"Wine-Dark Sea" in an Organic Flow Battery: Storing Negative Charge in 2,1,3-Benzothiadiazole Radicals Leads to Improved Cyclability
"Wine-Dark Sea" in an Organic Flow Battery: Storing Negative Charge in 2,1,3-Benzothiadiazole Radicals Leads to Improved Cyclability
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DOI：
10.1021/acsenergylett.7b00261
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发表时间：
2017-05-01
影响因子：
22
通讯作者：
Wei, Xiaoliang
中科院分区：
文献类型：
--
作者：
Duan, Wentao;Huang, Jinhua;Wei, Xiaoliang
氧化还原活性有机材料在氧化还原液流电池中显示出巨大的应用前景，但在非水体系中，当氧化还原活性物质浓度不变时，通常会遇到循环效率和稳定性有限的问题。本文报道了一种新的杂环有机阳极液分子2，1，3-苯并噻二唑，它具有高溶解度、低氧化还原电位和快速的电化学动力学。与基准阴极只读存储器相结合，非水有机流动电池与最先进的非水系统相比，在可循环氧化还原材料浓度和电池效率方面显示出显著改善。特别是，该体系在较高的ROM浓度(>；0.5M)下具有较高的循环性和相对稳定的效率和容量，这归因于2，1，3-苯并噻二唑阴离子中高度离域的电荷密度，导致了良好的化学稳定性。这种材料的发展代表着朝着有希望的下一代能量存储取得的重大进展。
Redox-active organic materials (ROMs) have shown great promise for redox flow battery applications but generally encounter limited cycling efficiency and stability at relevant redox material concentrations in nonaqueous systems. Here we report a new heterocyclic organic anolyte molecule, 2,1,3-benzothiadiazole, that has high solubility, a low redox potential, and fast electrochemical kinetics. Coupling it with a benchmark catholyte ROM, the nonaqueous organic flow battery demonstrated significant improvement in cyclable redox material concentrations and cell efficiencies compared to the state-of-the-art nonaqueous systems. Especially, this system produced exceeding cyclability with relatively stable efficiencies and capacities at high ROM concentrations (>0.5 M), which is ascribed to the highly delocalized charge densities in the radical anions of 2,1,3-benzothiadiazole, leading to good chemical stability. This material development represents significant progress toward promising next-generation energy storage.