CAREER: Safe, High-Performance Li-Ion Batteries Through a Fundamental Investigation of Thermal Transport in Electrochemical Materials and Interfaces

该项目描述了一个集成的研究和教育计划，用于测量和增强电化学储能设备（如锂离子电池）中关键材料和材料界面的热传输。锂离子电池在包括电动汽车在内的多种应用中具有优异的能量密度和电化学性能。然而，热传导不良导致的过热是一个众所周知的技术障碍，它直接阻碍了性能并导致严重的安全问题，正如最近发生在飞机和汽车电池组的火灾事件所显示的那样。迫切需要确定和减轻锂离子电池热性能差的根本原因。这可能会改变锂离子电池的性能和安全性，但由于锂离子电池在多个长度尺度上的热和电化学传输的高度耦合性质，以及在改善热传输的同时保持电化学性能的重要性，这也特别具有挑战性。这项工作将为当前和未来器件的电化学储能材料的微尺度热工程奠定基础。本工作中发展的实验和理论研究方法将适用于其他几个相关的工程系统，如超级电容器。教育和推广活动将解决本科生的学习挑战，特别是非传统的“通勤”学生和那些来自代表性不足群体的学生。本提案解决了锂离子电池中热传输不良的科学和技术相关问题，这是性能和安全的主要障碍。将建立一个独特的测试平台，能够在工作的锂离子微电池上进行现场、材料级的热和电化学实时测量。这项跨学科研究将首次通过界面化学桥接和微观结构变化来测量和增强锂金属和固态电化学器件中材料和材料界面的热传输。这些研究重点将量化关键锂离子材料的微观结构-性能-功能关系的本质。由于速率限制过程的热增强，提高了电池级的热性能，将直接导致安全和高性能的电池，这将改变能量转换的性质，运输和电子产品的应用，这是目前电池根本无法实现的。

This project describes an integrated research and education plan for measuring and enhancing thermal transport through key materials and material interfaces in electrochemical energy storage devices such as a Li-ion cell (battery). Li-ion cells offer excellent energy density and electrochemical performance in multiple applications, including electric vehicles. However, overheating due to poor thermal conduction is a well-known technological barrier, which directly impedes performance and results in severe safety concerns, as shown in recent incidents of fire in aircraft and car battery packs. There is an urgent need to identify and alleviate the fundamental material-level root cause of poor thermal behavior of Li-ion cells. This can potentially transform Li-ion cell performance and safety, but is also particularly challenging due to the highly coupled nature of thermal and electrochemical transport in a Li-ion cell over multiple length scales, and due to the importance of preserving electrochemical performance while improving thermal transport. This work will lay the foundation of microscale thermal engineering of electrochemical energy storage materials for current and future devices. Experimental and theoretical research methods developed in this work will be applicable to several other related engineering systems, such as super-capacitors. Education and outreach initiatives will address learning challenges among undergraduate students, particularly non-traditional "commuter" students and those from under-represented groups.This proposal addresses scientifically and technologically relevant problems related to poor thermal transport in Li-ion cells, which is a major impediment to performance and safety. A unique test platform capable of in situ, material-level thermal and electrochemical measurements in real time on an operating Li-ion micro-cell will be built. This interdisciplinary research will, for the first time, measure and enhance thermal transport in materials and material interfaces in Li-metal and solid state electrochemical devices through interfacial chemical bridging and microstructural changes. These research thrusts will quantify the nature of microstructure-property-function relationships for key Li-ion materials. Improved cell-level thermal performance due to thermal enhancement of rate-limiting processes will directly result in safe and high performance batteries that will transform the nature of energy conversion, transportation and electronics through applications that are simply not possible with present batteries.