Large-scale Ni-MOF derived Ni3S2 nanocrystals embedded in N-doped porous carbon nanoparticles for high-rate Na+ storage

Metal organic framework (MOF) has been confirmed as the promising precursor to develop the conversion-typed anode materials of sodium-ion batteries (SIBs) because of the tunable structure design and simple functional modification. Here, we prepare the ultrasmall Ni3S2 nanocrystals embedded into N-doped porous carbon nanoparticles using the scalable Ni-MOF as precursor (denoted as Ni3S2@NPC). The ultrasmall size of Ni3S2 can work for accelerated electron/ion transfer to facilitate the electrochemical reaction kinetics. Moreover, the robust conductivity network originated from N-doped porous carbon nanoparticles can not only improve the electron conductivity, but also enhance the electrode integrity and stability of the electrode/electrolyte interface. In addition, the N heteroatoms provide extra Na storage sites. Accordingly, the electrode delivers the obviously competitive capacities and high-power output with respect to the currently reported Ni3S2/C composites. This study provides a scalable and universal strategy to develop the advanced transition metal sulfides for practically feasible SIBs.