Self-Templated Formation of Interlaced Carbon Nanotubes Threaded Hollow Co₃S₄ Nanoboxes for High-Rate and Heat-Resistant Lithium–Sulfur Batteries

Abstract

Lithium-sulfur batteries (Li-S) have attracted soaring attention due to the particularly high energy density for advanced energy storage system. However, the practical application of Li-S batteries still faces multiple challenges, including the shuttle effect of intermediate polysulfides, the low conductivity of sulfur and the large volume variation of sulfur cathode. To overcome these issues, here we reported a self-templated approach to prepare interconnected carbon nanotubes inserted/wired hollow Co₃S₄ nanoboxes (CNTs/Co₃S₄-NBs) as an efficient sulfur host material. Originating from the combination of three-dimensional CNT conductive network and polar Co₃S₄-NBs, the obtained hybrid nanocomposite of CNTs/Co₃S₄-NBs can offer ultrahigh charge transfer properties, and efficiently restrain polysulfides in hollow Co₃S₄-NBs via the synergistic effect of structural confinement and chemical bonding. Benefiting from the above advantages, the S@CNTs/Co₃S₄-NBs cathode shows a significantly improved electrochemical performance in terms of high reversible capacity, good rate performance, and long-term cyclability. More remarkably, even at an elevated temperature (50 °C), it still exhibits high capacity retention and good rate capacity.