Hybrid Tin Oxide Nanotube Arrays As Anodes for Lithium Ion Batteries

Compared to traditional anodes based on nanostructured powdered paste, directly grown, one-dimensional ordered nanostructured array offers remarkable advantages such as fast-electron transport/collection and ion diffusion, sufficient electrochemical reaction of individual nanostructures, enhanced material-electrolyte contact area and facile accommodation of the strains caused by lithium intercalation and de-intercalation. Amongst various ordered metal oxide arrays, SnO₂ has been regarded as one of the most promising candidates for alternative anode material for Li-ion batteries due to the high theoretical capacity (781 mAh/g) compared to that of graphite (372 mAh/g). Thus, making 1D oriented nanostructure array of SnO₂ on metal substrate over a large area and further applying it as anode of battery is highly desirable for the exploration of novel electrode materials. Large-scale growth of uniform SnO₂ nanotube arrays on Ti substrate, with high orientation consistency, was achieved through a low temperature hydrothermal process. Furthermore, hybrid Sn-SnO₂ nanotubes were created by reducing the as-synthesized SnO₂ nanotubes.  The performance of these arrays as anode materials in lithium-ion batteries was evaluated.