Nanostructured Fe_3O_4@C as anode material for lithium-ion batteries

摘要

The active particle cracking and electrode pulverization of iron oxide anode material as a result of volume expansion during charge/discharge process cause poor reversibility and significant capacity fading in rechargeable lithium-ion batteries. Here, we demonstrate a facile solvothermal route to immobilize the Fe_3O_4 particles on the porous active carbon. The present method enables us to obtain nano-porous and mosaic structured Fe_3O_4@C spheres with an average size of ca 100 nm. The porous active carbon plays an important role in the improvement of electrochemical properties of Fe_3O_4. It not only acts as a host for the deposition of Fe_3O_4 particles, but also provides void spaces for active Fe_3O_4 to buffer the volume expansion. The good contact between Fe_3O_4 and active carbon ensures the fast electron/Li-ion transport. As a result, the porous Fe_3O_4@C shows a high reversible specific capacity of ~ 1000 mAh g~(-1), good cycle stability and excellent rate capability. Therefore, we believe that this composite is a potential candidate for anode material of high-energy lithium-ion battery.