A Stable, Low Permeable TEMPO Catholyte for Aqueous Total Organic Redox Flow Batteries
A Stable, Low Permeable TEMPO Catholyte for Aqueous Total Organic Redox Flow Batteries
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DOI：
10.1002/aenm.202102577
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发表时间：
2021-12-18
影响因子：
27.8
通讯作者：
Liu, T. Leo
中科院分区：
文献类型：
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作者：
Hu, Bo;Hu, Maowei;Liu, T. Leo
水溶性有机氧化还原液流电池（AORFBs）由于其不燃性、低成本和可持续性而对于大规模能量存储具有高度吸引力。（2，2，6，6-四甲基哌啶-1-基）氧基（克里思）衍生物是一类氧化还原活性分子，具有空气稳定的硝酰基自由基和高氧化还原电位（> 0.8Vvs NHE），被认为是AORFBs的理想阴极电解质。然而，所报道的基于克里思的分子或者可透过离子交换膜，或者对于长期能量储存而言化学稳定性不够。本文报道了一种新的双铵二阳离子基团官能化的克里思衍生物，N-1，N-1，N-1，N-3，N-3，2，2，6，6-九甲基-N-3-（哌啶氧基）丙烷-1，3-双（铵）二氯化物（N-2-克里思）作为AORFB的稳定的低渗透阴极电解液。紫外-可见（UV-vis）和质子核磁共振（H-1-NMR）光谱研究表明其具有优异的稳定性和超低渗透性（1.49 x 10（-12）cm（2）s（-1））。与作为阳极电解液的1，1 '-双[3-（三甲基铵基）丙基]-4，4'-联吡啶鎓四氯化物（（NPr）（2）V）偶联，具有0.5m电解质（9.05Wh L-1）的1.35V N-2-克里思/（NPr）（2）V AORFB提供114 mW cm（-2）的高功率密度和在60 mA cm（-2）下400次循环的100%容量保持率。在1.0 m电解质浓度下，N-2-克里思/（NPr）（2）V AORFB在60 mA cm（-2）下实现了18.1 Wh L-1的能量密度和90%的400次循环的容量保持率。
Aqueous organic redox flow batteries (AORFBs) are highly attractive for large-scale energy storage because of their nonflammability, low cost, and sustainability. (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO) derivatives, a class of redox active molecules bearing air-stable free nitroxyl radicals and high redox potential (>0.8 V vs NHE), has been identified as promising catholytes for AORFBs. However, reported TEMPO based molecules are either permeable through ion exchange membranes or not chemically stable enough for long-term energy storage. Herein, a new TEMPO derivative functionalized with a dual-ammonium dicationic group, N-1, N-1, N-1, N-3, N-3, 2, 2, 6, 6-nonamethyl-N-3-(piperidinyloxy)propane-1,3-bis(ammonium) dichloride (N-2-TEMPO) as a stable, low permeable catholyte for AORFBs is reported. Ultraviolet-visible (UV-vis) and proton nuclear magnetic resonance (H-1-NMR) spectroscopic studies reveal its exceptional stability and ultra-low permeability (1.49 x 10(-12) cm(2) s(-1)). Coupled with 1,1 '-bis[3-(trimethylammonio)propyl]-4,4 '-bipyridinium tetrachloride ((NPr)(2)V) as an anolyte, a 1.35 V N-2-TEMPO/(NPr)(2)V AORFB with 0.5 m electrolytes (9.05 Wh L-1) delivers a high power density of 114 mW cm(-2) and 100% capacity retention for 400 cycles at 60 mA cm(-2). At 1.0 m electrolyte concentrations, the N-2-TEMPO/(NPr)(2)V AORFB achieves an energy density of 18.1 Wh L-1 and capacity retention of 90% for 400 cycles at 60 mA cm(-2).