Freestanding sulfur-graphene oxide/carbon composite paper as a stable cathode for high performance lithium-sulfur batteries.

Abstract The structural design and synthesis of sulfur-carbon composite materials with high performance is still a major challenge for rechargeable lithium-sulfur batteries. Interconnected three-dimensional frameworks comprising multi-walled carbon nanotubes, graphene, or carbon particles offer a combination of constituent advantages and can thus be used to achieve superior energy conversion and storage properties. Herein, we designed and prepared free-standing three-dimensional sulfur papers containing interconnected highly conductive carbon materials, which enable to be flexible binder-free cathodes for Li-S batteries. The resultant sulfur-carbon composite paper cathode exhibited high reversible specific capacity of 1386 mAhg−1, good rate capability up to 5C, and excellent cycling performance (a capacity retention 68% after 400 cycles), all of which are significantly improved from those of bare sulfur cathode or sulfur-GO composite only. Rational design of cathode composition, structure, and a simple fabrication process can give insight into the development of various advanced cathode materials for high-performance Li-S batteries. Graphical abstract Image 1 Highlights • The composition of in-situ formed sulfur particles on the surface of GO with conductive carbons was designed and prepared. • Highly flexible and conductive S-GO/SP and S-GO/MWCNT papers were used the cathode for Li-S battery. • The use of composite papers allowed high reversible capacity and stable cycling performance. • The use of S-GO/MWCNT composite papers improved the rate capability. • The interconnected 3D framework was able to suppress the migration of polysulfides and irreversible agglomeration/deposition. [ABSTRACT FROM AUTHOR]