Preparation Of Fe ₃ 4 / C Composites And Its Performance As Anode Materials For Lithium Ion Batteries

Ferrous ferric oxide(Fe3O4) anode material attracted more and more attention because of its high theoretical specific capacity, abundant resources, cheap and environmentally friendly. However, the volume effect and poor conductivity restricts seriously its application and further development as anode electrode materials. This dissertation investigated a series of Fe3O4/C composite material with excellent electrochemical performance obtained through the method of RAPET and solvent thermal process. The main contents go as follows:1)Ferrocene and tetrahydrofuran have been used as precursors for the synthesis of Fe3O4/C composite material with the method of PAPET. The influence of ratio between the two reagents of ferrocene and tetrahydrofuran on the properties of products has been explored. The results show that the Fe3O4/C material possess excellent electrochemical performance when the iron source quantity is 0.4 g and the volume of tetrahydrofuran is 2ml, which still can maintain a reversible specific capacity of 538 m Ah/g after 50 cycles.2) Fe3O4/graphene composite materials gave been prepared by a high-temperature one-step solvothermal method. A preferred solvothermal temperature of 280 ℃ has been deduced based on a series of control experiments. The Fe3O4/graphene composite derived at 280℃exhibits a high reversible capacity of 907 m Ah/g at 0.1C even after 65 cycles, showing outstanding cycle stability. It also exhibited a high ratecapability of 410 m Ah/g at 2C.3) Fe3O4 materials with different morphologies have been synthesized through the hightemperature solvothermal process. The influences of different reaction time and reaction temperature on material properties were investigated. The results indicate that the fibrous Fe3O4 which were prepared at 350℃ for 12 h own high performance electrochemical properties. The capacity of the material still remains at 791 m Ah/g after 50 cycles at a current density of 100 m A/g.