Kinetics and stability of redox-active organics for electrochemical systems

电化学系统中氧化还原活性有机物的动力学和稳定性

• 批准号: 1914543
• 负责人: Michael Aziz
• 金额: $ 53万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1914543&HistoricalAwards=false
• 关键词: Kinetics; stability; redox; active; organics

Redox flow batteries (RFBs) are large-scale energy storage systems that enable the use of intermittent renewable energy resources, such as solar and wind power, which may not always be available when energy is being consumed. Unlike other battery technologies, RFBs can store significant amounts of energy in fluids stored in large reservoirs that are then flowed through cells to insert (i.e. charge) or to extract energy (i.e. discharge) from the system. Aqueous flow batteries employing dissolved organic redox active compounds (materials that can pick up and give off electrons) might safely and inexpensively store and deliver large amounts of electrical energy. These materials are environmentally benign, inflammable, and can be designed for low-cost production through modern, large-scale chemical synthesis technologies. However, chemical stability currently limits their long-term use in energy storage installations. This research project addresses fundamental understanding of the charge-discharge energy properties and degradation pathways of these energy-storing materials. The fundamental knowledge gained will also contribute towards other redox-based chemical processes, CO2 capture technologies and other electron-transfer processes relevant to biology. The project also continues a relationship with Boston's Museum of Science on a partnership to provide interactive presentations and content on the theme of renewable energy and its use in our nation's economy.This fundamental research project will explore the thermodynamic stability and electrochemical kinetics of small organic molecules such as quinones in aqueous electrolytes. The use application is to understand chemical and electrochemical degradation at a mechanistic level. In aqueous solutions, some quinones are known to undergo rapid and reversible two-electron reductions to hydroquinone; they form the basis for new RFB electrolytes with the potential for enhanced efficiency and reduced cost. However, even the best of these material systems experiences a slow loss of capacity that, in some cases, has been attributed to molecular degradation. The investigators have identified a number of degradation pathways including the formation of semiquinone radical intermediates from single-electron reduction and correlated these to permanent loss of cell performance. Furthermore, the PIs have observed dramatic changes in quinone electrochemical kinetics when dissolved in solutions of various pH electrolytes. This project is a cross-school collaboration between the Department of Chemistry and Chemical Biology and the School of Engineering and Applied Sciences. This research will investigate the influences of molecular structure, substituent groups, pH, oxidation state, and electrolyte salts on molecular thermodynamic stability and electrochemical kinetics for redox-active organic compounds. The team will synthesize new molecules designed to answer fundamental questions and will evaluate their thermodynamic and kinetic properties using specially designed electrochemical flow cells.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

氧化还原液流电池（RFB）是一种大规模的能量存储系统，能够使用间歇性的可再生能源，如太阳能和风能，这些能源在能源消耗时可能并不总是可用的。与其他电池技术不同，RFB可以将大量能量储存在大型储存器中的流体中，然后流过电池以插入（即充电）或从系统中提取能量（即放电）。采用溶解的有机氧化还原活性化合物（可以拾取和释放电子的材料）的水液流电池可以安全且廉价地存储和输送大量电能。这些材料对环境友好，易燃，可以通过现代化的大规模化学合成技术进行低成本生产。然而，化学稳定性目前限制了它们在储能装置中的长期使用。该研究项目解决了对这些储能材料的充放电能量特性和降解途径的基本理解。所获得的基本知识也将有助于其他基于氧化还原的化学过程、二氧化碳捕获技术和其他与生物学有关的电子转移过程。该项目还继续与波士顿科学博物馆的合作伙伴关系，提供互动演示和内容的主题可再生能源及其在我们国家的经济使用。这个基础研究项目将探讨小有机分子的热力学稳定性和电化学动力学，如醌在水电解质。使用应用程序是在机械水平上理解化学和电化学降解。 在水溶液中，已知一些醌类化合物会发生快速且可逆的双电子还原反应，生成对苯二酚;它们构成了新型RFB电解质的基础，具有提高效率和降低成本的潜力。然而，即使是这些材料系统中最好的也会经历缓慢的容量损失，在某些情况下，这归因于分子降解。研究人员已经确定了许多降解途径，包括单电子还原形成半醌自由基中间体，并将其与电池性能的永久丧失相关联。此外，PI已经观察到醌电化学动力学在溶解于各种pH电解质的溶液中时的显著变化。该项目是化学和化学生物学系与工程和应用科学学院之间的跨学校合作。本研究将探讨分子结构、取代基、pH值、氧化态及电解质盐对氧化还原活性有机化合物的分子热力学稳定性及电化学动力学的影响。该团队将合成旨在回答基本问题的新分子，并将使用专门设计的电化学流动电池评估其热力学和动力学性质。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Extremely Stable Anthraquinone Negolytes Synthesized from Common Precursors

• DOI: 10.1016/j.chempr.2020.03.021
• 发表时间: 2020-06-11
• 期刊: CHEM
• 影响因子: 23.5
• 作者: Wu, Min;Jing, Yan;Aziz, Michael J.
• 通讯作者: Aziz, Michael J.

The Poor Academic’s DC-Offset for Reversing Polarity in Electrochemical Cells: Application to Redox Flow Cells

可怜的学术界用于反转电化学电池极性的直流偏移：在氧化还原流通池中的应用

• DOI: 10.1149/1945-7111/ac91a8
• 发表时间: 2022
• 期刊: Journal of The Electrochemical Society
• 影响因子: 3.9
• 作者: Amini, Kiana;Fell, Eric M.;Aziz, Michael J.
• 通讯作者: Aziz, Michael J.

In situ electrochemical recomposition of decomposed redox-active species in aqueous organic flow batteries

• DOI: 10.1038/s41557-022-00967-4
• 发表时间: 2022-06-16
• 期刊: NATURE CHEMISTRY
• 影响因子: 21.8
• 作者: Jing, Yan;Zhao, Evan Wenbo;Aziz, Michael J.
• 通讯作者: Aziz, Michael J.

Highly Stable, Low Redox Potential Quinone for Aqueous Flow Batteries**

用于水液电池的高度稳定、低氧化还原电位醌**

• DOI: 10.1002/batt.202200009
• 发表时间: 2022
• 期刊: Batteries & Supercaps
• 影响因子: 5.7
• 作者: Wu, Min;Bahari, Meisam;Jing, Yan;Amini, Kiana;Fell, Eric M.;George, Thomas Y.;Gordon, Roy G.;Aziz, Michael J.
• 通讯作者: Aziz, Michael J.

A High Potential, Low Capacity Fade Rate Iron Complex Posolyte for Aqueous Organic Flow Batteries

• DOI: 10.1002/aenm.202202444
• 发表时间: 2022-10
• 期刊: Advanced Energy Materials
• 影响因子: 27.8
• 作者: Jinxu Gao;Kiana Amini;T. George;Y. Jing;Tatsuhiro Tsukamoto;Dawei Xi;R. Gordon;M. Aziz