Co nanoparticles-embedded hierarchical porous carbon network as high-performance cathode for lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) are one of the most promising electrochemical energy storage systems because of their great advantages in theoretical energy density. However, poor conductivities of sulfur and discharge products Li2S2 and Li2S, volume expansion during charge/discharge, and the shuttle effect of lithium polysulfides (LiPSs) severely limit the capacity and cycle performances of LSBs. In this study, a template method was used to prepare the Co nanoparticle-embedded N-doped hierarchical porous carbon network (Co-NHPC) with good adsorption and catalytic conversion ability of LiPSs. The results show that Co-NHPC provides a high initial specific capacity of 1478.6 mA h g−1 at 0.2 C. Even after 500 cycles, Co-NHPC maintains good reversible capacities of 674.9 and 451.6 mA h g−1 at 1 and 5 C, respectively.