Evaluation of a Non-Aqueous Vanadium Redox Flow Battery Using a Deep Eutectic Solvent and Graphene-Modified Carbon Electrodes via Electrophoretic Deposition
Evaluation of a Non-Aqueous Vanadium Redox Flow Battery Using a Deep Eutectic Solvent and Graphene-Modified Carbon Electrodes via Electrophoretic Deposition
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DOI：
10.3390/batteries6030038
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发表时间：
2020-09-01
期刊：
影响因子：
4
通讯作者：
Brandon, Nigel
中科院分区：
文献类型：
--
作者：
Chakrabarti, Barun;Rubio-Garcia, Javier;Brandon, Nigel
水基钒氧化还原液流电池（VRFB）面临的常见问题包括由于水电解副反应和高度腐蚀性和环境不友好的电解质（3至5 M硫酸）导致的电池电压低。因此，本研究着眼于高导电性离子液体与作为非水VRFBs电解质的研究充分的深共熔溶剂（DES）的比较。后一种溶剂的效率和容量利用率比前者高50%。当通过一步无粘合剂电泳沉积工艺将氮掺杂石墨烯（N-G）改性碳纸用作电极时，这些品质因数增加了10%。X射线计算机断层扫描证实了由于N-G的碳电极的电化学表面积的增加，而电化学阻抗谱显示其更高的导电性对改善RFB性能的影响。最后，潜在的战略规模的DES为基础的VRFBs使用一个简单的经济模型也简要讨论。从这项研究中，可以推断，更多的研究应用DES作为非水电解质，以取代常用的乙腈可能是一个积极的一步，因为DES不仅更便宜，而且更安全的处理，毒性小得多，不易燃，比乙腈挥发性低。
Common issues aqueous-based vanadium redox flow batteries (VRFBs) face include low cell voltage due to water electrolysis side reactions and highly corrosive and environmentally unfriendly electrolytes (3 to 5 M sulfuric acid). Therefore, this investigation looks into the comparison of a highly conductive ionic liquid with a well-studied deep eutectic solvent (DES) as electrolytes for non-aqueous VRFBs. The latter solvent gives 50% higher efficiency and capacity utilization than the former. These figures of merit increase by 10% when nitrogen-doped graphene (N-G)-modified carbon papers, via a one-step binder-free electrophoretic deposition process, are used as electrodes. X-ray computed tomography confirms the enhancement of electrochemical surface area of the carbon electrodes due to N-G while electrochemical impedance spectra show the effect of its higher conductivity on improving RFB performance. Finally, potential strategies for the scaling-up of DES-based VRFBs using a simple economical model are also briefly discussed. From this study, it is deduced that more investigations on applying DESs as non-aqueous electrolytes to replace the commonly used acetonitrile may be a positive step forward because DESs are not only cheaper but also safer to handle, far less toxic, non-flammable, and less volatile than acetonitrile.