scholarly journals Thermodynamics, Charge Transfer and Practical Considerations of Solid Boosters in Redox Flow Batteries

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2111
Author(s):  
Mahdi Moghaddam ◽  
Silver Sepp ◽  
Cedrik Wiberg ◽  
Antonio Bertei ◽  
Alexis Rucci ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Energy Storage ◽  
Storage Capacity ◽  
Point Of View ◽  
Charge Storage ◽  
Energy Storage Density ◽  
Redox Potentials ◽  
Redox Flow Batteries ◽  
Redox Electrolyte ◽  
Flow Batteries

Solid boosters are an emerging concept for improving the performance and especially the energy storage density of the redox flow batteries, but thermodynamical and practical considerations of these systems are missing, scarce or scattered in the literature. In this paper we will formulate how these systems work from the point of view of thermodynamics. We describe possible pathways for charge transfer, estimate the overpotentials required for these reactions in realistic conditions, and illustrate the range of energy storage densities achievable considering different redox electrolyte concentrations, solid volume fractions and solid charge storage densities. Approximately 80% of charge storage capacity of the solid can be accessed if redox electrolyte and redox solid have matching redox potentials. 100 times higher active areas are required from the solid boosters in the tank to reach overpotentials of <10 mV.

scholarly journals Tuning the Performance of Aqueous Organic Redox Flow Batteries from First Principles

2020 ◽  
Author(s):  
Junting Yu ◽  
Tianshou Zhao ◽  
Ding Pan
Keyword(s):  
Energy Storage ◽  
First Principles ◽  
High Performance ◽  
Large Scale ◽  
Electrical Energy ◽  
Ab Initio Molecular Dynamics ◽  
Redox Potentials ◽  
Redox Flow Batteries ◽  
Flow Batteries ◽  
Entropy Effects

<div>Aqueous organic redox flow batteries have many appealing properties in the application of large-scale energy storage. The large chemical tunability of organic electrolytes shows great potential to improve the performance of flow batteries. Computational studies at the quantum-mechanics level are very useful to guide experiments, but in previous studies explicit water interactions and thermodynamic effects were ignored. Here, we applied the computational electrochemistry method based on ab initio molecular dynamics to calculate redox potentials of quinones and their derivatives. The calculated results are in excellent agreement with experimental data. We mixed side chains to tune their reduction potentials, and found that solvation interactions and entropy effects play a significant role in side-chain engineering. Based on our calculations, we proposed several high-performance negative and positive electrolytes. Our first-principles study paves the way towards the development of large-scale and sustainable electrical energy storage.</div>

A stable two-electron-donating phenothiazine for application in nonaqueous redox flow batteries

2017 ◽  
Vol 5 (46) ◽  
pp. 24371-24379 ◽  
Author(s):  
Jeffrey A. Kowalski ◽  
Matthew D. Casselman ◽  
Aman Preet Kaur ◽  
Jarrod D. Milshtein ◽  
Corrine F. Elliott ◽  
...  
Keyword(s):  
Storage Capacity ◽  
Charge Storage ◽  
Simple Modification ◽  
Redox Flow Batteries ◽  
Molecular Charge ◽  
Flow Batteries

Simple modification of N-ethylphenothiazine (left) with electron-donating substituents (right) increases the molecular charge-storage capacity of this donor.

scholarly journals A Quantitative Evaluation of Computational Methods to Accelerate the Study of Alloxazine-Derived Electroactive Compounds for Energy Storage

2020 ◽  
Author(s):  
Qi Zhang ◽  
Abhishek Khetan ◽  
Süleyman Er
Keyword(s):  
Energy Storage ◽  
Computational Methods ◽  
High Throughput ◽  
Density Functional ◽  
Computational Cost ◽  
Orbital Energy ◽  
Redox Potentials ◽  
Redox Flow Batteries ◽  
Computational Screening ◽  
Flow Batteries

Alloxazines are a promising class of organic electroactive molecules for application in aqueous redox flow batteries. Preliminary studies show that structural modifications of alloxazines with electron-donating and/or -withdrawing functional groups help in tuning of their redox properties. High-throughput computational screening enables rational and time-efficient discovery of functional compounds. The effectiveness of high-throughput computational screening efforts is strongly dependent on the accuracy and speed at which the performance descriptors are estimated for a large pool of candidate compounds. Here, we performed a quantitative study to assess the performance of computational methods, including the forcefield based molecular mechanics, semi-empirical quantum mechanics, density functional based tight binding, and density functional theory, on the basis of their accuracy and computational cost in predicting the redox potentials of electroactive alloxazines. We compared the performances of various energy-based descriptors, including the redox reaction energy and the frontier orbital energies of the reactant and product molecules. We found that the lowest unoccupied molecular orbital energy of the reactant molecules is the best performing descriptor for the alloxazines, which is in contrast to other classes of molecules, such as quinones that we reported earlier. Importantly, we present a flexible<i> in silico</i> approach to accelerate both the singly and the high-throughput computational screening studies, therewithal considering the level of accuracy <i>vs</i> measured electrochemical data, that is principally applicable for the discovery of efficient, alloxazine-derived organic compounds for energy storage in aqueous redox flow batteries.

scholarly journals Tuning the Performance of Aqueous Organic Redox Flow Batteries from First Principles

2020 ◽  
Author(s):  
Junting Yu ◽  
Tianshou Zhao ◽  
Ding Pan
Keyword(s):  
Energy Storage ◽  
First Principles ◽  
High Performance ◽  
Large Scale ◽  
Electrical Energy ◽  
Ab Initio Molecular Dynamics ◽  
Redox Potentials ◽  
Redox Flow Batteries ◽  
Flow Batteries ◽  
Entropy Effects

<div>Aqueous organic redox flow batteries have many appealing properties in the application of large-scale energy storage. The large chemical tunability of organic electrolytes shows great potential to improve the performance of flow batteries. Computational studies at the quantum-mechanics level are very useful to guide experiments, but in previous studies explicit water interactions and thermodynamic effects were ignored. Here, we applied the computational electrochemistry method based on ab initio molecular dynamics to calculate redox potentials of quinones and their derivatives. The calculated results are in excellent agreement with experimental data. We mixed side chains to tune their reduction potentials, and found that solvation interactions and entropy effects play a significant role in side-chain engineering. Based on our calculations, we proposed several high-performance negative and positive electrolytes. Our first-principles study paves the way towards the development of large-scale and sustainable electrical energy storage.</div>

scholarly journals Tuning the Performance of Aqueous Organic Redox Flow Batteries from First Principles

2020 ◽  
Author(s):  
Junting Yu ◽  
Tianshou Zhao ◽  
Ding Pan
Keyword(s):  
Energy Storage ◽  
First Principles ◽  
High Performance ◽  
Large Scale ◽  
Electrical Energy ◽  
Ab Initio Molecular Dynamics ◽  
Redox Potentials ◽  
Redox Flow Batteries ◽  
Flow Batteries ◽  
Entropy Effects

<div>Aqueous organic redox flow batteries have many appealing properties in the application of large-scale energy storage. The large chemical tunability of organic electrolytes shows great potential to improve the performance of flow batteries. Computational studies at the quantum-mechanics level are very useful to guide experiments, but in previous studies explicit water interactions and thermodynamic effects were ignored. Here, we applied the computational electrochemistry method based on ab initio molecular dynamics to calculate redox potentials of quinones and their derivatives. The calculated results are in excellent agreement with experimental data. We mixed side chains to tune their reduction potentials, and found that solvation interactions and entropy effects play a significant role in side-chain engineering. Based on our calculations, we proposed several high-performance negative and positive electrolytes. Our first-principles study paves the way towards the development of large-scale and sustainable electrical energy storage.</div>

scholarly journals A Quantitative Evaluation of Computational Methods to Accelerate the Study of Alloxazine-Derived Electroactive Compounds for Energy Storage

2020 ◽  
Author(s):  
Qi Zhang ◽  
Abhishek Khetan ◽  
Süleyman Er
Keyword(s):  
Energy Storage ◽  
Computational Methods ◽  
High Throughput ◽  
Density Functional ◽  
Computational Cost ◽  
Orbital Energy ◽  
Redox Potentials ◽  
Redox Flow Batteries ◽  
Computational Screening ◽  
Flow Batteries

Alloxazines are a promising class of organic electroactive molecules for application in aqueous redox flow batteries. Preliminary studies show that structural modifications of alloxazines with electron-donating and/or -withdrawing functional groups help in tuning of their redox properties. High-throughput computational screening enables rational and time-efficient discovery of functional compounds. The effectiveness of high-throughput computational screening efforts is strongly dependent on the accuracy and speed at which the performance descriptors are estimated for a large pool of candidate compounds. Here, we performed a quantitative study to assess the performance of computational methods, including the forcefield based molecular mechanics, semi-empirical quantum mechanics, density functional based tight binding, and density functional theory, on the basis of their accuracy and computational cost in predicting the redox potentials of electroactive alloxazines. We compared the performances of various energy-based descriptors, including the redox reaction energy and the frontier orbital energies of the reactant and product molecules. We found that the lowest unoccupied molecular orbital energy of the reactant molecules is the best performing descriptor for the alloxazines, which is in contrast to other classes of molecules, such as quinones that we reported earlier. Importantly, we present a flexible<i> in silico</i> approach to accelerate both the singly and the high-throughput computational screening studies, therewithal considering the level of accuracy <i>vs</i> measured electrochemical data, that is principally applicable for the discovery of efficient, alloxazine-derived organic compounds for energy storage in aqueous redox flow batteries.

A Self-Trapping, Bipolar Viologen Bromide Electrolyte for Aqueous Redox Flow Batteries

2020 ◽  
Author(s):  
wenda wu ◽  
Jian Luo ◽  
Fang Wang ◽  
Bing Yuan ◽  
Tianbiao Liu
Keyword(s):  
Redox Flow Battery ◽  
Capacity Retention ◽  
Redox Flow Batteries ◽  
Redox Electrolyte ◽  
Charge Process ◽  
Self Trapping ◽  
Flow Batteries ◽  
Total Capacity ◽  
Neutral Conditions ◽  
Low Solubility

Aqueous organic redox flow batteries (AORFBs) have become increasing attractive for scalable energy storage. However, it remains challenging to develop high voltage, powerful AORFBs because of the lack of catholytes with high redox potential. Herein, we report methyl viologen dibromide (<b>[MV]Br<sub>2</sub></b>) as a facile self-trapping, bipolar redox electrolyte material for pH neutral redox flow battery applications. The formation of the <b>[MV](Br<sub>3</sub>)<sub>2</sub></b> complex was computationally predicted and experimentally confirmed. The low solubility <b>[MV](Br<sub>3</sub>)<sub>2</sub></b> complex in the catholyte during the battery charge process not only mitigates the crossover of charged tribromide species (Br<sub>3</sub><sup>-</sup>) and addresses the toxicity concern of volatile bromine simultaneously. A 1.53 V bipolar MV/Br AORFB delivered outstanding battery performance at pH neutral conditions, specifically, 100% total capacity retention, 133 mW/cm<sup>2</sup> power density, and 60% energy efficiency at 40 mA/cm<sup>2</sup>.

Progress in redox flow batteries, remaining challenges and their applications in energy storage

RSC Advances ◽  
2012 ◽  
Vol 2 (27) ◽  
pp. 10125 ◽  
Author(s):  
Puiki Leung ◽  
Xiaohong Li ◽  
Carlos Ponce de León ◽  
Leonard Berlouis ◽  
C. T. John Low ◽  
...  
Keyword(s):  
Energy Storage ◽  
Redox Flow Batteries ◽  
Flow Batteries

Integration of Adapted Thin-film Photovoltaics into Solar Vanadium Redox Flow Batteries for Energy Storage

2018 ◽  
Author(s):  
Sebastián Murcia-López ◽  
Nina Carretero ◽  
Cristina Flox ◽  
Félix Urbain ◽  
Joan R. Morante ◽  
...  
Keyword(s):  
Thin Film ◽  
Energy Storage ◽  
Redox Flow Batteries ◽  
Flow Batteries ◽  
Thin Film Photovoltaics ◽  
Vanadium Redox
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