In situ N-doped carbon nanotubes modified NiS2 hierarchical hollow microspheres for boosting sodium storage performance

Abstract

Engineering novel electrode materials with distinctive architectures has a significant influence on tuning the structural/electrochemical properties for boosting the sodium storage performance. Herein, starting from metal-organic framework (MOF), we report an in situ catalytic method with chemical transformation strategy to fabricate NiS2 hierarchical hollow microspheres (HMs) with continuous N-doped carbon nanotubes (NCNTs) networks (NiS2@NCNTs HMs). Benefitting from the hierarchical hollow structure and three-dimensional (3D) NCNTs networks as well as the robust structural stability, the prepared NiS2@NCNTs HMs indicates excellent Na+ storage performance. More specifically, the composite shows a high reversible capacity of 626.6 mA h g−1 at 0.2 A g−1 for Na+ storage and retains 333.3 mA h g−1 at 5.0 A g−1, remarkably higher than those of the previously reported NiS2-based anode materials. In particular, it maintains a stable reversible capacity of 343.0 mA h g−1 even at 3.0 A g−1 over 3000 cycles. The in situ catalytic NCNTs on MOF precursors strategy for hierarchical structural composites can be extended to other novel electrodes for high performance energy storage devices.