Microwave-assisted synthesis of the sandwich-like porous Al2O3/RGO nanosheets anchoring NiO nanocomposite as anode materials for lithium-ion batteries

Hybridizing nanostructured metal oxides with reduced graphene oxide (RGO) is highly appropriate for the improvement of electrochemical performance of lithium-ion batteries (LIBs). Herein, a NiAl-layered double hydroxide (LDH) is vertically grown on a RGO by the microwave-assisted method without any surfactant or template. The NiAl-LDH/RGO is used as precursor to synthesize sandwich-like porous Al2O3/RGO anchoring NiO nanocomposite (NiO-Al2O3/RGO) by subsequent calcination and etching process. Furthermore, doping Al2O3 can prevent active materials from agglomeration and generate porous structure in etching process. When used as anode materials for LIBs, the nanocomposite exhibits a high reversible capacity after 100 charge-discharge cycles at a current density of 100 mA g−1. Even at 500 mA g−1, a stable capacity as high as 704 mA h g−1 could be obtained. The enhanced lithium storage performance is mainly ascribed to the presence of the conductive RGO and Al2O3 buffer phase, which can relieve structural collapse and offer high conductivity.