A Systematic Electrochemical Investigation of a Dimethylamine Cosolvent-Assisted Nonaqueous Zinc(II) Bis(trifluoromethylsulfonyl)imide Electrolyte
A Systematic Electrochemical Investigation of a Dimethylamine Cosolvent-Assisted Nonaqueous Zinc(II) Bis(trifluoromethylsulfonyl)imide Electrolyte
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DOI：
10.1149/1945-7111/abe9cb
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发表时间：
2021-03
影响因子：
3.9
通讯作者：
G. Asselin;O. Paden;W. Qiu;Zicheng Yang;Niya Sa
中科院分区：
文献类型：
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作者：
G. Asselin;O. Paden;W. Qiu;Zicheng Yang;Niya Sa
多价电解质的开发是推进多价储能技术的重要组成部分。本文研究了一种新的、简单的非水锌电解液，并引入仲胺作为助溶剂。在THF中加入二甲胺（DMA）作为助溶剂，促进了锌（II）双（三氟甲烷磺酰基）imde （Zn (TFSI) 2）的增溶，得到了具有高库仑效率的可逆锌电镀的均匀电解质。系统地研究了制备的电解液的电化学性能以及助溶剂和盐浓度的影响。研究发现，增加助溶剂DMA在THF中对Zn (TFSI) 2电解质的比例，可以使动力学更容易，离子溶解效果更好，离子迁移率更高，电导率和镀/剥离电流密度显著增加。在THF溶剂混合物中增加2.0 M DMA中的Zn (TFSI) 2盐浓度，不仅可以提高电流密度和电导率，还可以通过再解离机制提高摩尔电导率。本研究的发现对于从简单有效的电解质设计策略进一步理解和表征多价电解质具有重要意义。
The development of the multivalent electrolytes is a critical component to advance polyvalent energy storage technology. In this work, a new and simple nonaqueous zinc electrolyte is developed and investigated where a secondary amine is introduced as a cosolvent. The addition of dimethylamine (DMA) as a cosolvent in THF facilitates the solubilization of Zinc (II) bis (trifluoromethanesulfonyl) imde (Zn (TFSI) 2) and results in a homogeneous electrolyte with reversible plating of zinc achieved at high coulombic efficiencies. The electrochemical properties of the developed electrolyte and the effects of the cosolvent and salt concentrations are systematically investigated. It was found that increasing the ratio of the cosolvent DMA in THF for a Zn (TFSI) 2 electrolyte leads to more facile kinetics, better ion solubilization, and higher ion mobility evidenced by up a significant increase in conductivity as well as the plating/stripping current densities. Increased Zn (TFSI) 2 salt concentration in a 2.0 M DMA in THF solvent mixture not only leads to a higher current density and conductivity, but also a higher molar conductivity due to a redissociation mechanism. The findings in this study are relevant and important to further understand and characterize multivalent electrolytes from a simple and effective electrolyte design strategy.