Abstract
Hollow nanostructured materials are attractive in material science for both fundamental research and practical applications. In this study, anodization demonstrates its convenience and effectiveness for constructing elaborate hollow nanospheres, based on an interesting synthetic mechanism involving bubble-assisted anodic self-assembly. The thus fabricated hierarchical FeS/FeOx hollow nanospheres are directly grown on the Fe substrate, providing a novel type of binder-free anode for high-performance batteries. For instance, when applied in sodium ion batteries, the air-annealed anode delivers high capacity and stability, retaining 464.8 mA h g−1 after 100 cycles at 100 mA g−1.
A simple, scalable, and cost-effective anodization method was developed to construct hierarchical FeS/FeOx hollow nanospheres on Fe substrate. [Display omitted]
•A scalable one-step anodization method is used to obtain hollow nanospheres.•Hierarchical FeS/FeOx hollow nanospheres are directly self-grown on the substrate.•Bubble-assisted self-assembly mechanism is proposed during anodization.•Binder-free FeS/FeOx anode delivers a high performance for Na-ion storage.