A New Hierarchical alpha-MnO2-Nanotube@SnO2 Heterostructure as an Advanced Anode for High-Performance Lithium-Ion Batteries

A new hierarchical alpha-MnO2-nanotube@SnO2 heterostructure composing of alpha-MnO2 nanotube stem and SnO2 nanorod branches is synthesized by a facile two-step hydrothermal growth method. As an advanced anode for lithium ion batteries, the alpha-MnO2-nanotube@SnO2 heterostructures show an obvious improvement electrochemical property in terms of initial discharge capacity (1548 mAh g-1 at 100 mA g(-1) rate), and capacity retention (437 mAh g(-1) at 50th cycle at 100 mA g(-1) rate) compared to both single components. The enhanced electrochemical performance towards lithium storage may be ascribed to the hierarchical heterostructures, which can not only remain free space between neighboring hybrid nanostructures serving as structure stabilizers and provide more reaction sites, but also maintain efficient electrolyte penetration and facilitate the rapid diffusion path length for fast lithium ion transport into the electrode, and the synergistic effect between different components and the hierarchical structure, thus leading to substantially improved cycling performances.