Ultrasmall metal oxide nanoparticles anchored on three-dimensional hierarchical porous gaphene-like networks as anode for high-performance lithium ion batteries

Abstract

A rational design of well-dispersed and high-level ultrasmall metal oxide (MOx, M=Sn or Fe) nanoparticles anchored on 3D hierarchical porous graphene-like (HPG) networks and fabrication via a simple hydrothermal process have been achieved for the first time. By taking the advantages of the 3D HPG composites like that the well-dispersed MOx nanoparticles in ultrasmall size with the high mass loadings (more than 70%) on conductive 3D HPG substrates provide abundant active sites for Li ion insertion and good conductivity and short diffusion length for Li ions, which are beneficial for high capacity and rate capability. Meanwhile, 3D HPG can hold the ultrasmall MOx nanoparticles tightly by the pores, which avoids serious volume change and agglomeration of the ultrasmall MOx nanoparticles caused by lithium insertion/extraction. This ensures the material high capacity and cycling stability. The as-prepared SnO2-3D HPG and Fe2O3-3D HPG electrodes exhibit high reversible capacity of 986mAhg−1 and 907mAhg−1 after 100 cycles at 100mAg−1, respectively. In addition, the two electrodes exhibit excellent cycling performance at various rates and superior rate performance at 10Ag−1 and a long lifetime of 1000 cycles with nearly 90% capacity retention. Such high performance is superior to those reported recently. It is a chance to extend this present synthesis method to prepare other electrode materials with high electron/Li ion transfer kinetics for practical and large-scale applications in electrochemical fields.