Microwave-induced in situ synthesis of Zn_2GeO _4/N-doped graphene nanocomposites and their lithium-storage properties

摘要

Zn_2GeO_4/N-doped graphene nanocomposites have been synthesized through a fast microwave-assisted route on a large scale. The resulting nanohybrids are comprised of Zn_2GeO_4 nanorods that are well-embedded in N-doped graphene sheets by in situ reducing and doping. Importantly, the N-doped graphene sheets serve as elastic networks to disperse and electrically wire together the Zn_2GeO_4 the volume-expansion/contraction and aggregation of the nanoparticles during charge and discharge processes. We demonstrate that an electrode that is made of the as-formed Zn_2GeO_4/Ndoped graphene nanocomposite exhibits high capacity (1463 mAhg~(-1) at a current density of 100 mAg~(-1)), good cyclability, and excellent rate capability (531 mAhg~(-1) at a current density of 3200 mAg~(-1)). Its superior lithium-storage performance could be related to a synergistic effect of the unique nanostructured hybrid, in which the Zn_2GeO_4 nanorods are well-stabilized by the high electronic conduction and flexibility of N-doped graphene sheets. This work offers an effective strategy for the fabrication of functionalized ternary-oxide-based composites as high-performance electrode materials that involve structural conversion and transformation.