CoFe ₂ O ₄ nanoparticles directly grown on carbon nanotube with coralline structure as anodes for lithium ion battery

In this work, tiny CoFe ₂ O ₄ nanoparticles with a diameter of several nanometers were firmly grown on carbon nanotube (CNT) through a solvothermal process followed with calcination step. The composite shows a coralline structure, where CoFe ₂ O ₄ nanoparticles are dispersed finely on the surface of CNT. The coralline CoFe ₂ O ₄ –CNT composite electrode can deliver initial discharge/charge capacities of 1183.6/876.1 mAh g ⁻¹ at 100 mA g ⁻¹ , with a Coulombic efficiency reaching up to 74.0%. The capacity drops first but ascends latter when the electrode is cycled 220 times at 200 mA g ⁻¹ , giving a value of 747.5 mAh g ⁻¹ at 220th discharge process. Besides, the composite displays a capacity of 620.8 mAh g ⁻¹ even at a high rate of 1600 mA g ⁻¹ , larger than commercialized graphite (372 mAh g ⁻¹ ). Thus, coralline CoFe ₂ O ₄ –CNT composite of remarkable electrochemical properties makes it a promising anode for lithium ion batteries.