A layer-by-layer supramolecular structure for a sulfur cathode†
Ordered, supramolecular structures which aim at tailoring the surface properties of materials have been greatly influenced by the advent of the layer-by-layer (LBL) self-assembly techniques. Any material with bonding abilities (ionic or hydrogen bonds) and which is accessible by a solvent can be transformed by assembly into a multilayer by the LBL approach. Here we propose a nanostructured sulfur cathode with a truffle-like architecture which comprises a sulfur particle embedded with hollow carbon nanospheres and encapsulated with an ion-selective, flexible LBL nanomembrane decorated with conductive carbon. As a result of this hierarchical arrangement cathodes with a final loading of 65% sulfur can operate at a high rate of 2C (a 1C rate corresponds to a complete charge or discharge in 1 hour) for over 500 cycles with nearly 100% coulombic efficiency. These results indicate that this type of nanointerfacial engineering could also be a promising solution for the low electrical conductivity of other battery cathodes.