Collaborative Research: Establishing Design Principles for Molecular Engineering of High Concentration Redox Electrolytes

该项目专注于一种名为非水氧化还原液流电池(RFB)的电池，该电池有望用于大规模、固定的储能应用。在电网规模的储能选择方面，RFB具有优势，当与电网相连时，这种储能方案将降低整体能源消耗。与其他RFB设计相比，含有有机电活性物种的非水RFB具有以下独特特征：更高的工作电压、无腐蚀性的电解液、更小的尺寸以及使用可扩展的有机活性材料(更环保，潜在成本更低)。该合作项目致力于基础研究，以支持为具有高能量密度、更好的稳定性和可接受的流体流动特性的非水RFB设计电解液。该项目不仅将建立为下一代电网蓄电池设计电解液所需的基础知识，还将为可持续能源经济所需的其他电化学技术提供基本见解。首席调查员布鲁希特和奥多姆与STEM领域中代表性不足的群体进行了广泛的合作，并在两个研究小组中指导本科生和研究生。此外，私人投资机构将与彼此的机构建立暑期学生交流计划。在麻省理工学院，Brushett博士将参与Think计划，该计划旨在培养从事有益于社区的项目的高中生的非凡创新、网络和知识。在英国肯塔基大学，奥多姆博士将专注于混合艺术与科学，该项目将通过无障碍活动吸引非科学家了解能源收集和储存方面的概念和问题，并将继续担任英国扩大你的视野年度会议的联合组织者。基础知识空白存在于(1)稳定的浓氧化还原活性溶液的分子设计和(2)这些浓电解液的电化学表征方面。目前，大多数研究集中在稀相条件下的分子发现和电化学表征，然后直接集成到未优化的实验室流动池中进行初步循环分析。这种方法导致了该领域的不均衡发展，因为到目前为止，大多数非水流动电池表现出较差的性能和耐用性。目前尚不清楚观察到的结果是由于氧化还原有机材料的基本不稳定，氧化还原电解液的物理和电化学性质随浓度变化，还是由于电池设计和工程中的失败。这一合作研究项目专注于开发基于取代吩噻嗪的可溶且稳定的氧化还原活性分子，作为平台化学，用于表征用于非水液流电池的含有高浓度氧化还原活性物质和有机电解液中的支持盐的溶液的物理和电化学性质。这项研究的主要科学成果将是从根本上了解化学结构和周围电解液对高浓度氧化还原活性有机材料在非质子有机电解液中的性能和耐用性的作用。此外，将开发新的电化学方法，使浓缩的非水氧化还原电解液具有明确的特征。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project focuses on a type of battery called non-aqueous redox flow batteries (RFBs) that are promising for large-scale, stationary energy storage applications. RFBs have advantages for electrical grid-scale energy storage options that would reduce overall energy consumption when linked with an electrical grid. Non-aqueous RFBs that contain organic electro-active species have the following unique features relative to other RFB designs: higher operating voltages, non-corrosive electrolytes, smaller size, and use of scalable organic active materials (which are more environmentally friendly and potentially lower cost). This collaborative project addresses fundamental research to support the design of electrolytes for non-aqueous RFBs with high energy density, better stability, and acceptable fluid flow properties. This project will not only establish the foundational knowledge necessary to design electrolytes for next-generation grid storage batteries but will also provide fundamental insights into other electrochemical technologies necessary for a sustainable energy economy. The Principal Investigators Brushett and Odom have worked extensively with underrepresented groups in STEM fields and with mentoring undergraduate and graduate students in both research groups. Further, the PIs will establish summer student exchange programs with each other's institutions. At MIT, Dr. Brushett will engage with the THINK program, which seeks to foster exceptional innovation, networking, and knowledge in high school students working on projects that benefit the community. At University of Kentucky (UK), Dr. Odom will focus on Mixing Art & Science, which will introduce non-scientists to concepts and issues in energy collection and storage by attracting them with an accessible activity and will continue to serve as a co-organizer for UK's Expanding Your Horizons Annual Conference. Fundamental knowledge gaps exist both in (1) the molecular design of stable concentrated redox active solutions and (2) the electrochemical characterization of these concentrated electrolytes. At present, most investigations have focused on molecular discovery and electrochemical characterization under dilute conditions followed by direct integration into an unoptimized laboratory flow cell for preliminary cycling analysis. This approach has led to uneven advances in the field as, to date, most nonaqueous flow cells have shown poor performance and durability. It is unclear whether the observed results are due to fundamental instabilities of the redox organic materials, concentration-dependent changes in the physical and electrochemical properties of redox electrolytes, or failures in cell design and engineering. This collaborative research project focuses on the development of soluble and stable redox active molecules, based on substituted phenothiazines, as a platform chemistry for characterizing physical and electrochemical properties of solutions containing high concentrations of redox active materials and supporting salts in organic electrolytes - referred to as "redox electrolytes" - for use in nonaqueous flow batteries. The major scientific outcome of this research will be fundamental understanding of the role of chemical structure and surrounding electrolytes on the performance and durability of redox active organic materials at high concentrations in aprotic organic electrolytes. Further, new electrochemical methods will be developed to enable unambiguous characterization of concentrated nonaqueous redox electrolytes.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.