Porous 3D nitrogen-doped rGO/Co-Ni-S composite modified separator for high-capacity and stable lithium-sulfur batteries

A porous composite material consisted of nitrogen-doped 3D reduced graphene oxide and evenly distributed cobalt-nickel-sulfur (CNS) nanoparticles was coated on the surface of separator serving as the interlayer between separator and electrode in lithium-sulfur battery. It delivered an initial discharge capacity of 1524 mAh g(-1) at 0.1 C and a discharge capacity of 610 mAh g(-1) at 8 C. The designed Li-S battery exhibited superior long-term stability. After 350 cycles tested at 1 C, it retained a capacity as high as 700 mAh g(-1). It revealed that the N-dopants and decorated CNS nanoparticles in the composite could provide active sites to adsorb soluble poly-sulfides and accelerate the conversion of polysulfides in redox reactions, respectively, thereby suppressing the shutter effect and improving the electrochemical performance of the Li-S battery. Our strategy is promising for preparing safe and long-cycle Li-S batteries.

Automated summary

The porous composite material consisting of nitrogen-doped 3D reduced graphene oxide and cobalt-nickel-sulfur nanoparticles showed promising results when used as an interlayer in lithium-sulfur batteries, providing improved performance and long-term stability.