Further surface modification by carbon coating for in-situ growth of Fe₃O₄ nanoparticles on MXene Ti₃C₂ multilayers for advanced Li-ion storage

Herein, a new nanocomposite was synthesized via in-situ growth of Fe₃O₄ nanoparticles on MXene Ti₃C₂ multilayer to improve the electrochemical performance of anodes by integrating the merits of transition metal oxide and Ti₃C₂, where further surface modification of Fe₃O₄@Ti₃C₂ nanocomposites by carbon coating was introduced here. The nanocomposites exhibited excellent electrochemical performance in Li-ion storage when used as the anode materials, which benefited from the combination of the high capacity of magnetite and favorable electrical conductivity of Ti₃C₂. The optimized Fe₃O₄@Ti₃C₂-2.5 (a mass ratio of 1.1) showed a high reversible capacity of 342.9 mAh·g⁻¹ at 1C, which exceeded the theoretical capacity of bare Ti₃C₂ monolayer (320 mAh·g⁻¹), and an impressive rate reversibility. TEM presented that the carbon layers were homogeneously coated on the surface of nanocomposites with a thickness of approximately 1 nm. The electrochemical measurement showed that C-coated Fe₃O₄@Ti₃C₂-2.5 presented enhanced cycling performance (382.9 mAh·g⁻¹ at 1C and 236.7 mAh·g⁻¹ at 5C) and cycling stability. This work presents a promising route for preparation of transition metal oxides@MXene nanocomposites as well as further surface modification for advanced Li-ion storage.