Smartly Designed Hierarchical MnO₂@Fe₃O₄/CNT Hybrid Films as Binder-free Anodes for Superior Lithium Storage

Nowadays, the development of advanced anode materials is highly desirable for the increasing demand for high-performance lithium-ion batteries (LIBs). Nanostructured MnO₂ has received utmost attention due to high theoretical capacity (1230 mA h g⁻¹), abundant resources, environmental benignity, and shortened electron and ion diffusion paths. Unfortunately, poor electronic conductivity and strong aggregation inclination of MnO₂ nanostructures result in disappointing electrochemical performances, which restrict their practical application as sole institute. Here, we propose smartly designed MnO₂@Fe₃O₄/CNT hybrid films, in which MnO₂ nanosheets, Fe₃O₄ nanoparticles and CNTs are hierarchically assembled in a unique stage of nanosheets–nanoparticles–nanotubes. The resulting MnO₂@Fe₃O₄/CNT hybrid films can be directly used as anodes without any polymer binders, and exhibit significant synergistic interactions among three components, achieving excellent reversible capacity and rate performance.