The in-situ-prepared micro/nanocomposite composed of Sb and reduced graphene oxide as superior anode for sodium-ion batteries

Metallic antimony (Sb) is one promising candidate as anode material for sodium-ion batteries (SIBs) due to its high theoretical capacity of 660 mAh/g. However, the electrochemical formation of Na3Sb alloy makes it will suffer from tremendous volume variation during Na-uptake/release cycling and hence poor practical Na-storage properties. The incorporation of reduced graphene oxide (rGO) should be one effective strategy to overcome this issue. Herein, it is excitingly discovered that in-situ preparation micro/nanocomposite composed of Sb and rGO has played an effective role on improving Na-storage performance, especially fast energy storage and cycle life. The in-situ-prepared micro/nanocomposite (I-Sb/rGO) can deliver a superior capacity of 112 mAh/g even at an ultrahigh current density of 6 A/g compared to the ex-situ-prepared one (E-Sb/rGO). And it also exhibits outstanding cycle life with a residual capacity of 173 mAh/g after 150 cycles at current density of 0.5 A/g, much higher than that (36 mAh/g) of the ex-situ one. Those enhanced performance can be attributed to the advanced in-situ-prepared process.