Electrospun CuCoN coating necklace-like N-doped carbon nanofibers for high performance lithium-sulfur batteries.

Freestanding electrodes with high energy density and cycle stability have attracted attention on the development of lithium-sulfur (Li-S) batteries. However, both severe shuttle effect and sluggish conversion kinetics hinder their practical applications. Herein, we employed the electrospinning and subsequent nitridation processes to prepare a necklace-like structure of CuCoN nanoparticles anchored on N-doped carbon nanofibers (CuCoN/NC) as freestanding sulfur host for Li-S batteries. Such bimetallic nitride boosts chemical adsorption and catalytic activity throughout detailed theoretical calculation and experimental electrochemical characterization. The three-dimensional conductive necklace-like framework could provide abundant cavities for realizing high sulfur utilization and alleviating the volume variation, as well as fast lithium-ions diffusion and electron transfer. The Li-S cell with the S@CuCoN/NC cathode delivers a stable cycling performance with a capacity attenuation rate of 0.076% per cycle after 150cycles at 2.0C and an exceptional capacity retention of 657 mAh g even at a high sulfur loading of 6.8 mg cm over 100cycles. The facile and scalable method can help promote the widespread application of fabrics.