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Composites based on carbon nanotubes and ZnO particles with needle shapes were prepared for applications in energy storage. Depending on the temperature (85 or 25 °C) at which the reaction between NaOH and ZnCl(2) was carried out, particles with two different morphologies: needle-shaped (NS) and double-pyramid-shaped (DPS), respectively, are obtained. Scanning electron microscopy, photoluminescence, UV-Vis absorption spectroscopy, x-ray diffraction and Raman light scattering studies reveal that the NS and DPS particles belong to ZnO with wurtzite (WZ) structure and ε-Zn (OH)(2) as precursors of ZnO, respectively. Using the ZnO/carbon nanotube composite as a negative electrode and an electrolytic solution containing LiPF(6), the charge-discharge characteristics of rechargeable lithium ions cells were determined. Additional information concerning the electrochemical reactions at the interface of the two electrodes was obtained by cyclic voltammetry.

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Some experimental results concerning the decay times of the luminescence emission of Pbe+ centres in KCl and NaCl crystals are reported and discussed in order to clarify the origin of the two emissions excitable in the A absorption band. The experimental features support the luminescent Pbe+ centre model implying a resonant energy transfer.Des r6sultats experimentaux concernant l'extinction des 6missions luminescentes des centres Pb2+ en cristaux de NaCl et KCl sont pr6sentks et discutes dans le but de clarifier l'origine des deux 6missions produites par irradiation dans la bande A d'absorption. Les donnks exp6rimentales sont en bien accord avec le modhle de centre luminescent impliquant un transfert r6sonan. d'6nergie.