Thienoviologen anolytes for aqueous organic redox flow batteries with simultaneously enhanced capacity utilization and capacity retention

Abstract

A series of thienoviologen derivatives ([(NPr)2TV]Cl4, [(OHPr)2TV]Cl2) with narrow bandgap high solubility and double electron transfer properties as anolyte for high performance aqueous organic redox flow batteries (AORFBs) is reported....

Robust Chalcogenophene Viologens as Anolytes for Long-Life Aqueous Organic Redox Flow Batteries with High Battery Voltage

“…The synthetic route and data of 2 are given in a previously reported reference. 59 The Fouriertransform infrared spectroscopy data of 1, 2, and 3 are shown in Figure S36. The photophysical characteristics of chalcogenophene viologens are given in Figures S4−S10 and Tabe S1.…”

“…Nuclear magnetic resonance (NMR) and human resource management system (HRMS) data of 1 , 3 are all given in the Supporting Information. The synthetic route and data of 2 are given in a previously reported reference . The Fourier-transform infrared spectroscopy data of 1 , 2 , and 3 are shown in Figure S36.…”

“…For two-electron storage, the phenyl-bridged viologen derivatives showed a one-step two-electron, lower single redox potentials (<−0.7 V vs SHE), and comparable fade rates per cycle, which is a breakthrough in the application of viologen derivatives to AORFBs. ,− In addition, the introduction of π-conjugated groups can also reduce the redox potential while enhancing the open-circuit voltage and current density of the battery, which are all crucial for the practical application of AORFBs. Recently, our research group found that thiophene viologens can improve the capacity utilization rate and capacity retention rate of the battery at the same time and obtain a good battery performance . This important finding prompted us to further investigate other heteroarene-fused viologens consisting of furan and selenophene as anolytes for AORFBs.…”

“…Recently, our research group found that thiophene viologens can improve the capacity utilization rate and capacity retention rate of the battery at the same time and obtain a good battery performance. 59 This important finding prompted us to further investigate other heteroarene-fused viologens consisting of furan and selenophene as anolytes for AORFBs. We envisioned that the comparison of these derivatives would provide crucial insights into the factors that govern the electrochemical properties as well as the impact of the performance of the AORFBs.…”

Highly Soluble Arylene Diimide Derivatives as Anolyte Materials with Two-Electron Storage for Ultrastable Neutral Aqueous Organic Redox Flow Batteries

“…41 In recent years, some research groups have made many efforts to expand the conjugated structure and electron delocalization of viologen by introducing electron donor groups, such as thiazolo [5,4-d]thiazole, 42 phenyl, 43 and thiophene. 44 The results proved that this strategy effectively stabilized the highly reduced species. However, the capacity retention is still less than 90% in 300 cycles, which is due to the pyridinium rings changing from aromaticity [NICS(1) = -9.28] to antiaromaticity [NICS(1) = 2.73], resulting in the decline of stability.…”