Exploring Carbonyl Chemistry in Non‐aqueous Mg Flow Batteries
Exploring Carbonyl Chemistry in Non‐aqueous Mg Flow Batteries
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探索非水镁液流电池中的羰基化学
DOI：
10.1002/asia.202200587
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Gao, Tao
中科院分区：
文献类型：
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作者：
Qin, Yunan;Holguin, Kathryn;Fehlau, Dillon;Luo, Chao;Gao, Tao
非水氧化还原液流电池（RFB）是用于电网储能的新兴电化学技术。使用Mg金属作为阳极的非水Mg RFB由于Mg金属阳极的各种益处（包括其低电势、高体积容量、无SEI、高度可逆操作和低成本）而特别有前景。尽管有潜力，但很少有关于开发非水Mg RFB的任何研究。在本文中，报道了使用聚合物阴极电解液的非水性Mg氧化还原液流电池。通过合理的分子工程，羰基基部分与聚乙二醇部分结合，以获得在醚基电解质中具有高电压和高溶解度的聚合物。合成了一系列具有不同聚乙二醇链长的聚合物，并首先在分子水平上测量它们的性能，然后在使用镁箔作为阳极、聚合物溶液作为阴极电解液和多孔膜作为隔膜的镁氧化还原液流电池中在器件水平上测量它们的性能。该液流电池输出电压为1.8V，最大容量为475 mAh/L，平均库仑效率为90.5%，平均电压效率为67.4%，能量效率为61.0%，能量密度为0.855Wh/L。 系统的机制进行研究，以了解性能衰减机制和未来的改进可能的策略进行了讨论。这项工作为电网电力存储的储能技术的发展开辟了新的途径。
Non‐aqueous redox flow batteries (RFBs) are emerging electrochemical technologies for grid energy storage. Non‐aqueous Mg RFBs that use Mg metal as the anode are especially promising due to various benefits of the Mg metal anode, including its low potential, high volumetric capacity, SEI‐free, highly reversible operation and low cost. Despite the potential, there are rarely any studies on developing non‐aqueous Mg RFBs. Herein, a non‐aqueous Mg redox flow battery using a polymer catholyte is reported. Through rational molecular engineering, a carbonyl‐based moiety is combined with a polyethylene glycol moiety to achieve a polymer with high voltage and high solubility in the ether‐based electrolyte. A series of polymers with different polyethylene glycol chain lengths are synthesized and their performances are measured first at the molecular level, and then at the device level in a Mg redox flow battery using a Mg foil as the anode, the polymer solution as the catholyte and a porous membrane as the separator. The flow battery delivers a voltage of 1.8 V, a maximum capacity of 475 mAh/L, an average Coulombic efficiency of 90.5%, an average voltage efficiency of 67.4%, an energy efficiency of 61.0%, and an energy density of 0.855 Wh/L. Systematic mechanistic studies are performed to understand the performance decay mechanism and possible strategies for future improvement are discussed. This work opens a new avenue for the development of energy storage technologies for grid electricity storage.