کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
184152 459570 2015 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nanoporous hard carbon anodes for improved electrochemical performance in sodium ion batteries
ترجمه فارسی عنوان
آنوداهای کربن نانو پودر برای بهبود عملکرد الکتروشیمیایی در باتری های یون سدیم
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی


• Nanoporous hard carbon was synthesized via a thermal decomposition of bicarbonates.
• Particle size and pore structure were sensitive to the amount of bicarbonates.
• Hard carbon with optimal porosity showed 1.4-fold increase in Na+-storage capability.
• The rate performance was also superior when compared with unmodified hard carbon.
• Enhancement in kinetics resulted from both decrease in RCT and increase in DNa.

The porosity and morphology of sucrose-based hard carbon (SHC) was regulated by varying the amount of bicarbonate salts added during a simple two-stage sintering process. During the first–stage thermal treatment of sugar at 200 °C, CO2 liberated from bicarbonate contributed to the pulverization of particles and to the formation of submicron-sized pores. Na2CO3 entrapped in a precursor matrix also released CO2 during the second–stage sintering at 850 °C, producing nanometric pores (ca. 10 nm in diameter). The excessively high content of bicarbonates, however, resulted in paper-thin graphitic layers with no submicron-sized pores. These dual roles of bicarbonates produced nanoporous SHC (NSHC) with the submicron-to-nano-sized pores and the largest surface area that was possible for a specific bicarbonate concentration. The optimal nanoporosity of NSHC lent itself to a sharp increase in reversible capacity. Reversible capacity of 324 and 289 mA h g−1 were obtained for the first and 100th cycles at 20 mA g−1, in contrast to 251 and 213 mA h g−1, respectively, for SHC. The rate capability of NSHC also was enhanced due to a substantial decrease in the charge transfer resistance and a 5-fold increase in the Na+ diffusion coefficient.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 161, 10 April 2015, Pages 23–31
نویسندگان
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