Flexible Mn₃O₄/MXene Films with 2D–2D Architectures as Stable and Ultrafast Anodes for Li-Ion Batteries

Mn3O4 is regarded as a promising anode material for lithium-ion batteries (LIBs) based on its ultrahigh theoretical capacity (937 mAh g–1) and low cost but suffers from poor electronic conductivity and large volume variation during the lithiation/delithiation process, which result in dramatic capacity fading and inferior rate capability. Ti3C2Tx MXene, a novel two-dimensional transition metal carbide with metallic conductivity, excellent mechanical properties, and hydrophilic surface, could be an ideal candidate to improve the lithium storage performance of Mn3O4. Here, a unique flexible, 2D–2D Mn3O4/MXene film is fabricated by assembling 2D Mn3O4 with Ti3C2Tx nanosheets through a simple vacuum filtration approach. In this unique 2D–2D nanostructure, MXene nanosheets buffer the volume change of Mn3O4 during the charge/discharge process. Moreover, the introduction of MXene enables the fabricated 2D–2D nanostructure with excellent flexibility and can be directly used as an electrode for LIBs, which is beneficial for enhancing the energy density of the assembled batteries. As a result, the flexible film of Mn3O4-MXene-8-2 shows excellent lithium storage performances in terms of specific capacity (931 mAh g–1 at 0.05 A g–1), rate capability (624 mAh g–1 at 1 A g–1), and cycling stability, demonstrating its great potential for the application in LIBs.