Nitrogen-doped carbon-coated Fe 3 O 4 /rGO nanocomposite anode material for enhanced initial coulombic efficiency of lithium-ion batteries

Nitrogen-doped carbon-coated Fe3O4/reduced graphite oxide (NC@Fe3O4/rGO) nanocomposites with in situ polymerized melamine-formaldehyde resin (MFR) as the carbon sources were synthesized via the decomposition of MFR/Fe3O4/rGO nanocomposites. Fe3O4 NPs were embedded in the integrated carbon matrix composed of protective carbon layer and conductive rGO sheets offering excellent buffer effect. The NC@Fe3O4/rGO nanocomposites were tested as anode materials for lithium-ion batteries (LIBs) and displayed a large reversible specific capacity of above 900 mA h g−1 after 100 cycles at a current density of 50 mA g−1, high coulombic efficiency (~ 98%) with an initial coulombic efficiency of 86%. The high initial coulombic efficiency is critical for the practical application of the transition metal oxide–based anode materials.