In-situ plantation of Fe3O4@C nanoparticles on reduced graphene oxide nanosheet as high-performance anode for lithium/sodium-ion batteries

Highlights: • Fe₃O₄@C nanoparticles are in situ grown on rGO to form a lamellar anode. • Fe₃O₄@C has an ultra-small particle size of ca. 12.5 nm. • The unique structure of Fe₃O₄@C/rGO can provide good electrochemical performance. • It shows 849 mA h g⁻¹ at 0.5 A g⁻¹ after 120 cycles in LIB. • It shows 429 mA h g⁻¹ at 0.1 A g⁻¹ after 300 cycles in SIB. Fe₃O₄ is considered to be an ideal substitute for graphite anode due to its high lithium (Li) and sodium (Na) storage capacity, however, its sharp volume change after lithiation/sodiumization and poor electrical conductivity have brought huge challenges to the practical application. In this study, a lamellar Fe₃O₄-based electrode was constructed via an in-situ plantation of carbon-coated Fe₃O₄ nanoparticles on the surface of the reduced graphene oxide nanosheet. Owing to the ultra-small carbon-coated Fe₃O₄ nanoparticles (~12.5 nm) and unique two-dimensional lamellar structure, the obtained sample displays excellent cycle and rate performance in lithium/sodium-ion batteries. A high reversible capacity of 849 mA h g⁻¹ is obtained at 500 mA g⁻¹ after 120 cycles for lithium-ion batteries and a discharge capacity up to 429 mA h g⁻¹ is remained at 100 mA g⁻¹ after 300 cycles for sodium-ion batteries.