EAGER: Collaborative Research: Shear Dependent Reaction Kinetics in Particulate Electrochemical Energy Storage

锂离子电池被认为是便携式电子产品、新兴绿色技术和电动汽车的卓越存储设备。然而，用于提高电极材料的电子和离子导电性的添加剂约占电池体积的三分之一，破坏了电池的能量和功率密度，并损害了系统的循环寿命。另一方面，氧化还原液流电池在放大灵活性方面表现出了很大的优势，但其能量密度受到金属离子氧化还原电偶在液体溶剂中的溶解度的限制。最近，人们提出了一种新的概念，将离子储存的半固态电活性物质流入和流出电池组件，以创建高能量和功率密度的氧化还原液流电池。要实现这一新概念的巨大潜力，需要从根本上了解移动的电极颗粒和流动的电解液对离子/电荷传输的影响，以及与静态电池配置相比的充放电动力学。这个合作项目汇集了专注于电化学储能系统的Steingart博士和专注于复杂流体物理的Sun博士，整合了流变学、反应化学、材料加工和电池性能方面的专业知识，以实现半固态液流电池的概念。这个迫切的项目的目标是通过集成的建模和实验建立一种基线方法来表征和预测大质量分数流动浆料电极的电化学-机械耦合行为。智能价值在半固态液流电池配置中，正负极浆料通常是非牛顿的，其稳定性极具挑战性。利用光学透明流动池和速率剪切粘度计，直接测定了界面填充和流动对电导率和反应速率的影响。通过将电导率实验与整体反应实验并行运行，PI可以使电导率解耦。通过我们的粒子传输机制解析、电化学耦合模型提供的见解，PI将能够了解半固态电极流动系统中流动、粘度、离子导电性、电导率、颗粒尺寸、颗粒尺寸分布和电极动力学的耦合行为。广泛影响更具成本效益、更持久、更高能量/功率密度的电池解决方案的开发是迈向国家电气化的关键一步-S个人交通工具和更稳定高效的电网。半固态液流电池实现了高能量密度存储，同时消除了对反应材料寿命的担忧。该项目在普林斯顿和德雷克塞尔的化学和机械工程师之间建立了一种新的令人兴奋的合作，以实现高效、可靠的液流电池。研究生和本科生都将从拟议项目的跨学科性质中受益。

Lithium-ion batteries are considered the pre-eminent storage device for portable electronics, emerging green technologies, and electric vehicles. However, additives that are used to boost electronic and ionic conductivities of the electrode materials comprise about 1/3 of the battery volume, undermining both energy and power density of the cell, as well as impairing the cycle life of the system. Redox flow batteries on the other hand have shown great advantages on their scale-up flexibility, but their energy density is limited by the solubility of metal ion redox couples in liquid solvents. Recently, a new concept of flowing ion-storing semi-solid electroactive materials into and from a battery assembly to create a high energy and power density redox flow battery has been proposed. Realizing the tremendous potential of this new concept requires a fundamental understanding of the effects of moving electrode particles and flowing electrolytes on ion/charge transport as well as charging/discharging kinetics compared with those in static battery configurations. This collaborative project brings together Dr. Steingart specializing on electrochemical energy storage systems and Dr. Sun on complex fluids physics, integrating expertise on rheology, reaction chemistry, materials processing, and battery performance for the realization of semi- solid flow battery concept. The objective of this EAGER project is to create a baseline methodology for characterizing and predicting the electrochemical-mechanical coupling behavior of large mass fraction flowing slurry electrodes through integrated modeling and experiments.Intellectual MeritIn the semi-solid flow battery configuration, positive and/or negative electrode slurries are usually non- Newtonian and their stability is extremely challenging. Using an optically transparent flow cell and rate shear viscometry, the effect of interpacticle packing and flow on conductivity, and reaction rate are directly determined. By running conductivity experiments in parallel with overall reaction experiments, the PIs can decouple the electrical conductivity. Through the insights provided by our particle transport mechanism-resolved, electrochemistry-coupled model, PIs will be able to understand the coupled behavior of flow, viscosity, ionic conductivity, electrical conductivity, particle size, particle size distribution and electrode kinetics in semi-solid electrode flow systems.Broader ImpactsThe development of more cost-effective, long lasting, and high energy/power-density battery solution is a crucial step toward the electrification of the nation?s personal transportation and more stable and efficient electrical grids. Semi-solid flow batteries enable high energy density storage while removing lifetime concerns from the reacting material. This project builds a new exciting collaboration between chemical and mechanical engineers at Princeton and Drexel to enable efficient, reliable flow batteries. Both graduate and undergraduate students will benefit from the interdisciplinary nature of the proposed project.