کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5149667 | 1497890 | 2017 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Electrochemical modification of a pyrolytic graphite sheet for improved negative electrode performance in the vanadium redox flow battery
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
الکتروشیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The vanadium redox flow battery is a promising technology for buffering renewable energies. It is recognized that negative electrode is the limitation in this device where there are problems of slow heterogeneous electron transfer (HET) of V3+/2+ and parasitic H2 evolution. Any methods aimed at addressing one of these barriers must assess the effects on the other. We examine electrochemical enhancement of a common commercially available material. Treatment of Panasonic pyrolytic graphite sheets is through oxidation at 2.1 V vs. Ag/AgCl for 1 min in 1 M H2SO4. This increases the standard HET rate for V3+/2+ from 3.2 Ã 10â7 to 1 Ã 10â3 cm/s, one of the highest in literature and shifts voltammetric reductive peak potential from â1.0 V to â0.65 V in 50 mM V3+ in 1 M H2SO4. Infrared analysis of the surfaces indicates formation of COH, CO, and CO functionalities. These groups catalyze HET with V3+/2+ as hypothesized by Skyllas-Kasacos. Also of significance is that electrode modification decreases the fraction of the current directed towards H2 evolution. This proportion decreases by two orders of a magnitude from 12% to 0.1% as measured at the respective voltammetric peak potentials of â1.0 V (pristine) and â0.65 V (modified).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Power Sources - Volume 342, 28 February 2017, Pages 31-37
Journal: Journal of Power Sources - Volume 342, 28 February 2017, Pages 31-37
نویسندگان
Humayun Kabir, Isaiah O. Gyan, I. Francis Cheng,