Ordered arrays of parallel, cylindrical silicon nanotubes are obtained by aluminothermic reduction of SiO2 nanotubes generated by atomic layer deposition (ALD) on nanoporous aluminum oxide templates. The reduction to amorphous Si (a-Si) is characterized by a combination of X-ray diffraction (XRD), solid-state cross-polarization magic-angle spinning nuclear magnetic resonance (29Si CP-MAS NMR), ultraviolet-visible spectroscopy, attenuated total reflectance infrared spectroscopy (ATR-IR), and X-ray photoelectron spectroscopy (XPS). These a-Si nanotube arrays are electrochemically active in a lithium-ion battery environment when prepared on Cu current collectors without any additives. The absence of the traditional additive carbon black, which is an electrochemically inert conductor, increases the proportion of capacity associated with faradaic reactions (Li incorporation) with respect to the capacitive component. Electrochemical impedance spectroscopy (EIS) and charge-discharge tests demonstrate that the nanotube morphology yields an improved tolerance to fast cycling.
Предметные области Scopus
- Химическая технология (все)