高容量锂离子电池负极集流体泡沫铜的环境疲劳行为、损伤机理及寿命模型

项目名称： 高容量锂离子电池负极集流体泡沫铜的环境疲劳行为、损伤机理及寿命模型

项目编号： No.51471036

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 陈荐

作者单位： 长沙理工大学

项目金额： 84万元

中文摘要： 高容量锂离子电池新型Si、Ge、Sn基负极材料在充放电过程中产生巨大体积变化，致使电池循环性能下降，是制约其发展的瓶颈；以泡沫铜替代铜箔作为负极集流体能起到良好的缓冲作用，但在服役过程中易产生疲劳损伤。本项目以三维网状结构泡沫铜为研究对象，研究在循环应力、电解液、极化电位多因素交互作用下的环境疲劳行为；通过材料内部应力状态、微结构演变及电化学特性分析，阐明循环载荷下塑性应变累积及应变带演化规律和孔棱裂纹萌生与扩展过程，明晰电化学-力学交互作用机制，揭示泡沫铜的环境疲劳损伤机理；研究微观结构演化与材料性能变化之间形性演变关联，建立反映多孔结构特征、环境效应、载荷因素的环境疲劳寿命模型。为集流体泡沫铜材料的设计及在锂离子电池负极中的应用提供科学依据，同时对丰富多孔金属材料的疲劳理论体系具有重要意义。

中文关键词： 环境疲劳；寿命模型；损伤机理；负极集流体；泡沫铜

英文摘要： In high capacity lithium ion battery, great volume variation of anode based on Si, Ge or Sn during the process of charge/discharge decreases cell performance significantly. Copper foam as the anode current corrector can favorablely buffer the volume variation compared with common copper foil. However, environmental fatigue damage is unavoidable for copper foam in the service process. In this regard, the project will investigate the environmental fatigue behavior of copper foam with three-dimensional network structure under the interaction of cycle loading, electrolyte and polarization potential. Combined with the analysis of internal stress, microstructure evolution and electrochemical characteristics, the plastic strain accumulation, strain evolution and microcrack initiation and propagation process under cyclic loading will be clarified, the electrochemical -mechanical interaction mechanism will be analyzed, the environmental fatigue damage mechanism of copper foam will be discovered. Based on the relationship between microstructure evolution and properties diversification, an environmental fatigue life model which reflects the pore structure characteristics, environment effect, loading factor will be established. This project will provide a scientific basis for the design of collector copper foam material and will supply an experimental support for its application in the anode of lithium ion battery. It also has important meaning to enrich the fatigue theoretical system of porous metal materials.

英文关键词： Environmental Fatigue;Life Model;Damage Mechanism;Anode Current Collector;Copper Foam