电—机械冲击耦合载荷下锂离子电池多尺度失效机理研究

The safety and capacity fatigue have greatly limited the rapid development of lithium-ion battery (LIB) and related industries. The failure of internal materials/structure caused by mechanical and electrochemical shock is an important reason to cause the safety and capacity fatigue problems of LIB. The coupled load conditions are inevitable for LIB in the carriers represented by new energy vehicles. The two kinds of loads are applied to different scales and physics which lead to complex multiscale and multiphysics problems. This project is focused on the multiscale failure mechanism of LIB upon electro-mechanical shock coupled load conditions, and the research contents are as follows.(1) Experimental study on dynamic mechanical and electrical load of component materials of LIB;.(2) Establish a multiscale electro-mechanical coupling model of LIB considering dynamic effects;.(3) The study of multiscale failure behavior and mechanism under coupled electro-mechanical shock load..Reach targets to clarify the failure modes and mechanisms of various scales under coupled load conditions, develop the frontier theory of dynamic multiscale mechanical behavior of LIBs, and break through the bottleneck of multiscale electro-mechanical coupling computational model. Results may enrich the frontier theories of dynamic constitutive models and multiphysics coupling. and lay a strong foundation for design high safety and service life of LIB.

电池的安全和性能衰退问题极大的限制了电池及相关产业的快速发展。机械冲击（跌落、碰撞、震动等）和电冲击（快速充/放电、短路等）引发的内部材料/结构失效是导致电池安全和性能衰退问题的主要原因。在以新能源汽车为代表的锂电池载体中，耦合工况是不可避免的。两种载荷作用尺度和物理场均不一样，这将导致复杂的多尺度和多物理场问题，本项目针对电—机械冲击耦合载荷下锂电池多尺度失效机理开展如下研究：.（1）锂电池组分材料动态力学载荷及电载荷实验研究;.（2）建立考虑动态效应的锂电池多尺度力—电耦合模型;.（3）电—机械冲击耦合载荷下多尺度失效行为与机理研究。.研究将阐明耦合载荷工况下各尺度的失效模式和机理，发展锂电池动态多尺度力学行为前沿理论，突破多尺度力—电耦合数值计算模型瓶颈。研究将丰富动态本构及多物理场相关理论，从而为工程设计高安全、高使用寿命锂电池奠定基础。

电池的安全和性能衰退问题极大的限制了电池及相关产业的快速发展。机械冲击（跌落、碰撞、震动等）和电冲击（快速充/放电、短路等）引发的内部材料/结构失效是导致电池安全和性能衰退问题的主要原因。在以新能源汽车为代表的锂电池载体中，耦合工况是不可避免的。两种载荷作用尺度和物理场均不一样，这将导致复杂的多尺度和多物理场问题，本项目针对电—机械冲击耦合载荷下锂电池多尺度失效机理开展如下五个方面的研究内容.（1）微观尺度下电极颗粒（硅）裂纹数值计算方法;.（2）商用电池中硅/石墨复合阳极多尺度多物理场计算模型;.（3）商用软包电池的均质化建模方法.（4）机械滥用下锂离子电池短路机理的多物理场理解.（5）从材料-结构的角度理解锂离子电池安全的标准和设计.通过这些研究，模型将对电池单体、模组的安全设计提供丰富的理论指导，累计发表SCI论文12篇，授权实用新型专利3项目，并与企业开展了多个横向课题的研究，实现模型的推广应用。