M-N-Doped Carbon Nanofibers Modified Separators for Lithium-Sulfur Batteries

Abstract

A novel lightweight, multi-functional layer comprised of 1D porous metal-embedded nitrogen-doped carbon nanofibers (M-N-C) and 2D graphene sheets is introduced to modify a commercial polyolefin separator for using in lithium-sulfur batteries. Benefiting from the high electrical conductivity and strong lithium polysulfides (LiPSs) chemical adsorption ability of M-N-C, the porous intercalation-structured modified layer exhibits excellent ability to suppress LiPSs shuttling while maintaining high lithium-ion transport, and the modified layer functions as a highly conductive upper current collector to reutilize active sulfur species. The cell assembled with the modified multifunctional separator shows a high rate capability and excellent cycling stability. These exciting results indicate that this multifunctional membrane could be a promising separator candidate for Li-S batteries.