Anchored monodispersed silicon and sulfur nanoparticles on graphene for high-performance lithiated silicon-sulfur battery

Lithium-sulfur battery is one of the most potential high-performance electrochemical energy storage devices with widely applications, however, when using lithium metal as an anode a number of problems exist, including strong chemical activity with the organic electrolyte system and susceptibility to lithium dendrite formation during charge/discharge processes. Such effects can lead to undesired shorter lifespans and serious safety implications. Herein, we prepared monodispersed 0 D silicon and sulfur nanoparticles which are tightly anchored onto a 2D graphene nanosheet surface (M-Si-NP/GNs and M-S-NP/GNs). Importantly, we demonstrate that the electrochemical property is critically dependent on a combination of nanosize effects and dispersity. From these results a novel lithiated silicon-sulfur cell using lithiated M-Si-NP/GNs and M-S-NP/GNs as anode and cathode, respectively, was developed and tested. Remarkably, the lithiated silicon-sulfur cell displayed large specific capacity of 782 mA h g⁻¹ at 0.5 A g⁻¹. Based on the overall mass of active material on the anode and cathode, the ultra-high energy density of the full cell was 1447 W h kg⁻¹. Furthermore, a superior rate performance was observed and an outstanding cycle stability over 500 cycles at 0.5 A g⁻¹ (i.e. an ultraslow capacity loss per cycle was 0.018%) was maintained.