SnO₂ nanotube arrays embedded in a carbon layer for high-performance lithium-ion battery applications

A facile strategy for preparing one-dimensional (1D) SnO₂ nanotube arrays embedded in a carbon layer (C-SnO₂ NTs) has been developed via a sol-gel method using polycarbonate (PC) as a template. The introduction of a carbon layer (carbonized from a PC membrane) at the top of SnO₂ nanotube arrays results in the SnO₂ nanotubes standing on the current collector and preserving their 1D structure without aggregation between each other, which enables their direct application to the anode of lithium-ion batteries. The binder- and carbon-free C-SnO₂ NTs as a self-supporting anode exhibits a stable and high reversible capacity of 500 mA h g^-1 at 0.1 A g^-1 after 40 cycles. The improved Li ion storage and stable capability are attributed to the 1D hollow structure, alleviating the large volume changes of SnO₂ and enhancing electron and Li ion diffusion transport in the nanotubes.