Why Is Laser Welding Technology Used for Rechargeable Button Cells?

In recent years, new rechargeable button batteries have become incredibly popular in various small wearable devices, such as hearing aids, electronic tags, GPS devices, sensors, smartwatches, smart glasses, and smart speakers. These batteries offer advantages like long running time, high security, and customization.

Also known as button cells or rechargeable coin cells, these batteries are notable for their consistency, and they don't suffer from bulging issues during charge and discharge cycles. They can have larger capacities and be directly laminated onto PCB boards. The latest rechargeable button cells support fast charging technology, making them suitable for special applications. They are environmentally friendly and can be recharged and reused.

As the 3C electronics industry continues to develop, customers have higher expectations for battery safety. This demand has led to higher requirements for production line equipment. Consequently, most rechargeable steel-cased coin cell batteries on the market today use laser welding technology. But why is this technology used for these batteries?

Laser Welding Application Process for Button Batteries:

Shell and Cover: Laser etching of the button steel shell.

Cell Segment: Welding of the coil core’s positive and negative poles and the shell cover, shell cover to shell laser welding, and sealing nail welding.

Module PACK Section: Cell screening, side gluing, positive and negative pole welding, post-welding inspection, dimensional inspection, application and removal of adhesive paper, air tightness inspection, and sorting.

Reasons for Using Laser Welding Technology for Rechargeable Steel-cased Button Batteries:

Precision and Versatility: Traditional welding methods struggle to meet the high standards required for new rechargeable button batteries. In contrast, laser welding offers versatility in processing technology, handling diverse materials like stainless steel, aluminum, copper, and nickel. It can manage irregular welding trajectories, detailed welding points, and precise positioning, improving product consistency and reducing defects. Laser welding is the optimal method for button batteries.

Material Compatibility: The positive and negative electrodes and shell cover welding involve copper, a highly reflective material with low laser absorption. Due to the material's thinness, excessive heat or insufficient power density can cause deformation and poor welding. The top cover sealing welding requires precision as the shell and cover connection thickness is only 0.1mm. Traditional welding can't achieve this precision. High laser power can penetrate the battery case, damaging the internal core, while low power can't form a molten pool for effective welding.

Automatic Assembly Suitability: The pins are usually welded through the finished battery in a stacked manner. During this process, the battery is encapsulated and filled with electrolyte. Unstable welding can cause internal diaphragm damage, short circuits, electrolyte leakage, false welding, over-soldering, and other issues. Laser welding technology is ideal for automatic assembly and welding of steel-cased button batteries. Its modular design is compatible with 8-16mm button battery cell assembly, ensuring production line data traceability.

Laser welding technology equipment can handle the entire process from cell screening data upload to lamination accuracy control and welding energy detection. This technology enables fully automatic assembly welding, ensuring efficient product output. High-precision laser lamination welding technology, real-time welding monitoring technology, and visual size sorting technology guarantee high-quality welding. This approach allows for precise size control, greater reliability, and stability, achieving a welding rate of 99.5%.

The explanation above outlines why laser welding technology is used for rechargeable steel-cased button batteries. I believe this introduction has provided you with a clear understanding of the benefits of using laser welding technology in these batteries. Revolbat, a manufacturer of rechargeable button batteries, continuously upgrades and iterates its technology to form a core technology patent group.