充放电过程中锂离子电池负极铜集流体的电化学和力学行为研究

Electrochemical and Mechanical Behavior of Copper Current Collector of Lithium Ion Battery Negative Electrode during Charge and Discharge

使用化学还原法结合聚吡咯软模板法制备了锑纳米颗粒@聚吡咯网络结构负极材料,对不同循环圈数后铜集流体的结构和不同温度下循环50圈后铜集流体的电化学和力学行为进行研究。结果表明,随着循环圈数的增加,铜集流体粉化层的厚度也会增加;0℃和60℃下循环50圈后铜集流体的弹性模量和硬度相比于原始集流体都有明显的降低,可能是由于Li、Sb和C扩散到集流体中形成的不溶体具有强化作用;而20℃下铜集流体的弹性模量和硬度有轻微的增加,说明其比原始集流体脆性增大,韧性下降,由此表明温度对电池的放电性能有显著影响。

Sb nanoparticle@polypyrrole network structure anode material was fabricated by chemical reduction method combined with polypyrrole soft template method,the structure of Cu substrate and its mechanical behavior after different temperature cycles were studied.The results show that as the number of cycles increases,the thickness of Cu substrate powdered layer increases.After 50 cycles at 0℃and 60℃,the Young’s modulus and hardness of the Cu substrate are significantly lower than those of original Cu current collector,which might be due to the strengthening effect of the insoluble substance resultant from the dispersion of Li,Sb and C into the current collector.The Young's modulus and hardness of Cu substrate at 20℃increase slightly,indicating Cu substrate is more brittle and less tough than original Cu current collector,thus indicating that temperature has a significant effect on the discharging performance of the battery.