Welding is a critical step in lithium battery pack assembly. The quality of the weld directly impacts the performance and lifespan of the battery pack. This guide explains essential welding techniques, focusing on connecting leads and nickel strips to cylindrical, prismatic, and pouch batteries.

Common Lithium Battery Welding Methods

1. Spot Welding (Resistance Welding)

Spot welding is a traditional and widely used method, especially for connecting nickel strips in cylindrical batteries. It works by applying a strong electric current through the materials, generating heat through electrical resistance. This process causes the materials to melt and form a secure connection.

Applications:

• Cylindrical steel-cased cells (e.g., 18650 batteries)

• Small electric vehicles

• Household appliances

• Energy storage battery packs

Advantages:

• Cost-effective

• Reliable for small to medium-scale applications

2. Laser Welding

Laser welding uses a high-intensity laser beam to create a focused heat source, melting the material to form precise welds. This method is particularly suitable for prismatic aluminum-cased batteries and pouch batteries due to its precision and ability to handle delicate materials.

Applications:

• Prismatic aluminum-cased batteries

• Pouch battery packs

• Electric vehicle battery modules

• Large-scale energy storage systems

Advantages:

• High precision

• Minimal heat impact on surrounding materials

• Ideal for complex or delicate assemblies

  

Choosing the Right Welding Technique

Selecting the appropriate welding method depends on the battery type:

• Cylindrical Batteries: Use spot welding for reliable and robust connections.

• Prismatic and Pouch Batteries: Laser welding provides higher precision and is better suited for handling thin materials.

Conclusion

Understanding lithium battery welding techniques is essential for producing reliable and safe battery packs. Whether using spot welding for cylindrical cells or laser welding for prismatic and pouch cells, choosing the right method ensures optimal performance and longevity.

At SUNKA LEAD, we offer advanced battery welding equipment, including spot welders and laser welders, to support your battery assembly needs. Explore our range to enhance your production efficiency and quality.