锂离子电池化学反应-相变-变形耦合、开裂和分层的研究

项目名称： 锂离子电池化学反应-相变-变形耦合、开裂和分层的研究

项目编号： No.11332005

项目类型： 重点项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 张俊乾

作者单位： 上海大学

项目金额： 315万元

中文摘要： 锂离子电池是当前最受关注、最有前景的动力电池技术。电极开裂和分层等损伤是导致锂电池储能能力降低与寿命缩短的主要原因之一。本项目以锂离子电池的电极材料/结构为对象，针对高储能密度锂离子电池中扩散应力诱导的损伤和破坏问题，以理解变形、开裂和分层机理，以及揭示它们的时间-空间演化规律为重点，发展“电化学反应－锂化相变－应力”耦合问题的相场模型及模拟方法，研究电极结构变形、裂纹及分层的时间-空间演化的分析方法，进而，根据实际材料寻找优化的电极结构设计方案和优化的充放电规程，并进行实验验证。通过本项目的研究，不仅可以从理论上掌握锂离子电池电极由充放电产生损伤的过程，而且可以从实际结构设计和日常充放电操作规程上避免损伤的产生。因此，不但是一个非常重要的科学问题，而且对于实际工程应用也具有较大的价值

中文关键词： 锂离子电池;分层;裂纹;相变;电化学反应

英文摘要： Among the available battery technologies to date, lithium ion battery is one of the most promising technologies that meet the both requirements of energy density and power of electric vehicles. Damage in electrodes, such as cracking and delamination, is one of main causes which lead to fade in capacity and deterioration in cycle performance. This proposal aims to investigate the damage and failure caused by the diffusion induced stress in lithium ion batteries, to understand the mechanisms of deformation, cracking and delamination and to predict the spatial-temporal evolution of deformation, cracking and delamination. The phase-field model and simulation method will be developed to solve the coupling problems of stress, phase transformation and electrochemical reaction. The methodology, which takes into account phase transformation and electrochemical reaction, will be proposed to predict evolution of deformation, cracking and delamination. Based on the developed methods the performance of real lithium ion batteries will be simulated and the design insights into material selection, structural configuration of electrodes and charging procedures will be provided. The experiments will be conducted to verify the theoretical analysis and numerical simulation. This study would not only improve our understanding of the mechanisms of damage process, but also provide tools for design of structural configuration and charging operations to avoid the damage.

英文关键词： Li-ion batteries;delamination;cracking;phase transformation;electrochemical reaction