Ionic liquid derived nitrogen-doped graphite felt electrodes for vanadium redox flow batteries
Ionic liquid derived nitrogen-doped graphite felt electrodes for vanadium redox flow batteries
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DOI：
10.1016/j.carbon.2020.05.002
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发表时间：
2020-09
期刊：
影响因子：
10.9
通讯作者：
S. Yoon;Sangwon Kim;Dong Kyu Kim;Soonyong So;Y. Hong;R. Hempelmann
中科院分区：
文献类型：
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作者：
S. Yoon;Sangwon Kim;Dong Kyu Kim;Soonyong So;Y. Hong;R. Hempelmann
提出了一种制备钒氧化还原液流电池高电催化活性掺氮石墨毡电极的简便方法。通过在石墨毡表面涂覆1-乙基-3-甲基咪唑二氰胺（EMIM dca），然后在N2气氛下进行热处理，制备了掺氮石墨毡。EMIM dca是一种含氮量较高的离子液体，可作为石墨毡表面氮掺杂的有效前驱体。采用扫描电子显微镜（SEM）、X射线光电子能谱（XPS）和循环伏安法（CV）对掺氮石墨毡的物理性能和电化学性能进行了表征。在充放电测试中，掺氮石墨毡单电池表现出优异的性能。与通过常规热处理方法制备的具有氧官能团的石墨毡（GF-Ref）相比，涂覆有20重量% EMM dca溶液的石墨毡（GF-Ed 20）在150 mA cm-2的电流密度下表现出三倍增加的放电容量和10%高的能量效率。性能的改善归因于石墨毡上的高氮含量，这增加了钒氧化还原反应的电催化活性。
A facile method for preparing nitrogen-doped graphite felt electrodes with high electrocatalytic activity for vanadium redox flow batteries (VRFBs) is developed. These nitrogen-doped graphite felts are fabricated by coating 1-ethyl-3-methylimidazolium dicyanamide (EMIM dca) on the surface of graphite felts followed by thermal treatment under a N2atmosphere. EMIM dca, an ionic liquid containing a high content of nitrogen, is used as an effective precursor for nitrogen doping on graphite felt surfaces. The physical and electrochemical properties of the nitrogen doped graphite felts are characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). When employed in charge-discharge tests, the single cells with the nitrogen doped graphite felts show outstanding performance. The graphite felt coated with 20 wt% EMM dca solution (GF-Ed20) exhibits three times increased discharge capacity and 10% higher energy efficiency at a current density of 150 mA cm−2compared to the graphite felt with the oxygen functional groups (GF-Ref) prepared by the conventional heat treatment method. The improved performance is attributed to the high nitrogen content on the graphite felt, which increases the electrocatalytic activity of vanadium redox reactions.