An Alumina-Coated Fe3O4-Reduced Graphene Oxide Composite Electrode as a Stable Anode for Lithium-ion Battery

Fe3O4-reduced graphene oxide (rGO) composites have been synthesized via an ethylene glycol-mediated solvothermal-polyol method. The electrochemical performances of the as-prepared Fe3O4-rGO electrode and alumina (Al2O3) film coated Fe3O4-rGO electrode using atomic layer deposition (ALD) were investigated. The results indicated that the ALD coating of Al2O3 greatly improved the electrochemical properties (especially cycling stability) of Fe3O4-rGO composite electrode as an anode for lithium-ion battery (LIB), resulting in the increase of reversible capacity from 94.1 mA h g−1 to 717.4 mA h g−1 after 200 cycles. The Al2O3 films retain sufficiently integral to limit the excessive growth of the interfacial layer between Fe3O4 and electrolyte, which in turn improves the electrochemical kinetics at the electrode/electrolyte interface and maintains a relatively stable interfacial resistance during whole discharge/charge cycles. The results presented in this study pave a new way to improve the stability of nanostructured anodes for LIBs.