Constructing bimetallic oxides with yolk structure enables high efficient anode for lithium ion batteries

Developing anode materials with high specific capacity, excellent rate performance and cycling performance is of great significance. Herein, transition metal oxides (TMOs) have been aroused much interest owing to their low cost, large theoretical capacity and chemical stability. In this work, the bimetallic oxides CoFe 2 O 4 /C composite is synthesized by solvothermal and subsequent annealing process. When used as the anode for lithium ion batteries , the CoFe 2 O 4 /C microspheres exhibit a reversible specific capacity of 1270 mAh g −1 at 100 mA g −1 after 100 cycles and about 500 mAh g −1 at a high current density of 1.0 A g −1 after 1000 cycles. These satisfactory electrochemical properties are mainly attributed to the unique yolk structure, the synergistic effect of two metal ions , carbon coating and small nanoparticles of CoFe 2 O 4 /C. This work provides an effective synthesis method for mixed TMOs with high-performance lithium storage for LIB applications.