▎ 摘　　要

Nickel sulfides are regarded as one of the promising anode materials for sodium-ion batteries (SIBs), but the sluggish electrodes kinetics and rapid capacity decay, caused by their intrinsic low electrical conductivity and high bulk expansion, greatly limit their practical application. To overcome these obstacles, nano-sized, selenium-doped, nickel sulfide particles, anchored on nitrogen-doped reduced graphene oxide composites (NiS1-xSex@N-rGO), are rationally synthesized. The broad Na+ diffusion channels, resulting from Se doping, as well as the short Na+ transferring path, attributed from nano-size scale of NiS1-xSex particles, endow NiS1-xSex@N-rGO composites with ultrafast storage kinetics. Moreover, strong coupled effect between the NiS1-xSex and N-rGO is beneficial to the uniform dispersion of NiS1-xSex nanoparticles, improving electrical conductivity and suppressing the volume variation in charge/discharge process. Furthermore, the cut-off discharge voltage is modulated to realize the smaller volume change during cycle process. As a result, the fabricated anode of SIBs based on NiS1-xSex@N-rGO composites exhibits a high specific capacity of 300 mAh g(-1), at the current density of 1 A g(-1), after 1000 cycles with almost no capacity degradation.