Three-Dimensional Carbon Networks Decorated with Co Nanocatalysts as Multifunctional Interlayers for a High-Performance Lithium-Sulfur Battery

The notorious shuttle effect and slow redox kineticshave hinderedthe practical application of lithium-sulfur batteries (LSBs).To address these issues, a three-dimensional carbon network decoratedwith highly active nanocatalyst design is proposed as a multifunctionalinterlayer in LSBs. In this design strategy, reduced graphite oxide(rGO) is infiltrated into the internal skeleton of the carbon fiber(CF) film. This forms a dense rGO-CF carbon substrate on which in-situcatalytic growth of carbon nanotubes (CNTs) is introduced, leadingto the formation of an interlayer decorated with Co nanocatalysts.The resulting Co/CNT@rGO-CF interlayer acts as a physical barrier,inhibiting the shuttling of lithium polysulfides (LiPS). In addition,CNTs are decorated with abundant Co nanoparticles, forming highlyactive catalytic tentacles towards promoted LiPS trapping and conversion.As a result, the cell with Co/CNT@rGO-CF interlayer achieves a highcapacity of 821.7 mA h g(-1) after 500 cycles at 1C with a capacity decay of 0.029% per cycle. At a high current densityof 5 C, a capacity of 700.6 mA h g(-1) is also obtained.Furthermore, even at the high sulfur loading of 6.7 mg cm(-2), the cell still has an excellent capacity performance of 5.23 mAh cm(-1). This design of this unique interlayer structureis of great significance to suppress the shuttle effect of LiPS.