CAREER: Design and Understanding up from the Atomic Scale of Multivalent Intercalation Electrodes for High-Energy-Density Rechargeable Batteries

迫切需要改进电动汽车的储能技术，并大规模整合可再生电网储能，以提高国内能源安全。目前，诸如锂离子电池的最先进的能量存储技术具有不足的能量密度，并且对于在这些应用中的广泛使用来说过于昂贵。基于多价离子的电池电极（例如，铝离子或锌离子）在电荷存储容量上产生超过单价的显著增强（例如，锂离子）电极。当与其相应的金属电极配对时，能量密度的潜在变革性增益是可能的。然而，到目前为止，多价电池性能是缺乏的，这在很大程度上是由于对电极在连续充电和放电循环时经历的复杂的电子、化学和结构变化的基本理解和控制有限。该项目的研究工作将调查多价电极使用过程中发生的基本电化学过程，从而深入了解如何设计和实现具有显著增强的储能性能的可充电电池。将研究可充电铝离子和锌离子电极，因为铝和锌金属都是地球上丰富的、低成本的、不易燃的、无毒的，并且表现出高体积电荷存储容量。该项目还包括通过“电池训练营”与当地高中的高中科学教师直接互动，在高中一级推进STEM教育的外联工作。外展将强调共同开发动手，适合高中生使用的年龄实验室实验，以帮助理解电化学工程概念。该项目还将在纽约（CUNY）内举办一个NMR学校，让研究生将这项技术和其他先进的光谱方法结合起来，以丰富他们各自的研究项目。该研究项目的科学和技术目标是：（i）从原子尺度上了解，多价阳离子在结晶过渡金属化合物中电化学嵌入的基础过程和性质，以及（ii）利用这种理解来发现和优化具有显著增强的体能量存储特性的新型嵌入电极。将研究铝离子（Al3+）和锌离子（Zn2+）嵌入电极，以利用铝和锌金属的有利电化学性质，同时能够研究不同离子价态和电荷密度的影响。模型过渡金属化合物的电子和晶体结构将系统地变化，使他们的关系，从分子到细胞水平的电化学嵌入现象的调查。随后，从模型研究中获得的知识将用于启动目标材料发现工作，其中新的电极组合物和结构将被合成并探索用于下一代铝离子和锌离子电池。新型的多维固态核磁共振（NMR）方法将产生新的见解原子水平的环境，结构和动力学的嵌入阳离子和电极框架，揭示离子嵌入和电荷转移机制。总的来说，这项工作预计将建立和验证分子设计原则，旨在实现多价嵌入电极与增强的电荷存储容量，嵌入电位，和率properties.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

There is a critical need for improved energy storage technologies for electric vehicles and large-scale integration of renewable electricity grid storage to improve domestic energy security. Currently, state-of-the-art energy storage technologies such as lithium-ion batteries have insufficient energy density and are too costly for broad use in these applications. Battery electrodes based on multivalent ions (e.g., aluminum ions or zinc ions) yield significant enhancements in electric charge storage capacity over monovalent (e.g., lithium-ion) electrodes. When paired with their corresponding metal electrodes, potentially transformative gains in energy density are possible. However, multivalent battery performance to date is lacking, in large part due to limited fundamental understanding and control of the complex electronic, chemical, and structural changes that the electrodes undergo upon continued charge and discharge cycles. Research efforts in this project will investigate the fundamental electrochemical processes that occur during the use of multivalent electrodes, yielding insights into how to design and realize rechargeable batteries with significantly enhanced energy storage properties. Rechargeable aluminum-ion and zinc-ion electrodes will be investigated as both aluminum and zinc metals are earth abundant, low-cost, non-flammable, non-toxic, and exhibit high volumetric charge storage capacity. The project also includes outreach efforts that will advance STEM education at the high school level by directly interacting with high school science teachers at a local high school via a "Battery Bootcamp". Outreach will stress the co-development of hands-on, age appropriate laboratory experiments for the high school students to use to help understand electrochemical engineering concepts. The project also will conduct a NMR School within the City University of New York (CUNY) for graduate students to incorporate this technique and other advanced spectroscopic methods to enrich their own respective research projects.The scientific and technological objectives of this research project are to (i) understand, up from the atomic scale, the processes and properties underpinning electrochemical intercalation of multivalent cations in crystalline transition metal compounds and (ii) to use this understanding to discover and optimize novel intercalation electrodes with significantly enhanced bulk energy storage properties. Aluminum-ion (Al3+) and zinc-ion (Zn2+) intercalation electrodes will be investigated to leverage the favorable electrochemical properties of aluminum and zinc metal while enabling the effects of differing ion valence and charge density to be studied. The electronic and crystalline structures of model transition metal compounds will be systematically varied, enabling investigations of their relationships to electrochemical intercalation phenomena from the molecular to the cell level. Subsequently, knowledge gained from model studies will be used to initiate targeted materials discovery efforts, wherein new electrode compositions and structures will be synthesized and explored for next-generation aluminum-ion and zinc-ion batteries. Novel multi-dimensional solid-state nuclear magnetic resonance (NMR) methods will yield new insights into the atomic-level environments, structures, and dynamics of intercalated cations and electrode frameworks, revealing ion intercalation and charge transfer mechanisms. Overall, this work is expected to establish and validate molecular design principles aimed at realizing multivalent intercalation electrodes with enhanced charge storage capacities, intercalation potentials, and rate properties.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.