Lithiation-delithiation cycles of individual aluminum nanowires (NWs) with naturally oxidized Al(2)O(3) surface layers (thickness 4-5 nm) were conducted in situ in a transmission electron microscope. Surprisingly, the lithiation was always initiated from the surface Al(2)O(3) layer, forming a stable Li-Al-O glass tube with a thickness of about 6-10 nm wrapping around the NW core. After lithiation of the surface Al(2)O(3) layer, lithiation of the inner Al core took place, which converted the single crystal Al to a polycrystalline LiAl alloy, with a volume expansion of about 100%. The Li-Al-O glass tube survived the 100% volume expansion, by enlarging through elastic and plastic deformation, acting as a solid electrolyte with exceptional mechanical robustness and ion conduction. Voids were formed in the Al NWs during the initial delithiation step and grew continuously with each subsequent delithiation, leading to pulverization of the Al NWs to isolated nanoparticles confined inside the Li-Al-O tube. There was a corresponding loss of capacity with each delithiation step when arrays of NWs were galvonostatically cycled. The results provide important insight into the degradation mechanism of lithium-alloy electrodes and into recent reports about the performance improvement of lithium ion batteries by atomic layer deposition of Al(2)O(3) onto the active materials or electrodes.

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This paper reports a study on template-growth and electrochemical properties of single-crystal vanadium pentoxide (V 2 O 5 ) nanorod arrays from VOSO 4 aqueous solution using electrochemical deposition. Uniformly sized vanadium oxide nanorods with a length of about 10 µm with diameters ranging from 100 to 200 nm were grown over a large area with near unidirectional alignment. These nanorods have single-crystalline structure with a growth direction of [010]. Electrochemical property analysis indicates that nanorod array electrodes have significantly higher current density and energy storage density than sol-gel-derived V 2 O 5 films.

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Nanorods of lead zirconate titanate (PZT)—a ferro‐ and piezoelectric material—up to 10 μm in length and 70 to 150 nm in diameter are produced by sol‐gel electrophoresis of PZT in a track‐etched polycarbonate membrane, which is used as a template. The Figure gives a close‐up view of a PZT film with nanowires attached, as obtained after pyrolytic removal of the organic template.