Ultrathin MnO2/Graphene Oxide/Carbon Nanotube Interlayer as Efficient Polysulfide-Trapping Shield for High-Performance Li-S Batteries

Ultrathin MnO2/graphene oxide/carbon nanotube (G/M@CNT) interlayers are developed as efficient polysulfide-trapping shields for high-performance Li-S batteries. A simple layer-by-layer procedure is used to construct a sandwiched vein-membrane interlayer of thickness 2 mu m and areal density 0.104 mg cm(-2) by loading MnO2 nanoparticles and graphene oxide (GO) sheets on superaligned carbon nanotube films. The G/M@CNT interlayer provides a physical shield against both polysulfide shuttling and chemical adsorption of polysulfides by MnO2 nanoparticles and GO sheets. The synergetic effect of the G/M@CNT interlayer enables the production of Li-S cells with high sulfur loadings (60-80 wt%), a low capacity decay rate (-0.029% per cycle over 2500 cycles at 1 C), high rate performance (747 mA h g(-1) at a charge rate of 10 C), and a low self-discharge rate with high capacity retention (93.0% after 20 d rest). Electrochemical impedance spectroscopy, cyclic voltammetry, and scanning electron microscopy observations of the Li anodes after cycling confirm the polysulfide-trapping ability of the G/M@CNT interlayer and show its potential in developing high-performance Li-S batteries.