Cobalt nanoparticles & nitrogen-doped carbon nanotubes@hollow carbon with high catalytic ability for high-performance lithium sulfur batteries

Lithium-sulfur (Li-S) battery has been considered as a potential next-era energy storage device. However, its practical application is limited by the volume change of sulfur and the shuttle effect of lithium polysulfides. To effectively overcome these issues, a hollow carbon decorated with cobalt nanoparticles and interconnected by nitrogen doped carbon nanotubes (Co-NCNT@HC) is developed for high-performance Li-S battery. The uniformly distributed nitrogen and cobalt nanoparticles in Co-NCNT@HC are able to enhance the chemical adsorption capability and fasten the transformation speed of the intermediates, thus effectively inhibit the loss of lithium polysulfides. Moreover, the hollow carbon spheres interconnected by carbon nanotubes are structurally stable and electrically conductive. Due to the unique structure, the Li-S battery enhanced by Co-NCNT@HC shows a high initial capacity of 1550 mAh/g at 0.1 A g- 1. Even at a high current density of 2.0 A g-1, after 1000 cycles, it still maintains a capacity of 750 mAh/g with a capacity retention of 76.4% (the capacity decay rate is only 0.037% per cycle). This study provides a promising strategy for the development of high-performance Li-S batteries.

Automated summary

A hollow carbon decorated with cobalt nanoparticles and interconnected by nitrogen doped carbon nanotubes (Co-NCNT@HC) is developed to address the issues of volume change of sulfur and shuttle effect of lithium polysulfides in Li-S battery. The uniformly distributed nitrogen and cobalt nanoparticles in Co-NCNT@HC enhance the chemical adsorption capability and speed of intermediates transformation, effectively inhibiting the loss of lithium polysulfides. The unique structure of hollow carbon spheres interconnected by carbon nanotubes provides structural stability and electrical conductivity. The Li-S battery enhanced by Co-NCNT@HC exhibits high initial capacity and excellent cyclic stability.