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.