Enhanced performance of Li-S battery with polymer doped potassium functionalized graphene interlayers as effective polysulfide barrier

Abstract

In this study, the electrochemical performances of the novel glass fiber separators coated with potassium functionalized graphene (K-FGF) doped with polyaniline (PANI), poly 1,5-diaminoanthraquinone (PDAAQ) and PDAAQ/multi wall carbon nanotubes (MWCNT)/cetyltrimethyl-ammonium-bromide (CTAB) were evaluated for their ability of polysulfide entrapment to improve the cycling stability and the capacity fading rate. The test results showed that K-FGF coated glass fiber separator doped with PDAAQ and PDAAQ/MWCNT/CTAB displayed incredible improvement in the electrochemical performance of the battery, with high initial capacity of 1346 and 1361 mAh g−1 and capacity retention of 804 and 968 mAh g−1 after 200 cycles respectively. It is evident that PDAAQ suppresses the polysulfides shuttle in the electrolyte and offers a strong binding energy for the adsorption of polysulfides on the separator surface.