MnO 2 Nanosheets Grown on the Internal/External Surface of N-doped Hollow Porous Carbon Nanospheres as the Sulfur Host of Advanced Lithium-Sulfur Batteries

Abstract Nanostructured porous carbon materials are widely used as sulfur host materials in order to enhance sulfur utilization and improve electrical performance in Li-S batteries. However, owing to interface incompatibility between the nanocarbon with homogeneous nonpolar surface and intrinsic polar sulfur guests, the cathode materials still face poor stability during the long-term cycling process. Herein, based on a highly effective sulfur host, namely manganese oxide nanosheets grown on both sides of the N-doped hollow porous carbon nanospheres (NHCSs@MnO 2 ), we put forward a rational physical and chemical dual-encapsulation strategy for the application of advanced Li-S batteries. The multifunctional, integrated and hollow hybrid nanospheres can provide efficient electron-modified interface, hold much more active material, and importantly face-to-face effectively prevent polysulfide dissolution and diffusion via the synergistic restriction, thus the developed NHCSs@MnO 2 /S composite exhibits an initial discharge capacity of 1249 mAh g −1 at 0.5 C and a sustainable cycling stability with ultralow capacity decay of only 0.041% per cycle over 1000 cycles, implying its great prospects for the improved cyclability and electrochemical performance as application of advanced Li-S battery.