Zn–Fe–ZIF-derived porous ZnFe2O4/C@NCNT nanocomposites as anodes for lithium-ion batteries

Abstract

A novel hybrid of porous ZnFe₂O₄/carbon (C)@nitrogen-doped carbon nanotube (NCNT) nanocomposites with a high surface area of 256 m² g⁻¹ is synthesized by a one-step pyrolysis of Zn–Fe–ZIF as a precursor and sacrificial template. The porous ZnFe₂O₄/C@NCNT nanocomposites, possessing a large carbon content of about 50 wt%, deliver an initial discharge of 2192 mA h g⁻¹ and still reach a high reversible capacity of 844 mA h g⁻¹ after 100 cycles at a current density of 100 mA g⁻¹. The sample also exhibits an exceptional rate capability of 747 mA h g⁻¹ at a large current density of 1 A g⁻¹. The unusual construction in which ZnFe₂O₄ nanoparticles are homogeneously distributed in the entire carbon framework coated by NCNTs may mainly contribute to the good electrochemical performance. Therefore, the resulting porous ZnFe₂O₄/C@NCNT nanocomposites are potentially useful for rechargeable LIBs.