Charge/discharge cycles on Pt and Pt-Ir based electrodes for the positive side of the Zinc-Cerium hybrid redox flow battery

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• 作者：Georgios Nikiforidis ; ^{gnikifor@cityu.edu.hk" class="auth_mail} ; L&eacute ; onard Berlouis ; David Hall¹ ; David Hodgson²
• 关键词：Ce3+/Ce4+ reaction ; Platinum and Iridium electrodes ; Rotating disk electrode ; Methanesulfonic acid ; Voltage efficiency ; Redox flow battery.
• 刊名：Electrochimica Acta
• 出版年：10 April, 2014
• 年：2014
• 卷：125
• 期：Complete
• 页码：176-182
• 全文大小：1834 K

文摘

In this study, the charge/discharge cycling behaviour of the Ce³⁺/Ce⁴⁺ redox couple in methanesulfonic acid medium on various Pt and Pt-Ir coated titania based substrates was investigated as a function of solution flow rate, temperature and charge/discharge current density using a rotating disk electrode. Although superior performances (in terms of the voltage efficiency, 畏_V) were obtained from the electrodes containing higher amounts of platinum, a deterioration of these electrodes with cycling was evident (after 150 cycles). At rotation rates between 600 rpm and 1200 rpm, high 畏_V (>90%) could be obtained as long as the current density j applied was below the mass transport limiting current density, j_L. For j's above this value, the oxygen evolution reaction occurred with Ce³⁺ oxidation whereas the Ce⁴⁺ reduction was accompanied by oxygen reduction, resulting in lowered 畏_V's. Better stability towards cycling and higher 畏_V's were observed at 60 掳C compared to 25 掳C, especially for the etched Pt electrodes. The optimum loading for the Pt substrates was 3 g m^鈭? while for the case of the heat treated samples 10 g m^鈭? of Pt.