Binary Sulfiphilic Nickel Boride on Boron‐Doped Graphene with Beneficial Interfacial Charge for Accelerated Li–S Dynamics

Abstract

AbstractThe “shuttle effect” and slow conversion kinetics of lithium polysulfides (LiPSs) are stumbling block for high‐energy‐density lithium–sulfur batteries (LSBs), which can be effectively evaded by advanced catalytic materials. Transition metal borides possess binary LiPSs interactions sites, aggrandizing the density of chemical anchoring sites. Herein, a novel core–shelled heterostructure consisting of nickel boride nanoparticles on boron‐doped graphene (Ni3B/BG), is synthesized through a graphene spontaneously couple derived spatially confined strategy. The integration of Li2S precipitation/dissociation experiments and density functional theory computations demonstrate that the favorable interfacial charge state between Ni3B and BG provides smooth electron/charge transport channel, which promotes the charge transfer between Li2S4‐Ni3B/BG and Li2S‐Ni3B/BG systems. Benefitting from these, the facilitated solid–liquid conversion kinetics of LiPSs and reduced energy barrier of Li2S decomposition are achieved. Consequently, the LSBs employed the Ni3B/BG modified PP separator deliver conspicuously improved electrochemical performances with excellent cycling stability (decay of 0.07% per cycle for 600 cycles at 2 C) and remarkable rate capability of 650 mAh g−1at 10 C. This study provides a facile strategy for transition metal borides and reveals the effect of heterostructure on catalytic and adsorption activity for LiPSs, offering a new viewpoint to apply boride in LSBs.