Nano-size NiS particles anchored on nitrogen-doped reduced graphene oxide for superior sodium storage

Abstract

Nickel sulfides are regarded as promising anode materials for sodium-ion battery due to their natural abundance and high theoretical capacity. However, they are subjected to poor conductivity and severe volume variation during charging/discharging process, leading to sluggish kinetics and rapid capacity loss. To address these dilemmas, a hybrid composite consisting of nickel sulfide nanoparticles uniformly anchored on the nitrogen-doped reduced graphene oxide (NiS@N-rGO) has been fabricated through a facile sulfidation of ultrathin Ni(OH)2/rGO precursor. Owing to the high electronic conductivity of composite, alleviated volume expansion and accelerated ion diffusion, the NiS@N-rGO composite exhibits an initial specific capacity as high as 872.8 mAh g−1 at a current density of 0.2 A g−1 and maintain 300 mAh g−1 at a current density of 1 A g−1 after 300 cycles when employed as anode in sodium-ion batteries (SIBs). This work may present a new avenue in the design of electrode materials with excellent performance for SIBs in the future.