Optimizing Ion Mobility, Chemical Stability, and Mechanical Rigidity in Composite Electrolytes

优化复合电解质中的离子淌度、化学稳定性和机械刚性

• 批准号: 1106058
• 负责人: John Kieffer
• 金额: $ 55.2万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1106058&HistoricalAwards=false
• 关键词: Optimizing; Ion; Mobility; Chemical; Stability

NON-TECHNICAL DESCRIPTION: Energy storage is a critical aspect of sustainable and renewable energy technologies, and mobile information systems. While the chemical nature of anode and cathode determines the amount of energy that can be stored in a battery of a given size, the separator material (or electrolyte) controls its charge cycling rates, lifetime, and structural integrity. High conductance of the ion responsible for the electrochemical conversion (e.g., lithium) facilitates high power release and short recharge times. Chemical compatibility between electrolyte and electrode materials prevents the formation of blocking layers that would suppress the electrochemical process. Mechanical rigidity of the electrolyte inhibits dendrite growth that can short circuit the device and lead to catastrophic failure (e.g., spontaneous combustion). Unfortunately, these performance criteria rely on conflicting materials properties, and the challenge lies in devising a composite structure that maximizes all these attributes. In this research, a combination of simulation-based predictive design, advanced materials synthesis approaches, microstructural characterization, and performance monitoring is employed to develop new composite electrolytes with unsurpassed performance. This project contributes to the development of human resources in an innovative way by training a doctoral student in combining experimental and computational tools of investigation, and providing research experiences for undergraduate students. Connections with secondary school educators are reached through an ASM High School Teachers Camp. As well, they are pursuing a new masters mentoring program for students from minority serving institutions. It is expected to have a dual benefit - on one hand, students are gaining insight into scientific research, and on the other hand, faculty are better-positioned to proactively recruit underrepresented minorities and women into doctoral programs in science and engineering.TECHNICAL DETAILS: The objective of this research is to develop composite battery electrolytes that exhibit high Li+ conductivity, that are mechanically rigid enough to suppress lithium dendrite growth and safely separate electrodes in self-supporting device structures, and that possess an electrochemical stability range wide enough to accommodate large electrode potential differences. While high ionic conductivity and transference numbers are important for the charge-discharge rates of batteries, stiffness and electrochemical stability are essential for taking advantage of the full redox potential of Li metal, and thus increase the gravimetric capacity of energy storage for these devices. A combination of molecular simulation-based predictive design, hybrid organic-inorganic sol-gel synthesis, in situ monitoring of microstructural developments using inelastic light scattering, and dielectric impedance measurements is used to systematically explore materials chemistries and building block functionalities for the creation of nano-porous heterogeneous electrolytes. By targeting enhanced stiffness, geometrically optimized Li+ migration paths, minimal dissipative coupling between cation and donor, and tunable redox potentials, these hybrid network structures are designed to exhibit unsurpassed performance as rechargeable battery electrolytes.

非技术性描述：储能是可持续和可再生能源技术以及移动的信息系统的一个关键方面。 虽然阳极和阴极的化学性质决定了可以存储在给定尺寸的电池中的能量的量，但隔膜材料（或电解质）控制其充电循环速率、寿命和结构完整性。 负责电化学转化的离子的高电导率（例如，锂）有利于高功率释放和短的再充电时间。 电解质和电极材料之间的化学相容性防止了会抑制电化学过程的阻挡层的形成。 电解质的机械刚性抑制枝晶生长，枝晶生长可使装置短路并导致灾难性故障（例如，自燃）。 不幸的是，这些性能标准依赖于相互矛盾的材料特性，挑战在于设计一种最大化所有这些属性的复合结构。 在这项研究中，基于模拟的预测设计，先进的材料合成方法，微观结构表征和性能监测相结合，开发新的复合电解质具有无与伦比的性能。 该项目通过培训一名博士生将实验和计算工具相结合进行调查，并为本科生提供研究经验，以创新的方式促进人力资源的开发。通过ASM高中教师营与中学教育工作者建立联系。 同时，他们正在为来自少数民族服务机构的学生实施一项新的硕士指导计划。 预计它将带来双重好处--一方面，学生可以深入了解科学研究，另一方面，教师可以更好地主动招募代表性不足的少数族裔和女性进入科学和工程博士课程。技术详细信息：本研究的目的是开发具有高Li+电导率的复合电池电解质，其具有足够的机械刚性以抑制锂枝晶生长并安全地分离自支撑器件结构中的电极，并且其具有足够宽的电化学稳定性范围以适应大的电极电势差。 虽然高离子电导率和迁移数对于电池的充电-放电速率是重要的，但是刚度和电化学稳定性对于利用Li金属的全氧化还原电势是必不可少的，并且因此增加这些装置的能量存储的重量容量。 基于分子模拟的预测设计，混合有机-无机溶胶-凝胶合成，原位监测微结构的发展，使用非弹性光散射和介电阻抗测量的组合被用来系统地探索材料化学和构建块功能的创建纳米多孔非均相电解质。 通过增强刚度、几何优化的Li+迁移路径、阳离子和供体之间的最小耗散耦合以及可调的氧化还原电位，这些混合网络结构被设计为表现出作为可充电电池电解质的卓越性能。