matrix show better ability than any other carbon in cathode of Li/S batteries that had been reported.