NiFe₂O₄ porous nanorods/graphene composites as high-performance anode materials for lithium-ion batteries

NiFe₂O₄ porous nanorods/graphene composites are synthesized by a solvothermal method in combination with calcination at 400 °C. Uniform NiFe₂O₄ porous nanorods with a diameter of about 300 nm and a length of several micrometers are homogeneously anchored on graphene sheets. The close and firm contact between the two components assures the sound electrochemical properties. The lithium-ion battery performance of the composites anode is evaluated by galvanostatic and rate performance. NiFe₂O₄ porous nanorods/graphene composites electrode exhibit a superior lithium storage capability. The first discharge capacity of the composites electrode is 1115 mA h g⁻¹ at a current density of 1 A g⁻¹, and still maintains at 655 mA h g⁻¹ even after 600 cycles. Even at a high current density of 5 A g⁻¹, a high reversible specific capacity of 509 mA h g⁻¹ can be achieved. The synergistic effect between graphene with excellent electrical conductivity and NiFe₂O₄ nanorods with porous structure makes a substantial contribution to the outstanding electrochemical performance.