Thermo-Chemo-Mechanics and Failure of Electrode Particles in Lithium-Ion Batteries

除了作为便携式电子设备中的领先能量存储系统之外，（混合）电动车辆的出现极大地增加了锂离子电池的使用。锂离子电池应用中的主要挑战是有限的寿命沿着对高容量电极材料的需求。近年来，新的正极和负极材料出现，以取代传统的电极在锂离子电池。然而，由于复杂的热-电-化学-机械相互作用，这种电极的理论容量不能被充分利用，这导致在充电-放电循环下的快速降解和断裂。锂离子电池中高性能电极颗粒的计算设计需要准确描述多物理相互作用，导致颗粒破裂是电池退化的主要原因。该研究项目的目标是为复杂的热化学力学和电极颗粒的断裂发展有效的理论和数值基础。目标是为阳极和阴极电极颗粒开发先进的理论和计算框架。基于新的变分原理的严格开发，多物理体响应耦合与创新的相场描述的断裂。统一的连续物理框架将涵盖电化学扩散现象、相分离、加热、有限应变下的弹性和塑性变形以及由不断发展的裂纹引起的退化效应。该项目旨在为锂离子电池中高性能电极颗粒的可靠模拟设计提供模型。

In addition to being the leading energy storage systems in portable electronic devices, the advent of (hybrid) electro vehicles has increased the use of lithium ion batteries tremendously. Main challenge in applications of lithium ion batteries is the limited lifetime along with the need for high capacity electrode materials. In recent years, new anodic and cathodic materials emerged to replace the conventional electrodes in lithium ion batteries. However, the theoretical capacity of such electrodes cannot be fully utilized due to complex thermo-electro-chemo-mechanical interactions, which lead to rapid degradation and fracture under charge-discharge cycles. The computational design of high performance electrode particles in lithium-ion batteries necessitates accurate descriptions of multi-physical interactions, leading to cracking in particles as a main cause of battery degradation. This research project targets the development of efficient theoretical and numerical foundations for the complex thermo-chemo-mechanics and fracture of electrode particles. Goal is the development of an advanced theoretical and computational framework for anodic and cathodic electrode particles. Based on a rigorous exploitation of new variational principles, the multi-physics bulk response is coupled with innovative phase field descriptions of fracture. The unified continuum-physical framework to be developed will cover the phenomena of electro-chemical diffusion, phase segregation, heating, elastic and plastic deformations at finite strains, and the degradation effects resulting from evolving cracks. The project intends to deliver models for a reliable simulation-based design of high performance elctrode particles in lithium ion batteries.