Controllable synthesis of hollow MnFe2O4 by self-etching and its application in high-performance anode for lithium-ion batteries

The performance of anode materials is critical in further development of Li-ion batteries. However, the reversible capacity and cycling stability of anode materials are still far from satisfying. In this study, a new hollow MnFe2O4-carbon nanospheres (H-MnFe2O4-C) synthesized via an in-situ self-etching method was proposed. The MnFe2O4 served as the structural platform to embed the D-galactose coating layer followed by the in situ carbonization, the composite was then etched to form functional mesoporous H-MnFe2O4-C. The possible formation mechanism were discussed in detail. Based on the advantages of the hollow superstructure, close-packed configuration and uniform carbon coatings, which facilitate lithium-ion and electron transport while simultaneously alleviating the drastic volumetric change during cycling, the H-MnFe2O4-C exhibit high reversible capacity and outstanding cycling stability (with 973 mAh·g−1 after 500 cycles at the current density of 0.2 A·g−1, and 603 mAh·g−1 at a high current density of 1 A·g−1), as well as high coulombic efficiency (>98%). The findings in this study are useful for the engineering design of porous carbon-coated composite, which can be used for Li-ion batteries applications and other fields.