Hydroxylated sandwich-structure interlayer as a polysulfide reservoir for lithium-sulfur battery

In order to achieve the practical application of lithium-sulfur batteries, the severe shuttle effect and self-discharge behavior of lithium-sulfur batteries needed to be checked. In this study, hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) and cellulose fibers were mixed and then were fabricated as the interlayer by paper-making process. The interlayer of hydroxylated multi-wall carbon nanotube and paper fibers were sandwiched between two PP separators to form the sandwich structure interlayer. The OH hydrophilic functional group formed on the carbon material can effectively trap polysulfides and inhibit the shuttling of polysulfides. At the same time, the MWCNTs-OH paper as the second collector effectively improved the utilization of active materials. The MWCNT-OH sandwich-structure interlayer effectively improved the performance of the lithium-sulfur battery. At 0.1 C rate, the initial discharge specific capacity reached 1532 mAh g−1. The capacity hold at 516 mAh g−1 after 500 cycles at 1C and only exhibited a capacity decay rate of 0.028% per cycle.