Performance of lithium sulfur batteries using multiwalled carbon nanotube paper as cathode current collector

In order to improve the cycle performance of lithium sulfur battery, the multiwalled carbon nanotubes (MWCNTs) paper were prepared by vacuum filtration method using paper fibers as the matrix and MWCNTs as the conductive additive. The MWCNTs paper was applied as the cathode current collector for lithium sulfur battery instead of aluminum foil. The morphology structure were characterized by SEM and the electrochemical properties were tested by the cell tester, and the EDS element analysis for the MWCNTs paper and sulfur composite cathode after cycles were also performed. The results show that MWCNTs are uniformly adhered to the paper fiber, and the porous MWCNTs paper has obviously 3D structure. The electrochemical tests indicate that the lithium sulfur battery with MWCNTs paper as current collector hold a specific capacity of 615 mAh/g and 496 mAh/g after 30 cycles in the current rate of 0.05 C and 1 C, respectively. The Coulombic efficiency maintains as high as 97.5%, and the charge transfer resistance decrease after cycles. The EDS element analysis verifies that the MWCNTs paper has adsorption role for the lithium polysulfides. The shuttle effect is restrained in some degree by the MWCNTs paper. As a result, MWCNTs paper used as the current collector can increase the sulfur loading capacity and contact area significantly, and improve the cycle stability and the Coulombic efficiency of lithium-sulfur battery.