Ultrafast pyro-synthesis of NiFe2O4 nanoparticles within a full carbon network as a high-rate and cycle-stable anode material for lithium ion batteries

Abstract

NiFe₂O₄ nanoparticles fully anchored within a carbon network were prepared via a facile pyro-synthesis method without using any conventional carbon sources. The surface morphology was investigated using field-emission scanning electron microscopy, which confirmed the full anchoring of NiFe₂O₄ nanoparticles within a carbon network. The primary particle size of NiFe₂O₄ is in the range of 50–100 nm. The influence of the carbon network on the electrochemical performance of the NiFe₂O₄/C nanocomposite was investigated. The electrochemical results showed that the NiFe₂O₄/C anode delivered a reversible capacity of 381.8 mA h g⁻¹ after 100 cycles at a constant current rate of 1.0C, and when the current rate is increased to a high current rate of 5.0C, a reversible capacity of 263.7 mA h g⁻¹ is retained. The obtained charge capacity at high current rates is better than the reported values for NiFe₂O₄ nanoparticles. The enhanced electrochemical performance can be mainly ascribed to the high electrical conductivity of the electrode, the short diffusion path for Li⁺ ion transportation in the active material and synergistic effects between the NiFe₂O₄ nanoparticles and carbon network, which buffers the volume changes and prevents aggregation of NiFe₂O₄ nanoparticles during cycling.