Laser Welding Machine of Tabs for Small Lithium Batteries

With the increase in environmental awareness and attention to new energy vehicles, the global demand for new energy and energy storage is also growing, and the demand for lithium batteries is also increasing.

The lithium battery industry continues to grow, and the small lithium battery industry explodes at the same time. Industry forecasts indicate that global small lithium battery shipments will be nearly 220GWh in 2025.

Like the production of power batteries, in the welding and production process of small consumer lithium batteries, laser welding has also become an important processing technology on the small lithium battery production line because of its high precision, high stability and high efficiency .

01 Background

In a project of a giant company in the battery industry, the customer's requirement is a solution system suitable for laser welding of positive and negative electrode plates and PCBA pads of small lithium batteries.

At the same time, this system can also be applied to the tabs and positive electrodes of the battery core. Negative electrode welding.

The system has high requirements on material compatibility and welding quality. Taking nickel sheet welding as an example, the welding tension requirement is >3.0 KGF and the penetration depth is <0.05mm.

In terms of overall requirements, the overall yield requirement of the welding solution is ≥99.9%, and the power stability requirement is ≤±0.5%.

The specific process requirements are as follows:

✔For 4 welding points arranged in 2×2, the diameter of the solder joints must be between 0.5~0.8mm, and there must be 4 effective weld nuggets remaining after pulling.

✔The solder points must be uniform in size and must have no defects such as explosion, desoldering, weak welding, spot deviation, spot penetration, few welding points, blackened welding points, weak welding points, etc.

✔The welding surface is burr-free and looks good.

02 Solution Configuration

As for the core device, the laser source chooses to use MAX laser single-mode quasi-continuous fiber laser (QCW) 150/1500W.

This series of lasers has the advantages of high-quality laser output, high power, high efficiency, high reliability, and long life, and is suitable for Scenarios such as power battery electrode welding, mobile phone precision welding, and laser precision welding of electronic components.

The specific performance parameters of (QCW)150/1500W are as follows:

03 Summary

For different welding materials, specialized welding processes are used, combined with professional galvanometers and control software, and after multiple verifications, an "optimal solution" is obtained. The welding processes for some of the materials are as follows:

▲0.06mm nickel-plated brass -0.15mm brass

-Welding power: 75%;

-Welding mode: continuous;

-Spiral diameter: 0.55mm;

-Welding speed: 180mm/s.

▲After testing, it was concluded that during the welding of this material, the solder joint size was 0.72mm, the back mark was clearly visible, the pulling force was 9.86N, and 4 weld nuggets remained after pulling, which met the requirements.

▲ 0.06mm nickel-plated brass-0.3mm brass

-Welding power: 90%;

-Welding mode: continuous;

-Spiral diameter: 0.55mm;

-Welding speed: 180mm/s

After testing, it was concluded that during the welding of this material, the solder joint size was 0.73mm, the back mark was clearly visible, the pulling force was 10.46N, and 4 weld nuggets remained after pulling, which met the requirements.

▲ 0.06mm brass nickel plated-0.3mm nickel

-Welding power: 64%;

-Welding mode: continuous;

-Spiral diameter: 0.7mm;

-Welding speed: 800mm/s.

After testing, it was concluded that during the welding of this material, the welding point size was 0.71mm, there were no back marks, the pulling force was 9.01N, and 4 weld nuggets remained after pulling, which met the requirements.

At present, this solution has been launched at the customer's site. With the continuous advancement of lithium battery technology and the continuous improvement of environmental awareness, with lasers as the core, we provide customers with high-quality, high-efficiency one-stop laser industry solutions.