A dual-regulation strategy of B/N codoped CNT-encapsulated Ni nanoparticles as a catalytic host and separator coating promises high-performance Li-S batteries

A dual-regulation strategy of adopting B/N codoped carbon nanotube-encapsulated nickel nanoparticles (Ni@BNCNT) as a sulfur host and separator coating is proposed for high-performance Li-S batteries. On the cathode side, the 3D conductive network structure of Ni@BNCNT is favorable for high sulfur utilization, and the collaboration between polar metal Ni nanoparticles (NPs) and doped B/N elements facilitates the chemical adsorption of Li polysulfides (LiPSs). In addition, these metal Ni NPs exhibit a satisfactory catalytic effect on the polysulfide conversion. Moreover, using the Ni@BNCNT interlayer can further capture the soluble LiPSs, make them convert quickly, and prevent them from diffusing toward the anode side. The Li-S batteries simultaneously equipped with a S/Ni@BNCNT cathode and Ni@BNCNT interlayer show high reversible capacity and good cycle stability. Additionally, even at a sulfur loading of 3.5 mg cm −2 and an electrolyte/sulfur ratio of 3 μL mg −1 , excellent battery performance can be achieved. We believe that this work offers a new strategy based on combining a catalytic host and separator coating to construct high efficiency Li S batteries.