Catalytic NiO/Ni/N-doped carbon nanoreactors for suppressing polysulfide shuttle: <i>In situ</i> Raman spectroscopic validation

Abstract

The practical implementation of lithium-sulfur batteries remains hindered by polysulfide shuttling and sluggish redox kinetics. To address this, we synthesize NiO/Ni nanoparticles anchored on nitrogen (N)-doped carbon hollow nanospheres (NiO/Ni-NCHN) via a sacrificial template strategy. This nanoreactor design synergistically combines physical confinement and catalytic mediation: the hollow N-doped carbon framework facilitates rapid electron/Li+ transport while accommodating high sulfur loading, whereas NiO/Ni nanoparticles provide strong chemical adsorption sites and catalyze Li2S decomposition/formation. Crucially, in situ Raman spectroscopy directly tracks polysulfide evolution, revealing accelerated reaction kinetics enabled by the catalyst. The NiO/Ni-NCHN/S cathode delivers exceptional cyclability, retaining 438 mAh g−1 after 500 cycles at 1 C with an ultralow decay rate of 0.089% per cycle. This work establishes a materials-design paradigm for high-energy-density batteries through integrated physicochemical confinement and spectroscopic mechanism validation.