Two steps synthesis of plum-shaped C@Ni/MnO nanofiber heterostructures for trapping and catalyzing polysulfides in lithium-sulfur batteries.

Both spherical MnO as adsorbent and Ni nanoparticles as catalyzer, with highly exposed contact surface area in the carbon nanofibers, are successfully synthesized via electrospinning technology combined with carbothermal reduction. Compared with typical electrospun carbon nanofiber composites, the as-prepared C@Ni/MnO composite fibers as interlayer enable MnO and Ni to contact fully with polysulfides rather than provide local contact surface. With the sulfur loading of 1.6 mg cm and the approximately 0.1 g composite fibers as interlayer, the cathode shows initial capacity of 687.36 mAh g at 0.5C and superior capacity retention of 70%. This simple technical route leads a way to prepare nanoparticles with highly exposed contact surfaces partially embedded in the carbon nanofibers, which can be applied in electrocatalysis.