A novel three-dimensional sulfur/graphene/carbon nanotube composite prepared by a hydrothermal co-assembling route as binder-free cathode for lithium-sulfur batteries

摘要

A novel sulfur/graphene/carbon nanotube (S/GN/CNT) composite was successfully prepared by a facile hydrothermal co-assembling route. When used as cathode for lithium-sulfur battery, the S/GN/CNT composite can be pressed directly onto nickel foam without binder and conductive additive, thereby simplifying the manufacturing process. The resulting S/GN/CNT composite exhibited high and stable-specific discharge capacities of 670 mAh g(-1) after 80 cycles at 0.2 C and good rate capability. This enhanced electrochemical performance could be attributed to the combinative effects of GN and CNT, which not only function as a flexible conductive matrix, favoring the ion transport and electrolyte diffusion, but also for provide a porous three-dimensional architecture with open channels to effectively confine the soluble polysulfides.