1.北京化工大学 机电工程学院;2.深圳吉阳智能科技有限公司
TK01
1.Beijing University of Chemical Technology,College of Mechanical Electrical Engineering,Beijing;2.Shenzhen Geesun Intelligent Technology Co Ltd
粘结剂作为锂电池电极制造的重要材料,它的用量虽少,却是极板力学性能的主要承担者。现有的复合电极力学行为模型多将粘结剂层假设为线弹性材料,这很难描述粘结剂层的复杂力学行为,因此为了深入理解极板纳米级颗粒与粘合剂在充放电过程的力学行为,根据已有的实验数据拟合了Neo-Hookean超弹性模型,采用与锂离子扩散方程形式相似的传热方程求解工具模拟活性硅颗粒在充电放电过程的应力变化,研究结果表明硅颗粒锂化时主要的塑性变形发生在第一个充电放电循环过程中,粘接层的最大应力变化类似纳米颗粒间的应力变化,随着粘结层厚度的增加,粘接层界面的最大应力会逐渐降低；还有,相近应变下Neo-Hookean超弹性模型对于粘结剂流变行为描述好于线弹性模型。
As an important material for lithium battery electrode manufacturing, adhesive is the main undertaker of the mechanical properties of electrode plate although its dosage is small. Most of the existing rheological models of composite electrode were assumed the binder layer as linear elastic material, which was difficult to describe the complex mechanical behavior of it. Therefore, in order to deeply understand the mechanical behavior of the electrode plate Nano particles and adhesive during the charge and discharge process, the Neo Hookean hyperelastic model was fitted based on the existing experimental data in literature. The results show that the main plastic deformation occurred during the first charge discharge cycle, and the maximum stress evolution of the bonding layer is similar to that of the nano particles. With the increase of the thickness of adhesive layer, the maximum stress at the interface of adhesive layer would decrease gradually.
