Three-Dimensional Carbon Networks Decorated with Co Nanocatalysts as Multifunctional Interlayers for a High-Performance Lithium–Sulfur Battery
Xiongbin Yang, Lei Wang, Shuyi Cao, Hongyu Wang, Wenjia Han, Guihua Liu
Abstract
The notorious shuttle effect and slow redox kinetics have hindered the practical application of lithium–sulfur batteries (LSBs). To address these issues, a three-dimensional carbon network decorated with highly active nanocatalyst design is proposed as a multifunctional interlayer 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-situ catalytic growth of carbon nanotubes (CNTs) is introduced, leading to 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 highly active catalytic tentacles towards promoted LiPS trapping and conversion. As a result, the cell with Co/CNT@rGO-CF interlayer achieves a high capacity of 821.7 mA h g –1 after 500 cycles at 1 C with a capacity decay of 0.029% per cycle. At a high current density of 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 mA h cm –1 . This design of this unique interlayer structure is of great significance to suppress the shuttle effect of LiPS.