Smartly Designed Hierarchical MnO2 @Fe3 O4 /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 @Fe3 O4 /CNT hybrid films, in which MnO2 nanosheets, Fe3 O4 nanoparticles and CNTs are hierarchically assembled in a unique stage of nanosheets-nanoparticles-nanotubes. The resulting MnO2 @Fe3 O4 /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.