Templating synthesis of Fe2O3 hollow spheres modified with Ag nanoparticles as superior anode for lithium ion batteries

摘要

Ag-Fe2O3 hollow spheres are synthesized by using Ag@C core-shell matrix as sacrificial templates. The morphologies and structures of the as-prepared samples are characterized by scanning electron microscopy, X-ray powder diffraction energy dispersive, transmission electron microscopy and high resolution transmission electron microscopy. In contrast to Fe2O3 hollow spheres, Ag-Fe2O3 hollow spheres exhibit much higher electrochemical performances. The Ag-Fe2O3 composites exhibit an initial discharge capacity of 1030.9 mA h g⁻¹ and retain a high capacity of 953.2 mA h g⁻¹ at a current density of 100 mA g⁻¹ after 200 cycles. Furthermore, Ag-Fe2O3 electrode can maintain a stable capacity of 678 mA h g⁻¹ at 1 A g⁻¹ after 250 cycles. Rate performance of Ag-Fe2O3 electrode exhibits a high capacity of 650.8 mA h g⁻¹ even at 5 A g⁻¹. These excellent performances can be attributed to the decoration of Ag particles which will enhance conductivity and accelerate electrochemical reaction kinetics. Moreover, the hollow structure and the constructing particles with nanosize will benefit to accommodate huge volume change and stabilize the structure.