Solution exchange method for synthesis of sulfur graphene composite

摘要

The Li-S battery system has been intensely concerned for over two decades for its high gravimetric capacity and energy density. Herein, we report a novel sulfur-graphene composite fabricated by solution exchange method with structure of sulfur uniformly dispersed on the graphene surface or filled in layer space of interwoven graphene sheets. The conductive and high specific surface area of single layer graphene sheets affords essential electrical contact to the insulating sulfur. As a result, a reversible capacity up to about 1200mAh/g can be achieved at the current density of 100mA/g and with the increase of current density to 1A/g, the remained capacity can attain 750mAh/g in 80 cycles.