کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1284062 1497967 2014 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modified carbon-free silver electrodes for the use as cathodes in lithium–air batteries with an aqueous alkaline electrolyte
ترجمه فارسی عنوان
الکترود نقره ای بدون کربن اصلاح شده برای استفاده به عنوان کاتد در باتری های لیتیوم با یک الکترولیت قلیایی آب
کلمات کلیدی
باتری باتری لیتیوم، کاهش اکسیژن، تکامل اکسیژن، الکترود نقره ای، الکترود اکسید کبالت، الکترولیت قلیایی
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
چکیده انگلیسی


• High activity bi-functional catalyst combination for ORR and OER.
• An optimum ratio of high active bi-functional catalysts was found.
• Novel electrodes without carbon to avoid carbon corrosion during OER mode.
• EIS models for ORR and OER describe influence of a growing oxide layers.
• Long-term test exhibited an excellent long-term stability over 200 cycles.

Gas diffusion electrodes with silver catalysts show a high activity towards oxygen reduction reaction in alkaline media but a rather poor activity towards oxygen evolution reaction. For the use in future lithium–air batteries with an aqueous alkaline electrolyte the activity of such electrodes must be improved significantly. As Co3O4 is a promising metal oxide catalyst for oxygen evolution in alkaline media, silver electrodes were modified with Co3O4. For comparison silver electrodes were also modified with IrO2. Due to the poor stability of carbon materials at high anodic potentials these gas diffusion electrodes were prepared without carbon support to improve especially the long-term stability. Gas diffusion electrodes were electrochemically investigated in an electrochemical half-cell arrangement. In addition to cyclic voltammograms electrochemical impedance spectroscopy (EIS) was carried out. SEM and XRD were used for the physical and morphological investigations. Investigations showed that silver electrodes containing 20 wt.% Co3O4 exhibited the highest performance and highest long-term stability. For comparison, rotating – ring – disc – electrode experiments have been performed using model electrodes with thin catalyst layers, showing that the amount of hydrogen peroxide evolved is negligible.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Power Sources - Volume 265, 1 November 2014, Pages 299–308
نویسندگان
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