Coaxial structure of NiFe2O4/CNTs composites as anodes for enhanced lithium ion batteries

Abstract

Coaxial-structure NiFe2O4/CNTs composites are fabricated via self-assembly technique and a subsequent pyrolysis process. Porous structure and NiFe2O4 nanoparticles are created by using metal-organic framework as sacrificial templates, and NiFe2O4 with the particles size of 5 nm are uniformly distributed along the inside wall of CNTs to form coaxial structure. As an anode material for lithium ion batteries (LIBs), the porous NiFe2O4/CNTs electrode demonstrates a high reversible capacity of 624.6 mAh g−1 after 100 cycles at the current density of 100 mA g−1. Even increased to 2000 mA g−1, it still remains the capacity of 250 mAh g−1 after 100 cycles. This attractive electrochemical performance may be attributed to its robust coaxial structure, well-marked porosity and unhindered Li-ion transportation, rendering it a potential anode material for LIBs.