层叠式锂电池制造中金属极片的伺服超声波微焊接机理研究

项目名称： 层叠式锂电池制造中金属极片的伺服超声波微焊接机理研究

项目编号： No.51275304

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 机械、仪表工业

项目作者： 张延松

作者单位： 上海交通大学

项目金额： 80万元

中文摘要： 层叠式锂电池装配过程中金属极片连接接头的质量将显著影响电池性能的一致性。实现50层以上微米级铝/铜/镍金属极片的稳健连接是目前的瓶颈问题，原因在于超声波微焊接过程的摩擦生热、微观屈服、变形流动、加工硬化等耦合作用，介观尺度金属极片键合过程中多层接触界面间的能量累积和衰减效应显著。为此，本项目建立面向宏微耦合的伺服超声波微焊接控制方法，解决超声波微焊接过程的摩擦热效应、塑性变形尺度效应和接触界面间的Casimir力效应等关键问题。内容包括：1）建立基于塑性细观力学-流变力学的摩擦尺寸效应模型，揭示微焊接过程的超声热效应及摩擦生热机理；2）建立基于分子动力学与有限元耦合的多尺度模型，揭示介观尺度下接触区域的微塑性变形行为与材料软化机制；3）建立伺服驱动的超声波微焊接系统，实现键合压力/位移的精确控制。形成适合于50-80层异质超薄金属极片的超声波微焊接新工艺与新装备，推动锂电池制造技术的进步。

中文关键词： 超声波微焊接；介观尺度；塑性变形；摩擦生热；稳健优化

英文摘要： It's generally known that, in the assembling process of lithium battery, the joining quality of metal foil has a remarkable impact on the consistency of the battery performance. However, how to realize the robust joining of more than 50-layer micron-grade aluminum/copper/nickel foil is still a major problem. The micro mechanical behavior (i.e. friction, yield, deformation flow) in the ultrasonic micro-welding process, along with the distinct cumulative effect of the energy transfer and the micro plastic deformation at contact area during the bonding process of multilayer pole pieces are the primary reasons. Firstly, a control method oriented to macro-micro coupling for servo ultrasonic micro-welding will be developed to understand the thermal effect of ultrasound and the mechanism of frictional heat generation during ultrasonic micro-welding process. Furthermore, a multiple scale model based on molecular dynamics and finite element coupling method will be proposed to reveal the deformation behavior and the mechanism of material softening at mesoscopic level. Thirdly, a servo-driven ultrasonic micro-welding system will be built to achieve the precise control of bonding pressure and micro displacement. This project aims to address the key issues such as thermal effect, size effect of friction, plastic defor

英文关键词： Ultrasonic micro welding；Meso-scale；Plastic deformation；Friction heat；Robust optimization