کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
190569 | 459701 | 2010 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Investigation of lithium diffusion in nano-sized rutile TiO2 by impedance spectroscopy Investigation of lithium diffusion in nano-sized rutile TiO2 by impedance spectroscopy](/preview/png/190569.png)
The kinetics of the electrochemical lithium insertion reaction in nano-sized rutile TiO2 has been investigated using ac impedance spectroscopy. The experimental data are obtained for a rutile compound synthesized via a solution technique and characterized by a morphology corresponding to spherical particles made of a large number of very thin nanorods 20 nm thick. The results are discussed as a function of the Li content x for 0 < x ≤ 0.8 in LixTiO2, the temperature over the range 10–50 °C and the number of discharge–charge cycles. The significant linear decrease of the chemical diffusion coefficient DLivs. the lithium content and the high values of DLi found in the composition range 0 < x ≤ 0.5 are discussed and related with the electrochemical behaviour of the nano-sized material. From comparison with the bulk material, a promoting effect of the morphology on the kinetic characteristics is evidenced. For the first time an experimental evaluation of the activation energy for Li diffusion in nano-sized rutile TiO2 is obtained; the value of 0.35 eV being much lower than that reported from computational experiments for the micro-sized oxide. This work also demonstrates a new system takes place from the second cycle, characterized by a significant improvement of Li diffusion by a factor five and allowing high rates to be used.
Journal: Electrochimica Acta - Volume 55, Issue 17, 1 July 2010, Pages 4952–4959