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

doi:10.21203/rs.3.rs-1760418/v1

PDF

Article

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

https://doi.org/10.21203/rs.3.rs-1760418/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted 01 Jul, 2022

You are reading this latest preprint version

Two-electron neutral aqueous organic redox flow batteries (AORFBs) hold more promising applications in the power grid than one-electron batteries because of their higher capacity. However, their development is strongly limited by the structural instability of the highly reduced species. By combining the extended π-conjugation structure of the anolytes and the enhanced aromaticity of the highly reduced species, we reported a series of highly water-soluble and inexpensive arylene diimide derivatives (NDI, PDI, TPDI) as novel two-electron storage anolyte materials for ultrastable AORFBs. Matched with (ferrocenylmethyl)trimethylammonium chloride (FcNCl) as catholyte, arylene diimide derivative-based AORFBs showed the highest stability in two-electron AORFBs to date. The NDI/FcNCl-based AORFB delivered 98.4% capacity retention at 40 mA cm^− 2 for 350 cycles, and TPDI/FcNCl-based AORFB showed remarkable stability (1600 cycles) with 95.5% capacity retention at 20 mA cm^− 2. This finding lays the theoretical foundation and offers a reference for improving the stability of two-electron AORFBs.

Organic flow battery

anolyte materials

arylene diimide derivatives

ultrastable

two-electron storage

Currently, the imbalance between energy supply and demand has become increasingly prominent in the process of global economic development.^1–3 Therefore, improving the storage and utilization efficiency of new energy (wind or solar) has attracted much attention.^4,5 Flow batteries stand out in large-scale storage technology and have been applied to electricity grids due to the decoupled energy and power, scalability (up to MW/MWh), and security.^6–8 Among them, neutral aqueous organic redox flow batteries (AORFBs) are expected to become the leader in next-generation energy storage and conversion devices, resulting from their high conductivity, safety, flexibility, environmental friendliness, and low cost.^9–13 Electrolyte materials are the key points for neutral AORFBs.^13–15 The energy source of existing electrolyte materials mainly relies on variable valence states such as C = O, C = N, N = O and metals. The active materials, including arylene diimides,^16,17 quinones,^18,19 viologens,^20–22 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO),^23–26 ferrocenes,^27–30 etc.,^31–33 have excellent redox properties and high water solubility and are very suitable for neutral AORFBs.

Viologen has been widely used as an electrolyte material for neutral AORFBs.^34–39 Viologens are mostly used for one-electron storage due to the lack of stability of highly reduced species.⁴⁰ Therefore, improving the effective electron utilization and stability of viologen has become an important challenge in the application of neutral AORFBs.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. Therefore, it is necessary to develop a new electrolyte material with a more stable structure for highly reduced species to achieve efficient two-electron storage stability.

Arylene diimide derivatives have more conjugated planar rigid structures than viologens, including strong π-π conjugation and weak p-π conjugation, which are beneficial for promoting redox activity and electron transfer.⁴⁵⁻⁴⁸ In different redox states, these derivatives maintain good aromaticity and high stability.⁴⁹ Moreover, their excellent photoelectrochemical properties, such as two-electron transfer, strong visible light absorption, photostability, and thermal stability, make them widely used in organic batteries,⁵⁰⁻⁵³ pseudocapacitors,⁵⁴ optoelectronic devices,⁵⁵ biosensing,⁵⁶ and other applications. Recently, arylene diimide derivatives have also been used as electrolyte materials for flow batteries.⁵⁷⁻⁵⁹ Jin and coworkers reported an all-polymer particulate slurry redox flow battery (APPSB) using a microsized and uniformly dispersed all-polymer particulate suspension. The discharge capacity retention after 300 cycles was 70% of the initial capacity, and the capacity utilization was only a poor value of 9.23%.⁶⁰ Byon and coworkers demonstrated a potassium salt of N, N’-bis(glycinyl)naphthalene diimide [K₂-BNDI], which showed a poor solubility of 30 mM in water. 0.025 M [K₂-BNDI]/4-OH-TEMPO AORFB delivered 83.2% capacity retention at 5 mA cm^− 2 in 100 cycles.⁶¹ The results indicated that the existing arylene diimide-based electrolytes have certain two-electron transfer properties. However, they still have many challenges, such as insufficient stability and poor water solubility. It can be envisioned that the extension of the π-conjugated structure and the decoration of more hydrophilic groups with large sizes into hydrophobic arylene diimide derivatives, such as different numbers (2 ~ 6) of hydrophilic ammonium cation groups, should significantly enhance the structural stability as well as increase the solubility of the active materials. This method would improve the charge repulsion between the pendent ammonium groups, prevent the dimerization degradation process, and inhibit electrolyte penetration.

Based on these considerations, a series of inexpensive and high-yield quaternary ammonium salt-containing arylene diimide derivatives (NDI, PDI, and TPDI) with high solubility, narrow bandgap, and stable π-conjugate structure were synthesized as anolytes for AORFBs. The DFT results also showed that the aromaticity of arylene diimide derivatives were further enhanced from oxidized to highly reduced species. The larger molecular size achieved zero penetration (for 30 days). Using FcNCl as the catholyte, this work delivered excellent ultrastability for two-electron storage with a low daily decay, and Coulombic efficiency close to 100%. Compared with previous work, this work demonstrated much better battery performance, which was the most stable system for two-electron storage.

Synthesis and Structure Characterization

To achieve the designed arylene diimide derivatives, NDI, PDI, and TPDI, a two-step method was used according to the previous literature (Scheme 1).^62,63 First, 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTDA) and 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) underwent a ring-opening reaction and reacted with an amino group to form amides and further to obtain imides by the closed-loop reaction. Then, methyl chloride or methyl iodide was introduced to produce highly hydrophilic naphthalene diimide (NDI) and perylene diimide (PDI, TPDI) via ionization. Among them, the solubility of NDI in 2 M NaCl solution is as high as 1.00 M, corresponding to a theoretical capacity of 53.6 Ah L^− 1. When only expanding the conjugation, the solubility of PDI is only 0.08 M. When further improving solubility by introducing more hydrophilic ammonium cation groups to prepare TPDI, its solubility (0.14 M) was approximately twice that of PDI (Figure S1). The solubility and capacity information of NDI/PDI/TPDI are summarized in Table S1. The molecular structures were verified by NMR and HRMS. The experimental and calculated values of UV–Vis were consistent (Figures S6-S9). Compared with NDI (3.10 eV), the absorption of PDI (2.02 eV) and TPDI (2.01 eV) showed a narrower bandgap, an obvious redshift, and wider absorption in the visible region.

Electrochemical Characterization

The electrochemical properties of NDI/PDI/TPDI redox couples were characterized by cyclic voltammetry (CV) (Figs. 1a and S2). Figure. 1b shows the structural changes of the arylene diimide derivatives during the redox process. NDI shows an obvious two-electron platform at E¹_1/2 = -0.09 V (NDI²⁺ ↔ NDI^1+●), E²_1/2 = -0.46 V (NDI^1+● ↔ NDI⁰). PDI also presents two quasi-reversible redox potentials at E¹_1/2 = -0.13 V (PDI²⁺ ↔ PDI^1+●), E²_1/2 = -0.45 V (PDI^1+● ↔ PDI⁰). TPDI shows two one-electron oxidation peaks and one two-electron reduction peak with redox potentials of E¹_1/2 = -0.17 V (TPDI⁶⁺ ↔ TPDI^5+●), E²_1/2 = -0.35 V (TPDI^5+● ↔ TPDI⁴⁺), respectively, due to the overlap of the 1st and 2nd electron reductions. The redox potentials of PDI and TPDI are significantly lower than that of NDI. The potential difference between the two redox peaks of NDI/PDI/TPDI gradually decreased from 0.37 V to 0.32 V to 0.18 V, respectively, which is attributed to the increased conjugation and more electron-withdrawing groups. The peak current intensity of NDI is significantly higher than that of PDI and TPDI, which is caused by the solubility difference. The better the solubility of the electrolyte, the lower the viscosity, so that the conductivity is enhanced, and the number of effective charge transfers is increased. Paired with FcNCl as the catholyte (0.61 V), the NDI/FcNCl-, PDI/FcNCl-, TPDI/FcNCl-based AORFBs delivered 1.07 V, 1.06 V, and 0.96 V battery voltage, respectively, making them ideal candidates as anolytes to improve the energy density of batteries in terms of output voltage. At different scanning rates, NDI/PDI/TPDI showed good CV curves, and the trend of redox peaks is consistent, implying its excellent redox reversibility and stability.

Electrochemical Kinetic Characterization

Linear sweep voltammetry (LSV) was used to study the electrochemical kinetic characteristics of NDI/PDI/TPDI (Figure S3-S5). The diffusion coefficient (D) and electron transfer constant (k₀) for the first reduction process are 1.96 × 10^− 7, 3.21 × 10^− 8, and 2.87 × 10^− 7 cm² s^− 1 and 5.74 × 10^− 5, 3.93 × 10^− 5, and 2.42 × 10^− 4 cm s^− 1, respectively. For the second reduction process, D and k₀ are 3.51 × 10^− 7, 2.75 × 10^− 7, 3.34 × 10^− 6 cm² s^− 1 and 2.06 × 10^− 5, 1.05 × 10^− 4, 7.29 × 10^− 4 cm s^− 1 transfer constant of NDI/PDI/TPDI are high enough to operate flow batteries with low concentrations and kinetic polarization losses.

Density Functional Theory Calculations

Density functional theory (DFT) calculations were finally implemented to confirm the conformation of the oxidized NDI²⁺, PDI²⁺, TPDI⁶⁺, and reduced NDI⁰, PDI⁰, TPDI⁴⁺ (Fig. 2a). The oxidized NDI²⁺, PDI²⁺, and TPDI⁶⁺ (eigenstate) demonstrate excellent aromaticity, with astrong π-conjugated rigid planar skeleton and narrow bandgaps of 5, 2.45, and 2.43 eV, respectively. After gaining two electrons, the electron transfer channel of the eigenstate is broken, and a new π-π conjugated plane is formed. The bandgaps are 2.59, 2.48, and 2.46 eV, respectively, which are conducive to the rapid electron transfer of the electrolytes. One likely explanation for the unusual stability of arylene diimide derivatives is aromaticity. The NICS(1) results lead to the same conclusions (Fig. 2b). For 1,1`-bis[3-(trimethylammonio)-propyl]-4,4`-bipyridinium tetrachloride [(NPr)₂V]Cl₄, the two pyridinium rings of [(NPr)₂V]⁴⁺ are aromatic (negative NICS values), but there are nonaromatic in [(NPr)₂V]²⁺. This aromatic transition from − 18.56 to 5.46 may be an important reason for the instability of [(NPr)₂V]Cl₄ during two-electron storage. In NDI²⁺, the central naphthalene ring is aromatic [NICS(1) = -9. 98], and the diimide rings are nonaromatic [NICS(1) = 0.67]. In NDI⁰, all the rings become aromatic [NICS(1) = -2.22, -5.94]. In PDI²⁺, the central ring is slightly antiaromatic [NICS(1) = 1.31], the peripheral rings that form the two naphthalene cores are aromatic [NICS(1) = -8.06], and the diimide rings are nonaromatic [NICS(1) = -0.09]. In PDI⁰, all rings are aromatic [NICS(1) = -9. 80, -4.45, -5.35]. The results for TPDI are very similar to those for PDI. The total NICS(1) values showed that the order of their aromaticity is TPDI ≈ PDI > NDI > [(NPr)₂V]Cl₄, corresponding to molecular stability. Moreover, their molecular volumes are calculated as 574.93, 712.74, and 1068.72 Å³, which is beneficial for inhibiting the penetration of electrolytes. The permeability of the electrolyte for the anion-exchange membrane (Selemion AMV) was tested by H-tube for 30 days, and no obvious color and concentration changes by UV–Vis spectroscopy were found in the blank solution, indicating that no crossover occurred (Figure S10). Another important reason may be the presence of intermolecular hydrogen bonding and intrinsic π-π stacking interactions, which further increase the electrostatic interactions between molecules and thus hinder the shuttling of electrolytes.

In situ UV Spectra

The in situ UV spectra were adopted to clarify the two-electron transfer process and switchable conjugation mechanism of these full batteries (Figs. 4). By applying different voltages, the UV–Vis spectra of different molecular states were recorded (Fig. 3a). For NDI (300–700 nm), the initial absorption of NDI²⁺ tends to be in the ultraviolet region, mainly at 362 and 381 nm. With an applied potential of 0.81 V, NDI²⁺ gains an electron and rapidly forms the radical species NDI^1+●. The absorption of the visible light region is greatly redshifted, and a wide single peak is generated at 448 nm. The color of the anolyte changes from colorless to yellow. When the voltage is continuously increased to 0.92 V, NDI^1+● gains the second electron, forming reduced NDI⁰. The absorption is enhanced at 402, 526, and 568 nm, and the color of the anolyte becomes light red. PDI and TPDI adopt the same test methods. Compared with NDI, the visible light absorption of PDI and TPDI shows an obvious redshift, which may be caused by the increase in conjugation. The absorption of the oxidized state PDI²⁺ (light red) in the visible region is mainly located at 488 nm and 553 nm. When the voltage increases to 0.93 V, the radical species PDI^1+● (blue–purple) redshifts to 543 nm and 623 nm. When the voltage increases to 1.05 V, the absorption of reduced PDI⁰ (purplish red) increases sharply at 510 nm, 532 nm, and 601 nm. Compared with PDI, TPDI has slight changes in absorption in the visible region and color change due to the consistent structure. The absorption of the oxidized state TPDI⁶⁺ (pink) is mainly at 500 nm and 544 nm in the visible region. When the voltage increases to 0.85 V, the main absorption peak of the radical species TPDI^5+● (blue) is at 586 nm, and the absorption of reduced TPDI⁴⁺ (purplish red) is significant at 508 nm, 539 nm, and 605 nm when the voltage increases to 0.92 V. The color change of NDI/PDI/TPDI during the charging process resembles chemical reduction with Zn. Simultaneously, the radical characteristics of radical species were evaluated by electron paramagnetic resonance (EPR) spectroscopy (Fig. 3b). NDI^1+●, PDI^1+●, and TPDI^5+● have expected g-factor values of 2.0032, 2.0028, and 2.0027, respectively, supporting the organic nature of the radicals. Furthermore, the in situ UV spectrogram of NDI/PDI/TPDI was monitored in real time during charging and discharging (Figs. 4c, 4d, S11, and S12).

Full Battery Tests

A series of full batteries with two-electron storage were assembled for demonstration. NDI/PDI/TPDI are used as an anolyte (two-electron transfer), paired with highly water-soluble and stable FcNCl (one-electron transfer), an established catholyte material for AORFBs. The electrolytes are dissolved in 2 M NaCl supporting electrolyte, making the entire solution more conductive. Selemion AMV has high ion selectivity, allowing only Cl⁻ to pass through, and cations are forbidden to the shuttle. The maximum redox potentials of NDI/PDI/TPDI/FcNCl are − 0.46 V, -0.45 V, -0.35 V and 0.61 V, respectively. These potentials are within the water splitting window (HER at -1.0 V and OER at 1.5 V) and can ensure the normal test environment of the battery. On the anolyte side, the diimide derivatives undergo a two-step one-electron redox reaction accompanied by keto–enol tautomerism and the formation of a quinone structure. On the catholyte side, FcNCl performs a one-electron redox reaction from Fe²⁺ to Fe³⁺.

The NDI/FcNCl-based AORFB was constructed with 0.1 M NDI and 0.1 M FcNCl for the anolyte and catholyte (theoretical capacity of 42.88 mAh), respectively. The cell delivers outstanding stability during 350 cycles at a 40 mA cm^− 2 current density with 34.9 mAh actual capacity and 98.4% capacity retention, corresponding to a low capacity decay of 0.58% per day (Fig. 4a). Compared with 0.1 M [(NPr)₂V]Cl₄/FcNCl-based AORFB (78.19% capacity retention and capacity decay of 8.94% per day at 40 mA cm^− 2 After 350 cycles), the stability of the NDI/FcNCl-based AORFB has been improved by 15 times, resulting from the better conjugate structure of NDI than [(NPr)₂V]Cl₄. The polarization performance of the NDI/FcNCl-based AORFB was verified, which revealed a peak power density output at 62 mW cm^− 2 at an approximately 100% state of charge (Fig. 4b). The battery rate performance under different current densities was tested (Fig. 4c-e). The Coulombic efficiency (CE) of the battery is nearly 100% at different current densities from 20 mA cm^− 2 to 70 mA cm^− 2 Furthermore, the battery shows reasonable energy efficiencies (EE, 52%) and voltage efficiencies (VE, 52%) at 40 mA cm^− 2, which decrease linearly with increasing operational current density, which is due to the increased polarization and internal resistance (Figures S17a). Moreover, the CV plots after the cycle further prove that there is no cross-contamination of the electrolytes resulting from the large molecular size (Figure S18a). At higher concentrations, 0.5 M NDI/FcNCl-based AORFB showed similar battery behaviors with a specific capacity of 22.08 Ah L^− 1 (Figure S13).

To investigate the battery performance with a more rigid and conjugate PDI as the electrolyte material, 0.02 M PDI/FcNCl-based AORFB was assembled with 0.02 M PDI as an anolyte and 0.02 M FcNCl as the catholyte (theoretical capacity of 8.576 mAh) (Fig. 5a). Since its solubility is only 0.08 M in 2 M NaCl, 0.02 M is used as an appropriate concentration for battery performance testing. At a current density of 20 mA cm^− 2, the battery maintains a capacity retention of 98.1% over 1500 cycles, corresponding to a capacity decay of 0.14% per day, with a maximum capacity of 7.66 mAh and a power density of 96 mW cm^− 2. In addition, at a lower concentration (0.01 M), the cell shows amazing stability, with no significant decay observed over 10000 cycles (which spanned 35 days) (Figure S16). This ultrastable flow battery system has brought down to the industrial application of AORFBs. To further improve the water solubility of PDI, we obtained TPDI by adding 6 hydrophilic groups, and the solubility was increased to 0.14 M. The 0.05 M TPDI/FcNCl-based AORFB was successfully prepared using 0.05 M TPDI as the anolyte and 0.05 M FcNCl as the catholyte (Fig. 5b). Similar to the 0.02 M PDI/FcNCl-based AORFB, the 0.05 M TPDI/FcNCl-based AORFB exhibits high capacity and long life properties at 20 mA cm^− 2. The battery delivers a capacity retention rate of 95.5% over 1600 cycles, corresponding to a capacity decay of 0.39% per day, with a maximum capacity of 18.63 mAh and a power density of 51 mW cm^− 2. The rate performance and polarization data are detailed in Figures S14 and S15 for the 0.02 M PDI/FcNCl-based and the 0.05 M TPDI/FcNCl-based AORFB. Similarly, the internal resistance of these batteries increases after cycling and there are no crosses between electrolytes (Figures S17 and S18). It is very obvious from Fig. 5b that the charge–discharge curve has one charging platform and two discharge platforms for 0.05 M TPDI/FcNCl-based AORFB (2-GCD), which is consistent with the CV curves. The second discharge platform has a lower voltage, and the starting voltage is close to 0.3 V, and the terminal curve is flat, implying lower voltage efficiency and incomplete discharge. To further release the charge, the 0.05 M TPDI/FcNCl-based AORFB is charged galvanostatically at 20 mA cm^− 2 between 0.1 and 1.5 V, discharged galvanostatically at 20 mA cm^− 2 and potentiostatically with a cutoff current density of 5 mA cm^− 2 (Fig. 5c). The battery shows a long life of 2300 cycles, with 80% capacity retention. Thus, cycling with potentiostatic cycling provides a more accurate method of electrolyte stability in an operating battery compared to galvanostatic cycling. Considering that the first discharge platform is higher, we conduct a galvanostatic stability test for one-electron storage, with a voltage range of 0.4–1.1 V (Fig. 5c). Compared with two-electron storage, one-electron storage has higher stability and voltage efficiency. There is no significant fade during 3500 cycles, and voltage efficiency up to 72% (56% for two-electron storage). Regardless of one-electron or two-electron storage, the battery performance of the TPDI-based AORFB is outstanding among the currently reported AORFBs. Such high capacity retention is also at the top-level from previous observations of viologen- and diimide-based compounds with two-electron storage, and the results fully prove that diimide derivatives are excellent anolytes suitable for energy storage (Fig. 5d and Table S2).

Electrolyte Recovery Experiment

One important criterion for the realization of industrialized production of new electrolyte materials is low cost. The arylene diimide derivatives are a very common class of raw materials for pharmaceutical intermediates and dyes, and this inexpensive property lays a foundation for the development of diimide-based AORFBs. And more, the diimide electrolytes are easier to synthesize, with a higher yield (ca. 90%) than the viologen (ca. 70%). From a full-cycle perspective, the cost of diimide-based AORFBs will be further reduced due to their longer lifetimes. To further reduce the construction cost of diimide-based AORFBs, an electrolyte recycling experiment was carried out. The NDI electrolyte with better solubility and less polarity is separated and purified by alumina column chromatography with methanol as the eluent, and its recycling efficiency is 60% after 350 cycles. The effectiveness of the recycled electrolyte is confirmed by stability tests (Figure S19). The PDI/TPDI electrolytes are difficult to recycle due to their lower solubility and greater polarity. The simple and efficient recycling strategies provide the impetus for the development of imide electrolytes, which proves that diimide derivatives are a kind of highly efficient anolyte material for AORFBs.

In summary, a series of inexpensive, highly water-soluble arylene diimide derivatives (NDI, PDI, and TPDI) were successfully synthesized and demonstrated excellent electrochemical properties. The introduction of hydrophilic ammonium cation groups into the main structure of naphthalene/perylene diimide greatly improved the water solubility. The large planar rigid structure of π-conjugation endowed them with the stable highly reduced species, which was consistent with the calculation results of aromaticity. The NICS(1) values changed from − 18.44 to 14.31 for NDI, from − 30.75 to -38.28 for PDI, and from − 29.98 to -38.74 for TPDI. A larger molecular size can effectively block the penetration of electrolytes. These were major factors for the two-electron storage stability of diimide anolytes. The 0.1 M NDI/FcNCl-based AORFB delivered 98.4% capacity retention at 40 mA cm^− 2 during 350 cycles using classical FcNCl as the catholyte, and its daily decay (0.58%) was only 1/15 of the [(NPr)₂V]Cl₄/FcNCl-based AORFB (8.94%). PDI/FcNCl-based and TPDI/FcNCl-based AORFBs also showed remarkable stability (1000–10000 cycles). This work not only expands the application of arylene diimide derivatives in neutral AORFBs but also brings spring to the industrial production of neutral AORFBs with the characteristics of low cost and long lifetimes.

Materials. All reactions were performed using standard Schlenk and glovebox (Vigor) techniques under argon atmosphere. All chemicals were purchased from Energy Chemical Inc, stored in an Argon glovebox. Toluene were distilled from sodium/benzophenone prior to use, and other chemicals were used as commercially available without further purification. Deionized water was purged overnight using Ar before use.

Synthesis of NDI. The cationic Naphthalene diimide derivative NDI was synthesized following the literature procedure.⁶³ 1,4,5,8-naphthalene tetracarboxylic dianhydride (NTDA) (1 g, 3.73 mmol) was dissolved in 120 mL dry toluene under N₂ atmosphere and heated to 90°C, and N, N-dimethyl-1,3-propanediamine (3 mL, 23.84 mmol) was added dropwise over 10 min. The reaction mixture was heated at 120°C for 24 h. The crude mixture was concentrated on a rotary evaporator, and the yellow crystalline NDI-1 was purified by recrystallizing from ethanol. Yield: 1 g (61%). A mixture of NDI-1 (1 g, 2.29 mmol), methyl chloride (5ml, 90.61 mmol), and 50 ml dry DMF were added. The solution was sealed in a pressure vial with a Teflon bushing and heated at 85°C for 12 h. The resulting suspension was cooled, collected by vacuum filtration, washed with DMF, acetone, and ether, and then dried in a vacuum to give NDI at 60°C overnight. A gray solid. Yield: 1.1 g (89%). ¹H NMR (400 MHz, D₂O) δ 8.59 (d, J = 2.4 Hz, 4H), 4.23 (t, J = 6.9 Hz, 4H), 3.57–3.48 (m, 4H), 3.14 (s, 18H), 2.32–2.22 (m, 4H). ¹³C NMR (101 MHz, D₂O) δ 164.09, 131.02, 126.01, 64.03, 52.91, 37.65, 21.39. HRMS (ESI) m/z: [M − 2Cl]²⁺ calcd for C₂₆H₃₄N₄O₄ 233.1285; found 233.12779.

Synthesis of PDI. The cationic perylene diimide derivative PDI was synthesized following the literature procedure.⁶⁵ 3,4,9,10-Perylenetetracarboxylic dianhydride (PTCDA) (2 g, 5.10 mmol) and N, N-dimethyl-1,3-propanediamine (6 mL, 47.68 mmol) were dissolved in 80 mL dry isobutanol and heated at 90°C for 24 h with stirring under N₂ atmosphere. The crude product was filtered, washed with deionized water and ethanol. The obtained residue was treated with 5% aqueous NaOH solution at 90°C for 30 min to remove the unreacted raw material The suspended mixture was filtered, washed with water and ethanol, and dried under vacuum to give the product as red solid PDI-1. Yield: 2.6 g (90%). To a mixture of PDI-1 (2 g, 3.57 mmol), methyl chloride (8 ml, 144.98 mmol), and 150 ml dry toluene were added. The solution was sealed in a pressure vial with a Teflon bushing and heated at 105°C for 12 h. The resulting suspension was cooled, collected by vacuum filtration, washed with toluene, and ether, and then dried in a vacuum to give PDI at 60°C overnight. A brown-red. Yield: 2.2 g (93%). ¹H NMR (400 MHz, CF₃COOD) δ 8.94 (s, 8H), 4.62 (s, 4H), 3.81 (s, 4H), 3.37 (s, 18H), 2.61 (s, 4H). ¹³C NMR (101 MHz, CF₃COOD). δ 165.93 (s), 136.37 (s), 133.24 (s), 129.41 (s), 126.44 (s), 124.48 (s), 121.85 (s), 64.88 (s), 53.22 (s), 37.92 (s), 21.84 (s). HRMS (ESI) [M − 2Cl]²⁺ calcd for C₃₆H₃₈N₄O₄ 295.1441; found 295.14421.

Synthesis of TPDI. Compound TPDI was synthesized according to the literature.⁶² 3,4,9,10-Perylenetetracarboxylic dianhydride (PTCDA) (1.62 g, 4.13 mmol) and N, N-dimethyl-1,3-propanediamine (30 mL, 201 mmol) were added and heated at 100°C for 28 hours, and then the temperature was gradually increased to 170°C over 4 hours. The mixture was then cooled to room temperature, and a mixture of ethanol and diethyl ether (1:3) was added. The resulting precipitate was collected by suction filtration, washed with diethyl ether, and dried under vacuum. A red solid TPDI-1. Yield: 2.4 g (90%). To a mixture of TPDI-1 (1.38 g, 2.13 mmol), water (6 ml), 85% formic acid (6.4 mL), and 30% formaldehyde (4.4 mL) were added. The solution was stirred at room temperature for 1 h and then heated at 120°C for 16 hours. Caution: at that time, the mixture would produce a lot of carbon dioxide, so it should be deflated slowly after the reaction. The solution was cooled to room temperature and then precipitated with ethyl ether, further to be centrifuged. The residue was dried under a vacuum. A red solid TPDI-2. Yield: 1.9 g (86%). A mixture of TPDI-2 (1.5 g, 1.45 mmol), dry MeOH (60 mL), and Na₂CO₃ (1 g) was stirred at room temperature for 12 h and then added methyl iodide (3 mL, 48.19 mmol), heated at 60°C for 12 h. The mixture was then cooled to room temperature and then precipitated with ethyl ether. The resulting precipitate was collected by suction filtration, washed with diethyl ether, and dried under vacuum. The product was exchanged for chloride by column anion exchange with Amberlite® IRA-900 chloride from anion exchange resin to give TPDI. A red solid. Yield: 1.39 g (90%). ¹H NMR (400 MHz, CF₃COOD) δ 8.95 (dd, J = 8.1 Hz, 8H), 5.10 (s, 4H), 4.56 (s, 20H), 4.35 (s, 8H), 3.60 (s, 36H). ¹³C NMR (101 MHz, CF₃COOD). δ 167.80 (s), 136.82 (s), 133.39 (s), 129.63 (s), 126.73 (s), 124.66 (s), 121.57 (s), 54.43 (s), 53.64 (s), 52.02 (s), 49.62 (s), 44.23 (s), 35.56 (s). HRMS (ESI) [M − 3Cl]²⁺ calcd for C50H74N8O4 283.5272; found 283.52952.

Synthesis of 1,1`-bis[3-(trimethylammonio)-propyl]-4,4`-bipyridinium tetrachloride - [(NPr) ₂ V]Cl ₄. Compound [(NPr)₂V]Cl₄ was synthesized according to the literature²⁰. In a 250 mL N₂ purged Schlenk flask, 4,4`-bipyridine (2.0 g, 12.8 mmol) was combined with (3-bromopropyl)trimethylammonium bromide (10 g, 38.3 mmol) in 15 mL of DMSO and stirred at 100°C for 3 h. The resulting precipitate was collected by suction filtration, washed with cold DMSO and acetonitrile. The product was exchanged for chloride by column anion exchange with Amberlite® IRA-900 chloride form anion exchange resin to give [(NPr)₂V]Cl₄. A white solid. Yield: 4.48 g (70%). ¹H NMR (400 MHz, D₂O) δ 9.09 (s, 2H), 8.51 (s, 2H), 4.74 (s, 2H), 3.47 (d, J = 4.4 Hz, 2H), 3.08 (d, J = 2.3 Hz, 9H), 2.57 (s, 2H).

Synthesis of (Ferrocenylmethyl)trimethylammonium Chloride – FcNCl.

FcNCl was synthesized according to a reported method.⁶⁶ (Ferrocenylmethyl)dimethylamine (10 g, 41.2 mmol), methyl chloride (49.4 mL, 445.3 mmol), and 25 mL dry CH₃CN were added to a round-bottom flask, which was stirred at RT overnight. The product was collected by filtration, washed with 10mL ether for 3 times, and dried under vacuum. A yellow solid. Yield: 10.9 g (90%). ¹H NMR (400 MHz, D₂O) δ 4.49 (t, J = 1.8 Hz, 2H), 4.40 (t, J = 1.8 Hz, 2H), 4.37 (s, 2H), 4.25 (s, 5H), 2.92 (s, 9H).

Materials Characterization. NMR spectra spectrum were collected using a Bruker 400 MHz NMR spectrometer. UV-Vis measurements were performed using a DH-2000-BAL Scan spectrophotometer. The cyclic voltammetry (CV) in solution were measured using CHI660E B157216. The Linear sweep voltammetry (LSV) was measured on a rotating disk electrode (RDE) device (Pine Instruments Co., USA, 0.1963 cm²). Electrochemical Impedance analysis (EIS) was performed using an Autolab electrochemical workstation (AUT86797-302N, Metrohm instruments, Switzerland). High-resolution mass spectra (HRMS) were collected on a Bruker maxis UHR-TOF mass spectrometer in an ESI positive mode. EPR was measured using a Bruker A300-9.5/12 instrument at room temperature in dry degassed methanol. The EPR parameters for the experiments are as follows: modulation frequency = 100 kHz, modulation amplitude = 1.0 G, time constant = 81.92 msec, conversion time = 80.00 msec, center field = 3514.503 G, sweep width = 1000 G, microwave attenuation = 26.3 dB, microwave power = 0.00471 mW. All battery tests were conducted under an Ar atmosphere. The flow battery was tested at RT on a battery tester (NEWARE instrument, CT-4008T-5V12A-S1-F). All photographs were taken using a Nikon D5100 digital camera.

Solubility tests. The solubility of imide derivatives was tested in 2 M NaCl solutions by UV-Vis spectrum.⁶⁷ Firstly, adding imide derivatives into 2 M NaCl solutions until no further solid could be dissolved. A saturated solution of imide derivatives was obtained after centrifugation. Then take a small amount of the saturated solution and diluted it with a known magnification. The concentration was measured by the UV-Vis spectrum. Finally, the concentration was calculated according to a pre-calibrated absorbance-concentration curve of known concentrations of imide derivatives.

The cyclic voltammogram (CV) studies. All electrochemical CV experiments were carried out in 0.5 M NaCl electrolyte solutions. Redox potential was referenced to NHE. The glassy carbon electrode (d = 3 mm) was used for the working electrode, which was polished using Al₂O₃ suspended in deionized H₂O, then rinsed with deionized H₂O, and dried with airflow. The platinum sheet (1 cm²) was used for the counter electrode. The reference electrode consisted of a silver wire coated with a layer of AgCl and suspended in a solution of 3 M KCl electrolyte (Ag/AgCl, vs. NHE).

The electrochemical kinetics studies. All linear sweep voltammetry (LSV) studies were conducted using a CHI660E and a Pine in a three-electrode configuration. A glassy carbon rotating electrode (5 mm diameter) was used as the working electrode along with a platinum sheet counter electrode and an Ag/AgCl reference electrode same as used in LSV studies. Before data collection, the electrolyte was purged by Ar for 20 minutes to remove the oxygen dissolved in the electrolyte. LSV scans were recorded at a scan rate of 5 mV s^− 1.

The diffusion coefficient (D, cm² s^− 1) was determined by the slope of the fitted Levich equation (Eq. 1).

$${i}_{l}=0.620nFAc{D}^{2/3}{v}^{-1/6}{\omega }^{1/2} \left(1\right)$$

where ${i}_{l}$ was the mass transfer limiting current from RDE tests, n was the electron transfer number, Faraday’s constant F = 96485 C mol^− 1, electrode area A = 0.1963 cm², concentration c = 1×10^− 6 mol cm^− 3, kinetic viscosity v = 9×10^− 3 cm² s^− 1 (0.5 M NaCl aqueous solution), ω represented rotate speed (rad/s).

The electron transfer constant (${k}_{0}$, cm s^− 1) was calculated from the Koutecký-Levich equation (Eq. 2).

$${i}^{-1}={{i}_{l}}^{-1}+{{i}_{k}}^{-1}={\left(0.620nFAc{D}^{2/3}{v}^{-1/6}{\omega }^{1/2}\right)}^{-1}+{\left(nFA{k}_{0}c\right)}^{-1} \left(2\right)$$

where $i$ represented the measured current, ${i}_{k}$ was the kinetic current (no mass transfer), which can be obtained from the butler-volmer equation (Eq. 3).

$${\eta }=\frac{2.303RT}{\alpha nF}\text{l}\text{o}\text{g}{i}_{0}-\frac{2.303RT}{\alpha nF}\text{l}\text{o}\text{g}i \left(3\right)$$

where ${\eta }$ represented over potential, ${i}_{0}$ was the exchange current, $\alpha$ was the transfer coefficient, R is the universal gas constant (8.314 J K^− 1mol^− 1), and T is the temperature (298 K). When η was equal to 0, ${i}_{0}$ can be obtained and ${k}_{0}$ can be calculated by the following equation (Eq. 4).

$${k}_{0}=\frac{{i}_{0}}{FAc} \left(4\right)$$

Theoretical Calculations. To simulate the experimental UV-Vis in water, the Polarizable Continuum Model (PCM) as a self-consistent reaction field (SCRF) was used for the calculation of equilibrium geometries, vibrational frequencies, and excited state calculations. The geometries for the ground state of these compounds were optimized at the B3LYP hybrid functional and 6-311 + G(d) basis set for all atoms.³⁵ The calculated maximum absorption wavelength (λTD-DFT), oscillator strength (f), molecular orbitals (MOs) involved in the main transitions were reported in this work. It should be pointed out that the structures of all stationary points were fully optimized, and frequency calculations were performed at the same level. The frequency calculations confirmed the nature of all revealed equilibrium geometries: there were no imaginary frequencies. The simulated UV–Vis spectra for optimized molecules were performed at the time-dependent density functional theory (TD-DFT/B3LYP) at the ground-state equilibrium geometries in water solution, in association with the 6-311 + G(d) basis set. All of the above computational calculations reported in this work were performed using the Gaussian 09 code.^21,68 The volume was estimated using Marching Tetrahedron (MT) mothed, based on the vdW surface defined by ρ = 0.001 au isosurface, using the Multiwfn code.⁶⁹ NMR chemical shifts for Nucleus-independent chemical shift (NICS)^70,71 values were calculated at the points shown using the GIAO⁷² method.

Permeability measurements. The membrane permeability of active materials was measured with a homemade H-tube, assembling with two L-shaped glass tubes, two glass stoppers, one metal clip, and two gaskets separated by a piece of AMV membrane. The flange and gasket diameter is 17 mm. 20 mL solution of 0.02 M NDI (PDI, or TPDI) in 2 M NaCl was placed on one storage tank as the donating side, while the other storage tank filled with 20 mL 2 M NaCl was used as the receiving side. The whole device was placed on the agitator, and the magneton was added for stirring at all times. The crossover of active materials was periodically monitored by measuring the concentration of the solution in the receiving side by UV-Vis (test every two days).

The permeability of active materials was calculated using Fick’s law (Eq. 5).

$\text{p}= \frac{\text{ln}\left(1-\frac{2{C}_{t}}{{C}_{0}}\right)\left(-\frac{{V}_{0}l}{2A}\right)}{t}$ $\left(5\right)$

Where P is the permeability (cm² s^− 1), C_t is the concentration measured at the receiving side at time t, C₀ (0.02 M) is the initial concentration of active materials at the donating side. V₀ (20 mL) is the initial volume on either the receiving or donating sides. A (2.19 cm²) is the effective membrane area. l (50 µm) is the thickness of the AMV membrane. t is the time (s).

In-suit UV-Vis spectra. The UV-Vis, computer, Neware instrument, and flow battery were connected in the glove box. Anolyte was stored in a customized cuvette (1 cm*1 cm*10 cm) and catholyte was stored in a sample bottle. The concentration of arylene diimide derivatives and FcNCl used are 10^− 5 M and 2*10^− 5 M for in-situ UV-Vis spectrum and their solution volume are 8mL and 20 mL, respectively. The flow rate is 30 ml min^− 1. The current density is 0.5 mA cm^− 2. The data is recorded quickly during charging and discharging.

Full cell tests. A home-made full battery was assembled with two steel plates, two polytetrafluoroethylene insulation plates, two Cu plate collectors, two graphite plates, and two graphite-felts, which are separated by AMV membrane. For NDI/FcNCl-based and TPDI/FcNCl-based AORFB, the active area is 9 cm². For PDI/FcNCl-based AORFB, the active area is 4 cm². The electrolyte materials with the same concentration are dissolved in 2 M NaCl. For one-electron storage, the anolyte and catholyte are 8 mL and 10 mL respectively. For two-electron storage, the anolyte and catholyte are 8 mL and 20 mL respectively. The electrolytes are pumped into the cell at a flow rate of 60 mL min^− 1 through a peristaltic pump (BT100M, Baoding Chuang Rui Precision Pump Co., Ltd.). The reservoirs are purged with Ar to displace any O₂ in the system and then sealed.

Electrochemical Impedance Spectroscopy (EIS). The Potentio-controlled Electrochemical impedance spectroscopy (EIS) of batteries were obtained by Nava with a frequency range from 0.01 Hz to 10 kHz.

Data availability

The authors declare that all the data supporting the findings of this study are available within the paper and its Supplementary Information files or from the corresponding author upon request.

Acknowledgements

This work was supported by the Natural Science Foundation of China (22175138, 21875180), the Key Research and Development Program of Shaanxi (2021GXLH-Z023), the Independent Innovation Capability Improvement Project of Xi’an Jiaotong University (PY3A066), the Fundamental Research Funds for the Central Universities (xhj032021008-03). We thank Lu Bai at the Instrument Analysis Center of Xi’an Jiaotong University for their assistance with the HRMS measurements. We also thank Lijing Ma at the State Key Laboratory of Multiphase Flow in Power Engineering of Xi'an Jiaotong University for her assistance with EPR measurements.

Author Contributions

Gang He and Xu Liu conceived the idea for the study. Xu Liu and Chaoyu Bao prepared the samples and conducted characterizations. Xu Liu and Xuri Zhang conducted electrochemical measurements. Xu Liu and Zengrong Wang completed the full battery tests. Xu Liu and Guoping Li contributed to the DFT calculations. Xu Liu and Gang He wrote the manuscript. Xu Liu, Guoping Li, Ni Yan, Ming-Jia Li, and Gang He revised and polished the manuscript.

Competing interests

The authors declare no competing interests.

Park, M., Ryu, J., Wang, W. & Cho, J. Material Design and Engineering of Next-Generation Flow-Battery Technologies. Nat. Rev. Mater. 2, 16080, (2017).
Ziegler, M. S. et al. Storage Requirements and Costs of Shaping Renewable Energy Toward Grid Decarbonization. Joule 3, 2134–2153, (2019).
Wu, Z. et al. Highly Conductive Two-Dimensional Metal-Organic Frameworks for Resilient Lithium Storage with Superb Rate Capability. ACS Nano 14, 12016–12026, (2020).
Li, X. et al. Symmetry-Breaking Design of an Organic Iron Complex Catholyte for A Long Cyclability Aqueous Organic Redox Flow Battery. Nat. Energy 6, 873–881, (2021).
Yuan, Z. et al. Low-Cost Hydrocarbon Membrane Enables Commercial-Scale Flow Batteries for Long-Duration Energy Storage. Joule 6, 884–905, (2022).
Back, J. et al. Tunable Redox-Active Triazenyl-Carbene Platforms: A New Class of Anolytes for Non-Aqueous Organic Redox Flow Batteries. ACS Appl. Mater. Interfaces 12, 37338–37345, (2020).
Ma, T. et al. Porphyrin-Based Symmetric Redox-Flow Batteries towards Cold-Climate Energy Storage. Angew. Chem. Int. Ed. 57, 3158–3162, (2018).
Yao, Y., Lei, J., Shi, Y., Ai, F. & Lu, Y.-C. Assessment methods and performance metrics for redox flow batteries. Nat. Energy 6, 582–588, (2021).
Kwabi, D. G., Ji, Y. & Aziz, M. J. Electrolyte Lifetime in Aqueous Organic Redox Flow Batteries: A Critical Review. Chem. Rev. 120, 6467–6489, (2020).
Brushett, F. R., Aziz, M. J. & Rodby, K. E. On Lifetime and Cost of Redox-Active Organics for Aqueous Flow Batteries. ACS Energy Lett. 5, 879–884, (2020).
Service, R. F. Advances in Flow Batteries Promise Cheap Backup Power. Science 362, 508–509, (2018).
Luo, J. et al. Unprecedented Capacity and Stability of Ammonium Ferrocyanide Catholyte in pH Neutral Aqueous Redox Flow Batteries. Joule 3, 149–163, (2019).
Li, Z. & Lu, Y. C. Material Design of Aqueous Redox Flow Batteries: Fundamental Challenges and Mitigation Strategies. Adv. Mater. 32, 2002132, (2020).
Ding, Y., Zhang, C., Zhang, L., Zhou, Y. & Yu, G. Molecular Engineering of Organic Electroactive Materials for Redox Flow Batteries. Chem. Soc. Rev. 47, 69–103, (2018).
Winsberg, J., Hagemann, T., Janoschka, T., Hager, M. D. & Schubert, U. S. Redox-Flow Batteries: From Metals to Organic Redox-Active Materials. Angew. Chem. Int. Ed. 56, 686–711, (2017).
Nambafu, G. S. et al. Pyromellitic Diimide Based Bipolar Molecule for Total Organic Symmetric Redox Flow Battery. Nano Energy 94, 106963, (2022).
Zhang, C. et al. Highly Concentrated Phthalimide-Based Anolytes for Organic Redox Flow Batteries with Enhanced Reversibility. Chem 4, 2814–2825, (2018).
Hu, B., Luo, J., Hu, M., Yuan, B. & Liu, T. L. A pH-Neutral, Metal-Free Aqueous Organic Redox Flow Battery Employing an Ammonium Anthraquinone Anolyte. Angew. Chem. Int. Ed. 58, 16629–16636, (2019).
Kwabi, D. G. et al. Alkaline Quinone Flow Battery with Long Lifetime at pH 12. Joule 2, 1894–1906, (2018).
DeBruler, C. et al. Designer Two-Electron Storage Viologen Anolyte Materials for Neutral Aqueous Organic Redox Flow Batteries. Chem 3, 961–978, (2017).
Liu, Y. et al. Screening Viologen Derivatives for Neutral Aqueous Organic Redox Flow Batteries. ChemSusChem 13, 2245–2249, (2020).
Striepe, L. & Baumgartner, T. Viologens and Their Application as Functional Materials. Chem. Eur. J. 23, 16924–16940, (2017).
Janoschka, T., Martin, N., Hager, M. D. & Schubert, U. S. An Aqueous Redox-Flow Battery with High Capacity and Power: The TEMPTMA/MV System. Angew. Chem. Int. Ed. 55, 14427–14430, (2016).
Liu, Y. et al. A Long-Lifetime All-Organic Aqueous Flow Battery Utilizing TMAP-TEMPO Radical. Chem 5, 1861–1870, (2019).
Winsberg, J. et al. TEMPO/Phenazine Combi-Molecule: A Redox-Active Material for Symmetric Aqueous Redox-Flow Batteries. ACS Energy Lett. 1, 976–980, (2016).
Pan, M. et al. Reversible Redox Chemistry in Pyrrolidinium-Based TEMPO Radical and Extended Viologen for High-Voltage and Long-Life Aqueous Redox Flow Batteries. Adv. Energy Mater. 2103478, (2022).
Hu, B., Hu, M., Luo, J. & Liu, T. L. A Stable, Low Permeable TEMPO Catholyte for Aqueous Total Organic Redox Flow Batteries. Adv. Energy Mater. 12, 2102577, (2021).
Cong, G., Cong, G., Zhou, Y., Li, Z. & Lu, Y.-C. A Highly Concentrated Catholyte Enabled by a Low-Melting-Point Ferrocene Derivative. ACS Energy Lett. 2, 869–875, (2017).
Luo, J., Hu, M., Wu, W., Yuan, B. & Liu, T. L. Mechanistic Insights of Cycling Stability of Ferrocene Catholytes in Aqueous Redox Flow Batteries. Energy Environ. Sci. 15, 1315–1324, (2022).
Chen, Q. et al. Designer Ferrocene Catholyte for Aqueous Organic Flow Batteries. ChemSusChem 14, 1295–1301, (2021).
Park, M. et al. A High Voltage Aqueous Zinc–Organic Hybrid Flow Battery. Adv. Energy Mater. 9, 1900694, (2019).
Robertson, L. A. et al. Fluorescence-Enabled Self-Reporting for Redox Flow Batteries. ACS Energy Lett. 5, 3062–3068, (2020).
Orita, A., Verde, M. G., Sakai, M. & Meng, Y. S. A Biomimetic Redox Flow Battery Based on Flavin Mononucleotide. Nat. Commun. 7, 13230, (2016).
Li, G. et al. Electrochromic Poly(chalcogenoviologen)s as Anode Materials for High-Performance Organic Radical Lithium-Ion Batteries. Angew. Chem. Int. Ed. 58, 8468–8473, (2019).
Li, G. et al. Narrow-Bandgap Chalcogenoviologens for Electrochromism and Visible-Light-Driven Hydrogen Evolution. Angew. Chem. Int. Ed. 57, 4897–4901, (2018).
Zhang, J. et al. How to Manipulate Through-Space Conjugation and Clusteroluminescence of Simple AIEgens with Isolated Phenyl Rings. J. Am. Chem. Soc. 143, 9565–9574, (2021).
Chen, Q. et al. Organic Electrolytes for pH-Neutral Aqueous Organic Redox Flow Batteries. Adv. Funct. Mater. 32, 2108777, (2021).
Sun, Y., Zou, Q. & Lu, Y. C. Fast and Reversible Four-Electron Storage Enabled by Ethyl Viologen for Rechargeable Magnesium Batteries. Adv. Energy Mater. 9, 1903002, (2019).
Bridges, C. R., Stolar, M. & Baumgartner, T. Phosphaviologen-Based Pyrene‐Carbon Nanotube Composites for Stable Battery Electrodes. Batteries Supercaps 3, 268–274, (2019).
Beh, E. S. et al. A Neutral pH Aqueous Organic–Organometallic Redox Flow Battery with Extremely High Capacity Retention. ACS Energy Lett. 2, 639–644, (2017).
Huang, J. et al. Radical Stabilization of a Tripyridinium-Triazine Molecule Enables Reversible Storage of Multiple Electrons. Angew. Chem. Int. Ed. 60, 2–7, (2021).
Luo, J., Hu, B., Debruler, C. & Liu, T. L. A π-Conjugation Extended Viologen as a Two-Electron Storage Anolyte for Total Organic Aqueous Redox Flow Batteries. Angew. Chem. Int. Ed. 57, 231–235, (2018).
Hu, S. et al. Phenylene-Bridged Bispyridinium with High Capacity and Stability for Aqueous Flow Batteries. Adv. Mater. 33, 2005839, (2021).
Liu, X. et al. Thienoviologen Anolytes for Aqueous Organic Redox Flow Batteries with Simultaneously Enhanced Capacity Utilization and Capacity Retention. J. Mater. Chem. A 10, 9830–9836, (2022).
Zu, Y. et al. Carbonyl Bridge-Based p-π Conjugated Polymers as High-Performance Electrodes of Organic Lithium-Ion Batteries. ACS Appl. Mater. Interfaces 12, 18457–18464, (2020).
Sun, M., Mullen, K. & Yin, M. Water-Soluble Perylenediimides: Design Concepts and Biological Applications. Chem. Soc. Rev. 45, 1513–1528, (2016).
Zheng, S. et al. Orthoquinone-Based Covalent Organic Frameworks with Ordered Channel Structures for Ultrahigh Performance Aqueous Zinc-Organic Batteries. Angew. Chem. Int. Ed. 61, e202117511, (2022).
Yao, C. J. et al. Two-Dimensional (2D) Covalent Organic Framework as Efficient Cathode for Binder-free Lithium-Ion Battery. ChemSusChem 13, 2457–2463, (2020).
Iron, M. A., Cohen, R. & Rybtchinski, B. On the Unexpected Stability of the Dianion of Perylene Diimide in Water—A Computational Study. J. Phys. Chem. A 115, 2047–2056, (2011).
Schon, T. B., Tilley, A. J., Kynaston, E. L. & Seferos, D. S. Three-Dimensional Arylene Diimide Frameworks for Highly Stable Lithium Ion Batteries. ACS Appl. Mater. Interfaces 9, 15631–15637, (2017).
Zhang, B. et al. Isometric Thionated Naphthalene Diimides as Organic Cathodes for High Capacity Lithium Batteries. Chem. Mater. 32, 10575–10583, (2020).
Xie, J., Gu, P. & Zhang, Q. Nanostructured Conjugated Polymers: Toward High-Performance Organic Electrodes for Rechargeable Batteries. ACS Energy Letters 2, 1985–1996, (2017).
Xie, J., Wang, Z., Xu, Z. J. & Zhang, Q. Toward a High-Performance All-Plastic Full Battery with a'Single Organic Polymer as Both Cathode and Anode. Adv. Energy Mater. 8, 1703509, (2018).
Russell, J. C. et al. High-Performance Organic Pseudocapacitors via Molecular Contortion. Nat. Mater. 20, 1136–1141, (2021).
Biedermann, F., Elmalem, E., Ghosh, I., Nau, W. M. & Scherman, O. A. Strongly Fluorescent, Switchable Perylene Bis(diimide) Host-Guest Complexes with Cucurbit[8]uril in Water. Angew. Chem. Int. Ed. 51, 7739–7743, (2012).
Wang, H. et al. In Situ Hypoxia-Induced Supramolecular Perylene Diimide Radical Anions in Tumors for Photothermal Therapy with Improved Specificity. J. Am. Chem. Soc. 144, 2360–2367, (2022).
Wiberg, C., Owusu, F., Wang, E. & Ahlberg, E. Electrochemical Evaluation of a Napthalene Diimide Derivative for Potential Application in Aqueous Organic Redox Flow Batteries. Energy Technol. 7, 1900843, (2019).
Milton, M. et al. Molecular Materials for Nonaqueous Flow Batteries with a High Coulombic Efficiency and Stable Cycling. Nano Lett. 17, 7859–7863, (2017).
Cao, J., Tian, J., Xu, J. & Wang, Y. Organic Flow Batteries: Recent Progress and Perspectives. Energy Fuels 34, 13384–13411, (2020).
Yan, W. et al. All-Polymer Particulate Slurry Batteries. Nat. Commun. 10, 2513, (2019).
Medabalmi, V., Sundararajan, M., Singh, V., Baik, M.-H. & Byon, H. R. Naphthalene Diimide as a Two-Electron Anolyte for Aqueous And Neutral pH Redox Flow Batteries. J. Mater. Chem. A 8, 112218, (2020).
Xu, Z. et al. Molecular Size, Shape, and Electric Charges: Essential for Perylene Bisimide-based DNA Intercalator to localize in Cell Nuclei and Inhibit Cancer Cell Growth. ACS Appl. Mater. Interfaces 7, 9784–9791, (2015).
Song, Q., Li, F., Wang, Z. & Zhang, X. Correction: A Supramolecular Strategy for Tuning the Energy Level of Naphthalenediimide: Promoted Formation of Radical Anions with Extraordinary Stability. Chem. Sci. 6, 5088–5089, (2015).
Pan, M. et al. The Dual Role of Bridging Phenylene in an Extended Bipyridine System for High-Voltage and Stable Two-Electron Storage in Redox Flow Batteries. ACS Appl. Mater. Interfaces 13, 44174–44183, (2021).
Deng, H., Chai, Y., Yuan, R. & Yuan, Y. In Situ Formation of Multifunctional DNA Nanospheres for a Sensitive and Accurate Dual-Mode Biosensor for Photoelectrochemical and Electrochemical Assay. Anal. Chem. 92, 8364–8370, (2020).
Hu, B., DeBruler, C., Rhodes, Z. & Liu, T. L. Long-Cycling Aqueous Organic Redox Flow Battery (AORFB) toward Sustainable and Safe Energy Storage. J. Am. Chem. Soc. 139, 1207–1214, (2017).
Li, H. et al. A Stable Organic Dye Catholyte for Long-life Aqueous Flow Battery. Chem. Commun. 56, 13824–13827, (2020).
Gaussian 09 Rev. D.01 (Gaussian, Inc.: Wallingford, CT, 2013).
Lu, T. & Chen, F. Multiwfn: a multifunctional wavefunction analyzer. J. Comput. Chem. 33, 580–592, (2012).
Schleyer, P. v. R., Jiao, H., Hommes, N. J. R. v. E., Malkin, V. G. & Malkina, O. L. An Evaluation of the Aromaticity of Inorganic Rings: Refined Evidence from Magnetic Properties. J. Am. Chem. Soc. 119, 12669–12670, (1997).
Schleyer, P. V. R., Maerker, C., Dransfeld, A., Jiao, H. & van Eikema Hommes, N. J. R. Nucleus-Independent Chemical Shifts: A Simple and Efficient Aromaticity Probe. J. Am. Chem. Soc. 118, 6317–6318, (1996).
Hfiser, M., Ahlrichs, R., Baron, H. P., Weis, P. & Horn, H. Direct Computation of Second-Order SCF Properties of Large Molecules on Workstation Computers with an Application to Large Carbon Clusters. Anal. Chim. Acta 83, 455–470, (1992).

There is NO Competing Interest.

SupportingInformation.pdf
Supporting Information

PDF

Version 1

posted 01 Jul, 2022

You are reading this latest preprint version

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

Status:

Version 1

Abstract

Figures

Introduction

Results And Discussion

Synthesis and Structure Characterization

Electrochemical Characterization

Electrochemical Kinetic Characterization

Density Functional Theory Calculations

In situ UV Spectra

Full Battery Tests

Electrolyte Recovery Experiment

Discussion

Methods

Declarations

References

Competing Interests

Supplementary Files

Status:

Version 1