N-doped carbon interwoven with carbon nanotubes as an accelerating polysulfide conversion interlayer for High-Performance lithium-sulfur batteries

Abstract

Lithium-sulfur batteries (LSBs) are considered ideal for large-scale energy storage because of their high energy density and low cost, but it is necessary to solve their serious shuttle effects. In this paper, the melamine-formed nitrogen-doped carbon (NC) material is blended with carbon nanotubes (CNTs) to eventually form the composite material NC/CNT, which is coated on the separator to inhibit shuttle effects. The intertwined structure of NC/CNT forms a continuous conductive network, providing a fast transmission channel for Li+/e-. Additionally, NC/CNT effectively enhances the redox reaction kinetics and inhibits the shuttle effect of lithium polysulfides. Consequently, the cells incorporating NC/CNT exhibit excellent electrochemical performance, boasting a high reversible capacity of 611.5 mAh/g at 2C after 400 cycles, with a capacity decay rate of only 0.07%. These results underscore the considerable potential of the modified material for practical applications.