Double Confined MoO₂/Sn/NC@NC Nanotubes: Solid-Liquid Synthesis, Conformal Transformation, and Excellent Lithium-Ion...

The rational design of a hollow heterostructure promotes the development of highly durable anode materials for lithium-ion batteries. Herein, carbon-confined MoO₂/Sn/NC@NC heterostructured nanotubes evolving from MoO₃ nanorods have been successfully synthesized for the first time. In the growth of the Mo/Sn precursor, a peculiar microstructure evolution occurs from solid rods to hollow tubes through a solid-liquid reaction. The MoO₂/Sn composite is restricted within the double carbon layer after subsequent annealing and carbonization that distinctly inherits the morphology of the Mo/Sn precursor. The resulting electrode shows good capacities with hardly any attenuation (925.4 mA h g^-1 after 100 cycles at 100 mA g^-1) and excellent long cycle life (620.1 mA h g^-1 after 1000 cycles at 2 A g^-1). The MoO₂/Sn/NC@NC nanotubes contain the synergistic effect, elaborate core-shell structure, large specific surface areas, and abundant voids. These superiorities not only provide beneficial channels for the electrolyte to fully come into contact with electrode materials and more active sites for redox reactions but also effectively alleviate the volume fluctuation and sustain the electrical connectivity to retain a stable solid-electrolyte interface layer, indeed, bringing about the prominent Li-storage performance. The present study paves a feasible avenue to prepare core-shell structures with high reversible capacity and long-term cycle performance for energy storage devices.