Collaborative Research: Mechanical and Electrical Reliability Maximization of Rechargeable Lithium-Ion Batteries through Microstructure Design

该奖项的研究将：1)开发和实验验证数值模型，以模拟任意几何形状的真实可充电锂离子电池电极；2)等温化学应力建模和设计，以改进电极电池材料和设备；3)开发解决局部焦耳加热产生的模型，以创建改进的电极几何形状。在每个推力中，微结构将使用与其长度尺度相适应的成像方法(共焦显微镜、扫描电子显微镜和原子力显微镜)来表征，以获得每个相(活性材料、粘结剂、导电添加剂、孔隙率)被分解的图像，从而通过数值模拟指导实验来实现详细的模型验证和改进的电池设计。本研究的结果将为新兴的电化学技术，如可充电电池和NASTIC结构(电化学致动器)奠定基础。通过了解导致系统局部机械、电气和热疲劳的机制，可以制造可靠性显著提高的设备。通过了解微观结构、局部焦耳加热、晶体各向异性和Vegard应力之间的关系，将开发出可靠的更高功率密度。拟议研究的各个组成部分将被整合到一个教育计划中，该计划将把通过这项研究形成的基本电化学概念整合到本科生和研究生班级中，这些班级的重点将是引导未来几代材料工程师对电化学材料和器件进行详细的理解。

The research of this award will: 1) develop and experimentally validate numerical models to simulate real rechargeable lithium-ion battery electrodes of arbitrary geometries; 2) Isothermal chemical stresses modeling and design for improved electrode battery materials and devices; 3) Development of models that resolve the local Joule-heating generation to create improved electrode geometries. In each thrust, microstructures will be characterized using imaging methods appropriate to their length scale (confocal microscopy, SEM, and AFM) to obtain images where each of the phases (active material, binders, conductive additive, porosity) is resolved to enable detailed model validation and improved battery design by guiding the experiment through numerical simulation.The results of this research will build fundamental understanding for emerging electrochemical technologies, such as rechargeable batteries and nastic structures (electrochemical actuators). By understanding the mechanisms leading to the local mechanical, electrical, and thermal fatigue of the system, devices with dramatically improved reliabilities can be manufactured. By understanding the correlations between microstructure, local Joule heating, crystallographic anisotropy, and Vegard stresses, reliable higher power densities will be developed. The individual components of the proposed research will be integrated into an educational plan that will integrate the fundamental electrochemistry concepts developed through this research into undergraduate and graduate classes whose focus will be to lead future generations of materials engineers to develop a detailed understanding of electrochemical materials and devices.