کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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186091 | 459607 | 2014 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Studies on the lithium ion diffusion coefficients of electrospun Nb2O5 nanostructures using galvanostatic intermittent titration and electrochemical impedance spectroscopy Studies on the lithium ion diffusion coefficients of electrospun Nb2O5 nanostructures using galvanostatic intermittent titration and electrochemical impedance spectroscopy](/preview/png/186091.png)
• Pseudo-hexagonal (H), orthorhombic (O), and monoclinic (M) Nb2O5 phases were prepared by electrospunning.
• They were characterized by SEM, Galvanostatic and Impedance techniques.
• DLi values by GITT for H-, O-, and M-Nb2O5 are in the range, 10−17–10−16, 10−15–10−14, and 10−13–10−12 cm2 s−1, respectively.
We have studied the Li-diffusion coefficient values of electrospun Nb2O5 nanofibers and nanonuggets for lithium batteries. In brief, Nb2O5 nanofibers were prepared by electrospinning followed by sintering at temperatures range 500–1100 °C for 1 h in air to obtain pseudo-hexagonal, orthorhombic (O), and monoclinic (M) Nb2O5 phases. Electrochemical properties were evaluated by galvanostatic technique at room temperature. The H-, O- and M-Nb2O5 polymorphs delivered discharge capacities (at second cycle) of 152, 189 and 242 (±5) mA h g−1, respectively. The lithium diffusion coefficients (DLi) are calculated using galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) techniques carried at room temperature. The evaluated DLi values by GITT for H-, O-, and M-Nb2O5 phases are in the range 10−17–10−16, 10−15–10−14, and 10−13–10−12 cm2 s−1, respectively, in the voltage range 1.0–2.6 V vs. Li. DLi evaluated by EIS gave similar trend in the values but with a difference of one order higher magnitude.
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Journal: Electrochimica Acta - Volume 128, 10 May 2014, Pages 198–202