Energy Material Advances
·
2021
·
IF 0
Shuzhi Hu,Liwen Wang,Xianzhi Yuan,Zhipeng Xiang,Mingbao Huang,Peng Luo,Yufeng Liu,Zhiyong Fu,Zhenxing Liang
A novel electroactive organic molecule, viz., 1-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)-1′-(3-(trimethylammonio)propyl)-4,4′-bipyridinium trichloride ((TPABPy)Cl3), is synthesized by decorating 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) with viologen, which is used as the positive electrolyte in neutral aqueous redox flow battery (ARFB). Extensive characterizations are performed to investigate the composition/structure and the electrochemical behavior, revealing the favorable effect of introducing the cationic viologen group on the electroactive TEMPO. Salient findings are as follows. First, the redox potential is elevated from +0.745 V for TEMPO to +0.967 V for decorated TEMPO, favoring its use as the positive electrolyte. Such an elevation originates from the electron-withdrawing effect of the viologen unit, as evidenced by the nuclear magnetic resonance and single crystal structure analysis. Second, linear sweep voltammetry reveals that the diffusion coefficient is 2.97×10−6 cm2 s−1, and the rate constant of the one-electron transfer process is 7.50×10−2 cm s−1. The two values are sufficiently high as to ensure low concentration and kinetics polarization losses during the battery operation. Third, the permeability through anion-exchange membrane is as low as 1.80×10−11 cm2 s−1. It is understandable as the positive-charged viologen unit prevents the molecule from permeating through the anion exchange membrane by the Donnan effect. Fourth, the ionic nature features a decent conductivity and thus eliminates the use of additional supporting electrolyte. Finally, a flow battery is operated with 1.50 M (TPABPy)Cl3 as the positive electrolyte, which affords a high energy density of 19.0 Wh L-1 and a stable cycling performance with capacity retention of 99.98% per cycle.
研究领域:
化学
·
能源科学
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DOI
JOURNAL OF MOLECULAR LIQUIDS
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2019
·
IF 4.561
Yanxing Zheng,Jiwei Wang,Xinqiao Tang,Lei Zhang,Fanbao Meng
Viologen-based ionic liquid crystals (VILCs) bearing viologen cations and various counter anions (Br − 1 , CsO − , PF 6 − 1 , CF 3 COO − , TsO − , and BF 4 − 1 ) were prepared using cholesterol, bromobutanoyl chloride, bipyridine and different anionic salts. The chemical structures and the SmC ⁎ phase were identified, and the effect of different anions on both liquid crystalline behavior and ferroelectric property was investigated. Melting temperatures of these VILCs with different anions were similar, but SmC*-isotropic phase transition temperatures were elevated in sequence of TsO − , CsO − , CF3COO − , PF6 − , Br − and BF4 − . They showed different polarization values changed from −9.1 to 9 nC/cm 2 as the electric field changed from −10 V to 10 V. The ferroelectric parameters ± E c , ± P r , and ± P s changed a little due to the different counter anions. The VILC with BF 4 − anion showed the optimal ferroelectric properties in these VILCs series. Unlike conventional ferroelectric liquid crystals, the VILCs displayed asymmetry in the hysteresis loops due to formation of double electrical layers in the ordered SmC ⁎ phase.
研究领域:
材料科学
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物理化学
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2025
·
IF 4.7
Zhao-Hao Li,Ke Zheng,Yuan-Meng Yue,Ya-Meng Li,Bang-Tun Zhao
Viologen-functionalized materials have broad and desirable application prospects. Nowadays, synthesis of such materials and exploration of their new properties still remain a great challenge. In this work, one viologen-functionalized crystalline material, {[Cd(bcbpy)(tdc)(H 2 O)](0.5DMF)} n (bcbpy =1-(4-carboxybenzyl)-4,4′-bipyridinium, H 2 tdc = 2,5-thiophenedicarboxylic acid) has been constructed by solvothermal methods. The material features an interesting two-dimensional layered structure constructed from tdc 2– ligands, which is decorated with bcbpy ligands. Due to the presence of electron-deficient viologen moieties, the crystalline sample displays a reversible photochromic behavior driven by photo-induced electron transfer under irradiation of UV light within a short time. Curiously, the ground sample after mechanical grinding exhibits a different photochromic behavior. Moreover, photo-regulated luminescence properties of the material before and after mechanical grinding have also been studied.
研究领域:
化学
·
材料科学
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产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2021
·
IF 7.267
Zhen-Jie Huang,Feng Li,Jia-Ping Xie,Hong-Rong Mou,Cheng-Bin Gong,Qian Tang
The design and synthesis of broad absorption electrochromic materials (ECMs) that modulate visible and near infrared light are important for energy-saving smart windows . Most studies on broad absorption ECMs have focused on transition metal oxides , organic polymers and small organic molecules based on triarylamines, while studies on viologen analogues are scarce. In the current study, two tetra-substituted viologen analogues 4,4′,4″,4‴-(benzene-1,2,4,5-tetrayl)- tetrakis(1-butylpyridin-1-ium) (BTTBP) and 1,1,2,2-tetrakis(4-(1-butyl-pyridin-4-yl)- phenyl)ethane (TBPPE) were prepared by introducing benzene and tetraphenylethylene with large conjugation degrees as parent moieties. Compared with the conventional viologen 1,1′-dibutyl-(4,4′-bipyridine)-1,1′-diium without a conjugated parent, BTTBP and TBPPE exhibited high electrochromic performance and broad absorption to the near infrared region . TBPPE in particular exhibited excellent broad absorption electrochromic behavior with high optical contrast (63% at 733 nm and 46% at 997 nm), distinct color change (pale yellow to yellow-green to black-green), good cycling stability (attenuation in optical contrast of 1% after 1000 cycles at 733 nm) and excellent coloration efficiency (251 cm 2 /C) in the near infrared region. These findings provide a strategy for designing high-performance cathode broad absorption ECMs and a promising candidate for energy-saving smart windows.
研究领域:
材料科学
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能源技术
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Hu Luo,Gongwei Wang,Juntao Lu,Lin Zhuang,Li Xiao
In this work, we report a novel dual-redox electrochemical capacitor (EC) using a modified viologen (V) as anolyte and bromide (Br) as catholyte. In general, modified viologens are dications. When they are used as anolyte in aqueous dual-redox ECs, only one-electron reduction reaction can occur, because most divalent and monovalent viologens are soluble but zerovalent viologens are insoluble. The insoluble and nonconductive zerovalent viologens will block the surface of the activated carbon electrode from subsequent reactions. The energy densities of the dual-redox ECs using viologens are expected to be greatly improved if those viologens can carry out multiple electron reduction reactions. In this work, 1,1′-bis[3-(trimethylammonio)propyl]-4,4′-bipyridinium (NV4+), a tetra-cationic viologen, has been used as anolyte for dual-redox EC. NV2+ produced by two-electron reduction of NV4+ is highly soluble in aqueous solution, so that two consecutive one-electron reductions of viologen can be utilized in dual-redox ECs. To further solve the cross-diffusion issue of the charging products, Br3− and NV cations, of the positive and the negative electrodes, we have used tetrapropyl ammonium cation (TPA+) to complex Br3–, and quaternized styrene ethylene butylene styrene (SEBS-QA) anion exchange membrane (M) to block the cross-diffusion of NV cation. The obtained NV/TPA/Br-M (NV4+/TPA+/Br– electrolyte with SEBS-QA membrane) dual-redox EC exhibits an average Coulombic efficiency over 99%. It also provides a high specific energy of 87 Wh/kgdry at 1 A/gdry and a peak power density of 4.8 kW/kgdry at 5 A/gdry. The functions of TPA+ and SEBS-QA membrane were characterized and are discussed in detail.
研究领域:
材料科学
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电化学
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能源存储
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2026
·
IF 7.8
Lv Zekuo,Zhang Leipeng,Xu Lei,Zhang Yike,Wang Yuqiang,Jiang Qiumei,Zhao Miaomiao,Yang Rui,Han Xingcan,Liu Dongqi,Zhao Jiupeng,Li Yao
Black electrochromic devices (ECDs) that offer broadband visible-light absorption and a visually neutral dark state are highly attractive for smart windows, displays, and adaptive light-management systems. However, achieving high-quality black electrochromism with high optical contrast, fast switching, and long-term cycling stability remains challenging, primarily owing to the unbalanced spectral absorption and radical-cation dimerization issues inherent in conventional viologen-based systems. Herein, we address the limitations of conventional viologen-based electrochromic devices via a strategy integrating molecular design and spectral superposition engineering. A fluorinated benzyl viologen derivative, 1-(4-fluorobenzyl)–1 ′ -(3,5-bis(trifluoromethyl)benzyl)–4,4 ′ -bipyridinium di(tetrafluoroborate) (TFBV), is designed to suppress radical-cation aggregation and improve redox stability. To compensate for the weak absorption of TFBV in the 450–550 nm region, a cyanophenyl-substituted viologen (1,1 ′ -bis(4-cyanophenyl)–4,4 ′ -bipyridinium bis(tetrafluoroborate) (CPV)) with extended π-conjugation is introduced as a complementary chromophore, enabling red-shifted and balanced visible-light absorption. Benefiting from the synergistic absorption of TFBV and CPV, the optimized ECD exhibits a high bleached-state transmittance of 81.1%, a low colored-state transmittance of 5.2%, and a large optical contrast of 75.9% across the visible region. The device also shows rapid switching with coloration and bleaching times of 4.4 and 4.1 s, respectively, a high coloration efficiency of 218.65 cm 2 C –1 , and excellent cycling stability with 99.8% contrast retention after 10,000 cycles. Furthermore, a prototype smart window based on TFBV/CPV exhibits effective light and heat regulation. This work presents an effective molecular design strategy for stable, fast-response black ECDs and expands the potential of viologen-based materials for energy-saving smart windows.
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DOI
PubMed
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Jiaqi Xu,Zhoulin Ye,Zongcai Deng,Dongchu Chen,Qilang Lin,Dongyang Chen
Polymer batteries have attracted increasing attention because of their advantages of good flexibility, high compatibility with organic electrolytes, and high environmental friendliness. However, the low utilization rate of the redox-active units buried in polymeric network and the slow kinetics of the electrochemical reactions hinder their development. Herein, mono- and diviologen functionalities are attached to a tetramethylbiphenol-derived poly(arylene ether ketone) (TPAEK) by postmodification to yield two redox-active polymers MV-TPAEK and 2MV-TPAEK, respectively, and polymer electrodes are prepared by mixing them with N-doped carbon nanotubes without binders. When paired with the Li counter electrode, the MV-TPAEK and 2MV-TPAEK electrodes deliver specific discharge capacities of 93.3 and 95.4 mA h g–1, respectively, at a current rate of 0.1 C and maintain 36.1 and 42.3 mA h g–1, respectively, after 100 galvanostatic cycles. When the current rate is increased to 10 C, the specific discharge capacities are lowered to 13.9 and 25.8 mA h g–1, respectively, for the MV-TPAEK and 2MV-TPAEK electrodes due to the increased electrochemical polarizations. All of these results prove that the 2MV-TPAEK electrode is better than the MV-TPAEK electrode. When the counter electrode is changed to Na, the trend remains the same. Given the fact that the two polymers have an identical backbone, the improved electrochemical performance of 2MV-TPAEK may be ascribed to the larger mobility of the extended 2MV pendant, which is beneficial for the formation of more molecular voids and stacked intermediate structures for better charge transfer. This study paves the way for the molecular design of redox-active polymers for high-performance polymer batteries.
研究领域:
材料科学
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电化学
·
高分子化学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Jinxu Zhao,Qijun Chen,Ying Zhou,Jianming Zheng,Chunye Xu
The poor electrochemical reversibility of the dimers limits the application of viologens in aqueous electrochromic devices (ECDs). Here, we report a tetramethyl viologen, 2,2′,6,6′-tetramethyl-4,4′-bipyridine hydrobromide ([MVH][Br]), in which tetramethyl substitution provides significant steric hindrance to prevent dimerization. Our experiments show that this designed viologen performs excellently in an aqueous solvent, including excellent color variation, optical modulation, cycling stability, and radical inertness. Typically, an aqueous ECD fabricated with the viologen is able to retain 95.48% of its optical modulation after 5000 cycles. Furthermore, we found that this viologen is impervious to UV polymerization. Based on this property, we demonstrate a bichromatic ECD based on a hydro-ionic hybrid gel using in situ UV polymerization. This study not only extends the application of viologens in aqueous ECDs but also paves the way for the future development of high-mechanical-performance hydrogel-based ECDs.
研究领域:
材料科学
·
电化学
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产品关联
DOI
PubMed
高影响因子
Advanced Materials Technologies
·
2023
·Vol. 8
·期 22
·2301028
·
IF 6.8
Liangliang Wu,Huajing Fang,Jiaqi Li,Lingqi Wu,Hong Wang
Viologen-based electrochromic devices have attracted great attention because of their tremendous potential in building energy conservation and low power display. However, the unsatisfactory performance at lower voltage limits their application, while the high driving voltage increases the energy consumption as well as safety risk. Herein, an electrocatalytic strategy is proposed for high-performance viologen-based electrochromic devices. Copper oxide (CuO x ) nanoparticles are uniformly deposited on the F-doped Tin Oxide (FTO) glass for enhancing the catalytic activity of Br − /Br 3 − redox couple, thereby promoting the interfacial charge transfer. The driving voltage can be reduced by ≈30% without sacrificing its high transparency (up to 80%) and the cycling stability can be significantly improved within 200 cycles. Large-area smart windows and electrochromic displays are fabricated, which can be driven by the 1.5 V dry battery. This work opens up a new path to optimize the electrochromic performance of viologens and also lays the foundation for the application of catalysis in optoelectronic devices.
研究领域:
材料科学
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能源技术
·
光学工程
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产品关联
DOI
高影响因子
IONICS
·
2026
·
IF 3.4
Zhao Jinsong,Wu Xiangyong,Song Ying,Su Hao,Song Weixing
Viologen has become a prominent focus of research in electrochromism due to its facile molecular structure modification, diverse color transitions, low driving voltage, and high coloration efficiency. In this study, asymmetric viologen derivatives (Pentyl-V and Heptyl-V) were synthesized through N-alkylation reactions using 1,2-bis(4-pyridyl) ethylene as the pyridine backbone. Subsequently, these derivatives were used to fabricate electrochromic gels, which were integrated with ITO-coated conductive glass to assemble electrochromic devices. Finally, the spectroelectrochemical, and electrochromic properties of the devices were comprehensively studied. Among these two electrochromic devices based on asymmetric viologen derivatives, the viologen derivative Heptyl-V, which has a longer alkyl chain substituent, demonstrates a significant optical contrast (30.3%) at 521 nm, a fast response time (coloring/ bleaching time of 21.1 s and 4.9 s), and a satisfactory coloring efficiency (180.4 cm²/C). The gel electrochromic device, based on asymmetric viologen derivatives, offers advantages such as a simple preparation process, low energy consumption, and high coloring efficiency. It holds potential for application in fields such as smart windows, electrochromic displays, and wearable electronics.
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产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2024
·
IF 6.3
Haibo Wu,Fangyuan Sun,Chengwei Jiang,Fengyu Su,Yanqing Tian,Yan Jun Liu
In this study, three novel monoheptyl-substituted extended viologens ( EDOT-C7 , O-C7 , and BTD-C7 ) were synthesized by introducing ethylenedioxythiophene, furan, and benzothiadiazole moieties between the two pyridine rings as the chromophores, respectively. Their all-in-one ECDs were prepared, which were named ECD-EDOT , ECD-O and ECD-BTD , respectively. The devices’ performance was investigated systematically, including electrochemical properties, photoelectric properties and electrochromic properties. Due to the different electronic properties of the chromophores, the devices exhibited different colored states, including orange ( ECD-EDOT ), magenta ( ECD-O ) and blue-violet ( ECD-BTD ). All the devices exhibit good coloration efficiency of 71.1 cm 2 /C ( ECD-EDOT ), 107.7 cm 2 /C ( ECD-O ) and 91.6 cm 2 /C ( ECD-BTD ). In addition, the devices displayed relatively high optical contrast and cycling stability. The optical contrast of ECD-EDOT , ECD-O and ECD-BTD reached 62.3 %, 71.1 % and 70.0 %, respectively. Among them, ECD-BTD exhibited the most excellent stability, which retains 82.0 % optical contrast of its initial state after continuous 1000 working cycles. Additionally, a variety of multicolor (including blue, black, brown, and red, etc) electrochromic devices based on the synthesized monoheptyl-substituted extended viologen ( O-C7 ) and a reported diheptyl viologen ( DHBP ) have been successfully obtained by the regulation of the molar ratios of the two chosen compounds, which shows the bright application prospect of mono-substituted extended viologen in the multicolor electrochromic field.
研究领域:
材料科学
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电化学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
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2022
·
IF 5.122
Yuewei Zhang,Xuchao Jin,Weiran Zhang,Chang Gu,Xuesong Liu,Yu-Mo Zhang
A bistable electrochromic device based on poly(viologen)s is demonstrated with good overall performance, including bistability (4981 s), switch-on voltage (−1.0 V) and reversibility (≥1000 cycles). Overall, these results imply that the control of the diffusivity of viologens is an effective methodology for achieving excellent bistability and low energy consumption.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）