Large-scale synthesis of NiS@N and S co-doped carbon mesoporous tubule as high performance anode for lithium-ion battery

Abstract

The simple and large-scale synthesis of metal sulfides@heteroatom-doped carbon tubules with high lithium storage performance is seldom reported. In this work, mesoporous NiS@N and S co-doped carbon (NiS@NSC) tubules were firstly prepared by nickel salt impregnation and subsequently calcination using absorbent cotton as template. The crystalline NiS nanoparticles with an average particle size of about 90 nm are uniformly embedded in the mesoporous tubular N and S co-doped carbon skeleton. The BET specific surface area is 200.8 m2 g−1 and the uniform narrow mesopore size distributes centered at 2.32 nm. As anode for lithium-ion batteries, it displays good cycling stability and rate capability, which retains a reversible capacity of 715.9 mA h g−1 after 200 cycles at 0.1 A g−1, and even at a high current density of 5 A g−1 the specific discharge capacity can retain 411.1 mA h g−1, which is higher than for most of the reported NiS@C composites. The good electrochemical performances are mainly attributed to the inherent characteristics of NiS@NSC hollow tubules, involving uniform mesopores, large specific surface area and highly conductive N and S co-doped carbon skeleton.