28 / 2022-03-01 22:40:14

Study on Microstructure and Performance of Electromagnetic Pulse Welding of Lithium Battery Laminated Workpieces Based on Through-hole Structure

Electromagnetic pulse welding,Laminated workpiece,lithium battery,through-hole structure,tab

Laminated workpieces such as tabs and battery cover plates are the key part for energy transmission of lithium batteries, and the quality of the connection between the workpieces determines their performance and safety. Electromagnetic pulse welding (EMPW) of lithium battery laminate workpieces can improve tensile strength and reduce contact resistance of the joint, however, only low-efficiency welding is possible. A through-hole structure with gradient characteristics is proposed to assist EMPW in this work, so that the collision sequence of the electromagnetic force-driven flyer plate and the tab is reversed, and laminated workpieces synchronous welding is realized. To verify the reliability of the method, an experimental platform for EMPW of the stacked tabs has been established to welded the laminated workpieces. The results show that when the discharge voltage is 13kV, the Al drive plate and the Al battery cover plate are welded and tightly combined with the laminated tabs. SEM analysis results show that metallurgical bonds are formed between the Al plates, tabs, and between the tabs and the Al plate. A special corrugated interface produced by EMPW was also observed in the bonding area of tabs and Al plate, which increased the contact area, improved tensile strength and reduced contact resistance. This work provides a theoretical basis and experimental support for EMPW of lithium battery stack tabs.