Accelerating electrochemical reactions in Li-S batteries through better dispersion of sulfur and the robust catalytic effect upon the vanadium nitride decorated hollow carbon spheres

Li-S battery has been regarded as one of the most promising energy storage technologies due to the remarkable increase in energy density and desirable low cost when comparing with the commercial lithium-ion battery, yet the shuttling effect of soluble lithium polysulfide (LiPS) and the sluggish reaction kinetics during the reactions have hampered its further development. Here, we develop the vanadium nitride-decorated hollow carbon sphere (VNHCS) as advantageous sulfur host aiming to address these issues. Preferential distribution of nano sulfur around the layer region of VNHCS rather than aggregating into particles within the core is demonstrated as a result of the desirable chemical bonding effect of VN nanoparticles, which helps boost the electron and ion transport rates and inhibit shuttling of LiPS simultaneously. Furthermore, the accelerated reaction kinetics towards LiPS conversion are demonstrated by the favorable catalytic behavior of VNHCS, which are verified by the theoretical simulation results. Benefiting from these merits, the [email protected] cathode has exhibited advantageous electrochemical performances including the high initial discharge capacity of 1453 mA h g−1 at 0.1C and the ultralow capacity fading rate of 0.0293 % per cycle at 2C, outperforming most of the reported results of nitride compound-based sulfur cathodes.