One-Step Fabrication of Fe-Si-O/Carbon Nanotube Composite Anode Material with Excellent High-Rate Long-Term Cycling Stability

Abstract The composite of Fe 2 SiO 4 with carbon nanotubes, Fe 3 O 4 and Fe 3 C are fabricated by a simple one-step reaction between ferrocene and tetraethyl orthosilicate. The composite utilized as anode material for Li-ion storage exhibits ever-increasing capacities when cycled at a current density of 100 mA g −1 , and after 280 cycles, a stable capacity of 588 mAh g −1 is achieved. When cycled at 200, 400, 800 and 1600 mA g −1 , the reversible capacities are 364, 323, 281, 235, and 186 mAh g −1 , respectively. Even cycled at 500 mA g −1 , a reversible capacity of 350 mAh g −1 is retained after 600 cycles. The excellent performance is much superior to that of the carbon-coated Fe 3 O 4 prepared under the similar conditions. The outstanding performance associates significantly with the electronic conductivity of in-situ formed carbon nanotubes with uniform dispersion and Fe 3 C coated on the Fe 2 SiO 4 nanoparticles, as well as the formation of lithium silicates to act as solid electrolyte for enhancing the ionic conductivity.