RII Track-4: Deciphering the Role of Polarization on Ion Transport in Ionic Liquid Batteries

RII Track-4：解读极化对离子液体电池中离子传输的作用

• 批准号: 1929163
• 负责人: Jindal Shah
• 金额: $ 27.49万
• 依托单位: Oklahoma State 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: 2019-12-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929163&HistoricalAwards=false
• 关键词: RII; Track; Deciphering; Role; Polarization

Safe and reliable operation of Li-ion batteries depends critically on the type of electrolytes used. Ionic liquids, novel solvents composed entirely of ions much like common salt but existing as liquids at the temperatures of battery operation, present exciting opportunities as electrolytes due to low volatility and nonflammability. Potentially a million ionic liquids and roughly a billion ionic liquid-ionic liquid mixtures can be designed providing a materials platform for developing next generation of Li-ion batteries. Despite these significant advantages, the progress in ionic liquid-based Li-ion batteries has been limited due to slow Li-ion transport, which increases the time for charging. The objective of the current project is, therefore, to understand ionic liquid-Li interactions to enable the design of novel ionic liquids for fast Li-ion transport. By partnering with researchers from the Pacific Northwest National Laboratory (PNNL), the PI will develop the capability to study ionic liquid-Li interactions using state-of-the-art modeling techniques and DOE's Leadership Computing Facilities. The expertise developed will be shared with undergraduate and graduate students at Oklahoma State University and researchers in the jurisdiction. It is expected that the collaboration resulting from this fellowship will foster engagement of researchers at OSU with those at PNNL and lead to development of new ideas accelerating discoveries in multiple science and engineering disciplines.Li-ion batteries present a promising technological solution for sustainable transportation. One of the major components of Li-ion batteries is the electrolyte through which an efficient transport of Li ions is critical for reliable operation. Room temperature ionic liquids easily fulfill the required electrolyte properties such as electrochemical stability, nonvolatility, nonflammability, and high conductivity over a wide range of temperatures. Despite significant advantages, application of ionic liquids as electrolytes is hampered because the high viscosity of many ionic liquids hinders transport of Li ions causing slow charging and discharging times. Mixing two ionic liquids offers a simple yet powerful strategy to overcome this challenge. However, currently there is a lack of fundamental understanding regarding which ionic liquid combinations are likely to yield promising electrolytes. Further, accurate modeling of such mixtures necessitates capturing the composition-dependent changes in electronic distributions around ions, highlighting the need for polarization. First principles molecular dynamics (FPMD) based on density functional theory approach naturally incorporates this crucial aspect in modeling ionic liquids. The PI will develop this capability in his research group by partnering with researchers from the Pacific Northwest National Laboratory. FPMD simulations will be performed on DOE's Leadership Computing Facilities for ionic liquid mixtures, Li+-ionic liquid mixtures, ionic liquids at electrode interfaces and in the presence of electric field. The newly developed expertise will be shared with researchers at the host institution increasing its research capacity. The proposed fellowship will lead to the training of a graduate student and integration of FPMD simulations in the PI's 'Molecular Modeling and Simulation' course.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.

锂离子电池的安全可靠操作取决于使用的电解质的类型。离子液体是完全由离子组成的新型溶剂，就像常见的盐一样，但在电池操作的温度下作为液体存在，由于低波动性和不易受性而带来了令人兴奋的机遇，作为电解质。可以设计一百万个离子液体，大约有十亿个离子液态液体混合物，为开发下一代锂离子电池提供材料平台。尽管有这些显着的优势，但由于锂离子运输的缓慢，离子液体基电池的进展受到限制，这增加了充电时间。因此，当前项目的目的是了解离子液体-LI相互作用，以使新型离子液体进行快速锂离子运输的设计。通过与太平洋西北国家实验室（PNNL）的研究人员合作，PI将开发使用最先进的建模技术和DOE的领导力计算设施来研究离子Liquid-LI相互作用的能力。开发的专业知识将与俄克拉荷马州立大学的本科生和研究生共享，以及管辖范围的研究人员。预计该奖学金所产生的合作将促进OSU的研究人员与PNNL的研究人员的参与，并导致发展新想法，加速了多个科学和工程学科中的发现。Li-ION电池提出了一种有希望的可持续运输技术解决方案。锂离子电池的主要组成部分之一是电解质，通过该电解质对可靠的操作至关重要。室温离子液体可以轻松地履行所需的电解质特性，例如电化学稳定性，不易旋转性，不易受性和高电导率，并在广泛的温度下进行高电导率。尽管有显着的优势，但将离子液体作为电解质的应用受到阻碍，因为许多离子液体的高粘度阻碍了液离子的运输，从而导致缓慢充电和放电时间。混合两种离子液体提供了一个简单而强大的策略来克服这一挑战。但是，目前缺乏基本的了解，即哪些离子液体组合可能会产生有希望的电解质。此外，这种混合物的准确建模需要捕获离子周围电子分布的组成依赖性变化，从而突出了极化的需求。基于密度功能理论方法的第一原理分子动力学（FPMD）自然融合了建模离子液体的关键方面。 PI将通过与太平洋西北国家实验室的研究人员合作，在其研究小组中发展这一能力。 FPMD模拟将在DOE的领导力计算设施上进行离子液体混合物，LI+离子液体混合物，电极接口处的离子液体以及电场的存在。新开发的专业知识将与东道机构的研究人员共享，以提高其研究能力。 拟议的奖学金将导致对研究生的培训，并在PI的“分子建模和模拟”课程中整合FPMD模拟。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准来评估的。