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充电电池的发展突显了一个巨大的挑战：Li金属具有高度的化学腐蚀性和对周围固体成分的机械应力，导致电化学和机械不稳定性。该项目包括设计一种固态电池体系结构的基础研究，在该体系结构中，锂金属充当电化学循环过程中起伏的“工作液”，最大限度地减少电化学腐蚀和机械应力产生。来自该项目的见解可能会导致更安全和更高密度的全固态锂金属电池。此外，在这个项目中，将在多学科背景下对不同的学生群体进行培训，并加强代表不足的少数群体对科学和工程以及机械电化学，特别是宾夕法尼亚州立大学和麻省理工学院的科学和工程以及机械电化学的参与。锂金属是一种软晶体，表现出类固体的位移行为或类流体的扩散行为。锂金属还具有化学侵略性，导致固体电解质分解，消耗活性锂库存，并导致固体-电解质界面无法控制的增长。因此，在化学和机械双重侵蚀性驱动力的作用下，锂金属阳极面临应力腐蚀开裂，使得与锂金属的稳定接触具有挑战性。为了克服这些限制，本项目旨在构建一种由离子-电子混合导体(MIEC)和电子和锂离子绝缘体(ELI)组成的三维(3D)锂金属基质。该项目将通过集成多方面的实验表征和多尺度计算建模来开发基于3D MIEC/ELI的电池的设计原则。在实验上，将采用原位透射电子显微镜(TEM)直接观察复合结构中锂的沉积/剥离，并扩大到电池单元水平的测试。在计算上，分子动力学和多场连续能级模型将被耦合来模拟Li的沉积/剥离，并识别主要的界面过程。这种深入的描述和理解将为基于3D MIEC/ELI的锂金属电池的优化提供指导，使其具有更好的循环性能。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.