Preparation of graphene supported flower-like porous 3D ZnO-NiO ternary composites for high capacity anode materials for Li-ion batteries

Flower-like ZnO-NiO mesoporous architectures were synthesized through annealing the zinc hydroxide carbonate-nickel hydroxide carbonate composite precursor, which was prepared via a one-pot hydrothermal route. More importantly, we successfully prepared flower-like porous ZnO-NiO/graphene composites by introducing flexible graphene into the flower-like porous ZnO-NiO. In addition, we explore the application of the 3D flower-like ZnO-NiO composite mesoporous architectures and flower-like porous ZnO-NiO/graphene composites as anode materials for lithium ion battery. Electrochemical study presented that the as-prepared flower-like porous ZnO-NiO/graphene composites demonstrate excellent electrochemical performance and cycling stability. The first discharge capacity is 1205.7 mA h/g at a high current density of 300 mA/g. After 50 cycles, the reversible capacity is 452.7 mA h/g at a current density of 300 mA/g and the coulomb efficiency reaches at 99%.The improved electrochemical performances are mainly attributed to its morphological characteristics of mesoporous, nanosheet self-assembling architectures, as well as the addition of graphene. These results suggest that such 3D flower-like porous ZnO-NiO/graphene composites are promising materials for lithium ion battery.