Welding method of current collators for high-capacity lithium ion power batteries

Abstract

The invention relates to the technical field of manufacture of lithium ion batteries, in particular to a welding method of current collators for high-capacity lithium ion power batteries. The method includes the steps of firstly, performing ultrasonic welding to a current collector part; and secondly, performing additional laser welding to non-ultrasonic-welding spot areas on a surface textured by ultrasonic welding. The two welding techniques are applied perfectly, welding strength and contact area of connections of the current collector for high-capacity lithium ion power batteries are increased, advantages of the two welding techniques are integrated, and the defects caused by single ultrasonic welding or single laser welding are made up or eliminated. The two welding techniques are harmonically unitized for production of the high-capacity power batteries, various safety problems such as poor quality and subsequent using problems caused by poor quality in traditional single ultrasonic welding or laser welding are avoided, and reject ratio, scrappage and safety hazards are decreased.

Description

technical field [0001] The invention relates to the technical field of manufacturing lithium-ion batteries, in particular to a method for welding current collectors of large-capacity lithium-ion power batteries. Background technique [0002] With the global energy crisis and environmental pollution becoming more and more serious, the search for green and sustainable new energy has become the main development direction of the energy field. As an energy-saving and environmentally friendly new energy vehicle, electric vehicles are developing rapidly. Lithium-ion batteries have become one of the power sources that have attracted much attention due to their advantages such as high energy density, long cycle life, green and pollution-free. The welding process of current collector parts has become the top priority in the battery assembly process. Poor welding here is likely to cause various quality problems. In the case of vibration, extrusion, sudden temperature rise, and excessiv...

AI Technical Summary

Problems solved by technology

However, the welding strength of ultrasonic welding is affected by factors such as the thickness of the workpiece, the wear and tear of the welding machine, the nonlinear reduction of output power, and the difficulty of quality control and inspection. The welding effect of the current collector of large-capacity batteries has not been satisfactory.

[0004] A small number of manufacturers in the industry use laser welding for current collector components. Laser welding has the advantages of high welding strength, less susceptible to environmental interference, and no contact with workpieces. High single point energy leads to low welding efficiency, small welding area leads to poor overcurrent performance, etc.

[0005] In summary, it can be seen that after the current collector components are welded by pure ultrasonic welding or pure laser welding, there are some specific defects, and the comprehensive performance such as overcurrent performance, rate performance, and tensile performance is difficult to balance, and it is difficult to achieve High-performance requirements such as high current and low temperature rise in the actual use of large-capacity batteries