SnO(2)-Graphene composite synthesized via an ultrafast and environmentally friendly microwave autoclave method and its use as a superior anode for lithium-ion batteries
SnO2–graphene composites have been synthesized by an ultrafast and environmentally friendly microwave autoclave method. From field emission scanning electron microscopy and transmission electron microscopy, it can be determined that the SnO2 nanoparticles, around 4–5 nm in diameter, are uniformly sandwiched between graphene nanosheets containing only a few layers. The successful synthesis demonstrates that in situ loading of SnO2 nanoparticles can be an effective way to prevent graphene nanosheets from being restacked during the reduction. The Li-cycling properties of the materials have been evaluated by galvanostatic discharge–charge cycling and impedance spectroscopy. Results show that the SnO2–graphene composite with a graphene content of 33.3 wt % exhibits a very stable capacity of about 590 mA h g–1 without noticeable fading for up to 200 cycles.