EAGER: RUI: Elucidation of the AlCl4- and Al2Cl7- ions speciation, interactions and transport in electrolytes comprised of RTILs by Multi-Nuclear NMR techniques.

非技术综述：社会能源需求要求扩大现有电能存储系统的能力。锂离子电池主导了市场，部分原因是锂的高重量和体积容量，并推动了电动汽车和智能手机等产品的发展。然而，由于锂的长期用途有限，它们价格昂贵，更适合便携式和小规模应用。此外，锂离子电池可能存在火灾危险，这一问题已导致其应用和运输受到限制。为了确保社会的进步，需要改进电能存储系统，开发铝离子电池就是一种途径。铝具有低成本、低易燃性和高电荷存储容量等优点，因而具有很大的吸引力。铝离子电池比锂离子电池更便宜、更安全，它们可以用于风能和太阳能等可再生能源所需的大规模存储应用。然而，它们的广泛应用受到许多因素的阻碍，包括缺乏强化的电解液。该项目由NSF材料研究部的固态和材料化学计划资助，确定了铝离子电池的电解液，并研究了离子传输的基本特性，使其能够在未来获得更好的性能。该项目纳入了面向所有层次和兴趣的学生的教育方案，并让所有教育水平的学生参与研究活动。该项目对科学的更广泛影响是通过加强能量储存系统来促进科学进步。这反过来又通过改善我们的生活和环境条件来促进社会福利。技术摘要：该项目由美国国家科学基金会材料研究部的固态和材料化学计划资助，阐明了基本的离子-离子相互作用及其对铝离子电池电解液中离子动力学和传输的影响，解决了对铝离子的溶剂化、它们的相互作用和传输缺乏基本了解的问题。这三方面的知识对于优化电解液和促进铝离子电池作为替代储能设备的发展是必要的。因此，Pi和她的团队通过测量多核(质子、氟、铝和氯)磁共振自扩散系数和自旋晶格弛豫时间来研究所有离子的可用自由体积，这两者都是随着静水压力和温度的增加而变化的。特别关注的将是铝核。该方法既包括在边缘磁场中确定压力相关的自扩散系数，也包括在均匀磁场中确定聚焦参数的温度相关性。通过这些测量，研究人员了解了非质子有机溶剂对铝离子动力学的影响，并首次成功地应用了铝高压核磁共振技术。感兴趣的电解液是含有咪唑和吡咯烷阳离子、氟磺酰胺和氯离子的室温离子液体，含有氯化铝化合物和有机非质子添加剂，如环戊烷和苯，AlCl3/RTIL的摩尔比在酸性范围内。这项研究为直接确定其他非锂离子在电解液中的质量传输打开了大门，并传播了极未得到充分利用的边缘场高压核磁共振技术的能力。这一奖项反映了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。

Non-technical summary:Societal energy needs demand the expansion of current electrical energy storage systems capabilities. Lithium ion batteries have dominated the markets due in part to lithium's high gravimetric and volumetric capacities and have advanced the development of products like electric vehicles and smartphones. However, they are expensive and more suitable for portable and small-scale applications due to lithium's limited long-term utility. Additionally, lithium ion batteries can be a fire hazard, a problem which has caused restrictions in their application and transportation. To ensure the advancement of society, improvements in electrical energy storage systems are needed and the development of aluminum ion batteries is one approach. Aluminum metal is attractive because of its low cost, low flammability and high charge storage capacity. Aluminum ion batteries are cheaper and safer than lithium ion ones, and they can be used for large-scale storage applications as needed by renewables like wind and solar. Their wide-scale application is, however, impeded by a number of factors, including a lack of enhanced electrolytes. This project, funded by the Solid State and Materials Chemistry Program in NSF's Division of Materials Research, identifies electrolytes for aluminum ion batteries and investigates fundamental characteristics of ion transport that enable better performance in the future. The project incorporates educational programs for students of all levels and interests and involves students of all education levels in the research activities. The scientific broader impact of this project is to promote the advancement of science through enhancement of energy storage systems. This in turn advances the welfare of society through improvements in our living and environmental conditions. Technical summary: This project, funded by the Solid State and Materials Chemistry Program in NSF's Division of Materials Research, elucidates the fundamental ion-ion interactions and their effects on ion dynamics and transport in aluminum ion battery electrolytes, addressing a lack of fundamental understanding of the aluminum ions' solvation, their interactions and transport. Knowledge of all three is necessary for the optimization of the electrolytes and for advancing the development of aluminum ion batteries as alternative energy storage devices. Therefore, the PI and her group investigate the available free volume of all ions through measurements of multi-nuclear (protons, fluorine, aluminum and chlorine) magnetic resonance self-diffusion coefficients and spin-lattice relaxation times, both as a function of increasing hydrostatic pressure, and temperature. Special focus will be on the aluminum nucleus. The procedure involves working both in the fringe-magnetic field to determine the pressure dependent self-diffusion coefficients, and in the homogeneous field to determine the temperature dependencies of the focused parameters. Through these measurements the researchers gain knowledge of the effect of aprotic organic solvents on the aluminum ion dynamics, and produce the first successful application of the aluminum high-pressure nuclear magnetic resonance technique. The electrolytes of interest are room temperature ionic liquids with imidazolium and pyrrolidinium cations, fluorosulfonamide and chlorine anions, containing the aluminum chloride compound combined with organic aprotic additives such as cyclopentane and benzene, with molar ratios of AlCl3/RTIL in the acidic range. This research opens the door for direct determination of the mass transport of other non-lithium ions in electrolytes and broadcasts the capabilities of the much-underutilized fringe-field high-pressure nuclear magnetic resonance technique.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.