Carbon-Coated Magnesium Ferrite Nanofibers for Lithium-Ion Battery Anodes with Enhanced Cycling Performance

摘要

Carbon-coated magnesium ferrite (MgFe2O4@C) nanofibers were synthesized by electrospinning technology and a subsequent carbonization process using polydopamine as carbon precursor. SEM and TEM observations revealed that N-doped carbon layers with different thicknesses were coated uniformly on the surface of the MgFe2O4 nanofibers. If used as anode materials for lithium-ion batteries (LIBs), MgFe2O4@C nanofibers with a carbon thickness of 7nm exhibited an excellent cycling performance and rate capability compared with pristine MgFe2O4 and MgFe2O4@C nanofibers with carbon thicknesses of 4 and 15nm, respectively. These nanofibers delivered high initial discharge and charge capacities of 1383 and 1044mAhg(-1), respectively, with a Coulombic efficiency of 75.5. A reversible capacity of 926mAhg(-1) could be obtained after 200cycles at 0.1Ag(-1). Even at a high rate of 1Ag(-1) after 500cycles, they still maintained a stable capacity of 610mAhg(-1) with a capacity retention of 81.9. Therefore, the MgFe2O4@C nanofibers are a potential anode candidate for LIBs.