3D porous structure Fe3O4@SnO2/MXene composites with enhanced electrochemical performance for lithium ion battery anode

The low theoretical capacity of the commercial graphite electrodes used in lithium-ion batteries (LIBs) necessitates the development of novel anode materials with higher rate performance, reversible specific capacities, long cycle lives, and low costs. In this work, three-dimensional porous structure Fe3O4 nanosphere with extremely thin SnO2 coatings are prepared by a method of getting twice the result with half the effort. And it was uniformly dispersed in an MXene flexible conductive matrix to fabricate a 3D porous heterogeneous Fe3O4@SnO2/MXene composite to act as an anode material for LIBs. The 3D porous heterojunction structure integrates the advantages of Fe3O4@SnO2 and MXene, achieving rapid electron and ion transport at the interface and the effective release of structural stress. The introduction of MXene markedly enhances the conductibility of the materials, limits the expansion of Fe3O4 during the Li+ insertion/removal process, and inhibits its aggregation. The Fe3O4@SnO2/MXene anode exhibits excellent electrochemical performance (1609 mAh g−1 over 200 cycles at 100 mA g−1 and 626.1 mAh g−1 over 900 cycles at 1000 mA g−1). These findings demonstrate that the Fe3O4@SnO2/MXene composite is a promising anode material for LIBs.