Chemomechanical modeling of lithiation-induced failure in high-volume-change electrode materials for lithium ion batteries(锂离子电池电极材料锂化过程中高容量变化诱发故障的化学力学建模)
Sulin Zhang
npj Computational Materials 3, Article number: 7 (2017)
doi:10.1038/s41524-017-0009-z
Published online:17 February 2017
Abstract| Full Text | PDF OPEN
摘要:近二十年来,对高效储能系统需求的快速增长,极大地刺激了大容量、高功率、耐使用的锂离子电池的研发。高容量电极材料因在电化学循环期间体积变化较大,引起材料不可避免的降解、失效,导致电池容量快速下降、循环寿命不高。本综述针对锂离子电池高容量阳极材料的降解机制,系统整理了这一机制的连续-电平计算建模的最新进展。据此,我们以硅(Si)为例,重点关注了降解过程中电化学动力学和机械应力之间的强耦合,进一步提出该耦合现象可以通过多种材料设计措施予以控制,减轻材料的降解,这些有效措施包括表面涂层、孔隙率调控等。建模结果得到了实验数据的验证,为高性能锂离子电池工程学、故障诊断和性能优化奠定了基础。
Abstract: The rapidly increasing demand for efficient energy storage systems in the last two decades has stimulated enormous efforts to the development of high-capacity, high-power, durable lithium ion batteries. Inherent to the high-capacity electrode materials is material degradation and failure due to the large volumetric changes during the electrochemical cycling, causing fast capacity decay and low cycle life. This review surveys recent progress in continuum-level computational modeling of the degradation mechanisms of high-capacity anode materials for lithium-ion batteries. Using silicon (Si) as an example, we highlight the strong coupling between electrochemical kinetics and mechanical stress in the degradation process. We show that the coupling phenomena can be tailored through a set of materials design strategies, including surface coating and porosity, presenting effective methods to mitigate the degradation. Validated by the experimental data, the modeling results lay down a foundation for engineering, diagnosis, and optimization of high-performance lithium ion batteries.