کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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220996 | 463366 | 2007 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Chronoamperometric measurements and modeling of nucleation and growth, and moving boundary stages during electrochemical lithiation of graphite electrode Chronoamperometric measurements and modeling of nucleation and growth, and moving boundary stages during electrochemical lithiation of graphite electrode](/preview/png/220996.png)
Chronoamperometric studies of the stage 2 (LiC12) to stage 1 (LiC6) transition during electrochemical insertion of Li ions into graphite electrodes showed 5 distinct domains in their current vs. time curves. A linear increase of current at the beginning of domain II and a decrease in current with time within domain IY were identified with two-dimensional instantaneous nucleation of cylindrical grains of stage 1 into stage 2, their growth and further coalescence with the formation of the continuous moving boundary. We could calculate the following characteristic parameters: the nucleation time constant, τn = 990 s; the density of nucleation sites No = 2.5 × 108 cm−2, the velocity of the lateral growth of cylindrical nuclei, a = 3.6 × 10−8 cm s−1 and the thickness of the nucleation layer, d = 0.36 μm. After nucleation stage, the interphase propagates initially linearly with time and then proportionally to the square root of time (domain IV). At 30 °C the speed of propagation of the moving boundary between stage 1 and stage 2, dξ/dt′, is around 1.6 × 10−7 cm s−1. The activation energies of a, dξ/dt′ and D1 obtained from the related Arrhenius plots were found to be 0.13, 0.19 and 0.23 eV, respectively.
Journal: Journal of Electroanalytical Chemistry - Volume 600, Issue 1, 1 February 2007, Pages 13–22