Collaborative Research: Creep-enabled 3D solid-state Lithium-metal batteries

基于锂（Li）金属电镀和剥离的全固态可充电电池的发展凸显了一个巨大的挑战：锂金属具有化学强腐蚀性，对周围的固体成分具有机械应力，导致电化学和机械不稳定。该项目包括设计固态电池结构的基础研究，其中锂金属作为“工作流体”在电化学循环过程中上升和下降，最小的电化学腐蚀和机械应力产生。从这个项目中获得的见解可能会导致更安全、密度更高的全固态锂金属电池。此外，在这个项目中，不同的学生群体将在多学科背景下接受培训，并加强被忽视的少数群体在宾州州立大学和麻省理工学院的科学和工程，特别是机电化学方面的参与。锂金属是一种软晶体，表现出类似固体的驱替行为或类似流体的扩散行为。金属锂具有化学侵蚀性，导致固体电解质分解，活性锂库存消耗，固-电解质间相生长不可控。因此，锂金属阳极在化学和机械双重侵蚀驱动下面临应力腐蚀开裂，使与锂金属的稳定接触变得困难。为了克服这些限制，该项目旨在构建一个由混合离子电子导体（MIECs）和电子和锂离子绝缘体（eli）组成的三维（3D）锂金属主机。该项目将通过综合多方面实验表征和多尺度计算建模，为基于MIEC/ELI的3D电池制定设计原则。实验上，原位透射电子显微镜（TEM）将直接观察锂在复合材料结构中的沉积/剥离，并扩大到电池级测试。计算上，分子动力学和多场连续水平模型将耦合模拟锂沉积/剥离，并确定主要的界面过程。这种深入的表征和理解将为改进循环性能的3D MIEC/ELI基锂金属电池的优化提供指导。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The development of all-solid-state rechargeable batteries based on lithium (Li) metal plating and stripping has highlighted a grand challenge: Li metal is chemically highly corrosive and mechanically stressful to the surrounding solid components, causing both electrochemical and mechanical instabilities. This project includes fundamental research to design a solid-state battery architecture in which Li metal functions as “a working fluid” rising and falling during electrochemical cycling with minimal electrochemical corrosion and mechanical stress generation. Insights from this project will potentially result in safer and higher density all-solid-state Li-metal batteries. Further, in this project a diverse group of students will be trained in a multidisciplinary setting and enhance underrepresented minority groups involvement and participation in science and engineering in general and mechanoelectrochemistry in particular at Penn State and MIT. Li metal is a soft crystal and exhibits either solid-like displacive behavior or fluid-like diffusive behavior. Li metal is also chemically aggressive, causing decomposition of solid electrolytes, consumption of active Li inventory, and uncontrollable growth of solid-electrolyte interphase. Li-metal anodes thus face stress-corrosion cracking under dual aggressive chemical and mechanical driving forces, making stable contact against Li metal challenging. To overcome these limitations, this project aims to construct a three-dimensional (3D) Li-metal host made of mixed ionic-electronic conductors (MIECs) and electronic and Li-ion insulators (ELIs). The project will develop design principles for the 3D MIEC/ELI based battery through integrated multi-faceted experimental characterization and multiscale computational modeling. Experimentally, in-situ transmission electron microscopy (TEM) will be carried out to directly observe Li deposition/stripping in the composite structure and scale up to battery-cell level testing. Computationally, molecular dynamics and multi-field continuum-level models will be coupled to simulate Li deposition/stripping and identify the dominant interfacial processes. Such an in-depth characterization and understanding will offer guidance to the optimization of the 3D MIEC/ELI based Li-metal batteries with improved cycling performance.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.