Should I Choose A Spot Welding Machine Or A Laser Welding Machine for Welding The Battery Tabs of New Energy Vehicles? Which One Can Better Ensure Safety?

The tab welding of new energy vehicle batteries is a core process. As a key component for electrical conduction, the welding quality of tabs directly affects the safety and service life of the battery. Many manufacturing enterprises are caught in a dilemma of choosing between spot welding machines and laser welding machines. In fact, there is a significant difference in the safety and adaptability of the two, and the choice should be based on the characteristics of the tabs.

Let's first look at the performance of spot welding machines in tab welding. Traditional spot welding machines generate heat by applying pressure and passing electricity through electrodes to melt and weld. They are suitable for copper and aluminum tabs with a thickness of 0.1–0.5 millimeters. However, there are two key safety hazards associated with them. First, the direct contact between the electrode and the tab can easily produce electric sparks. If there is dust or electrolyte residue on the tab surface, it may cause a fire risk. Second, the heat-affected zone during welding is relatively large, which can easily lead to deformation and embrittlement of the tab. In the long run, this may cause the tab to break and lead to battery short circuits. Although the risks can be reduced by optimizing parameters, the safety of spot welding machines still has limitations when it comes to welding tabs of high-energy-density batteries.

Now let's look at the safety advantages of laser welding machines. Laser welding machines use high-energy-density laser beams to achieve contactless welding. Since there is no need for electrode contact with the tab, the risk of electric sparks is fundamentally eliminated. The laser spot diameter can be precisely controlled within 0.1–0.3 millimeters, and the heat-affected zone is only 1/5 that of a spot welding machine. This effectively reduces tab deformation and embrittlement, ensuring the stable mechanical properties of the welded joint and reducing the risk of breakage in the later stages. At the same time, the weld seam of laser welding is highly dense, which can avoid problems such as poor welding and false welding that lead to excessive contact resistance. This reduces the risk of battery bloating and fire caused by local overheating. It is especially suitable for tab welding of mainstream batteries such as ternary lithium batteries and lithium iron phosphate batteries.

In addition, the precision requirements of tab welding also affect the choice of equipment. Tabs usually need to be precisely connected with the battery cell and busbar. Laser welding machines equipped with a vision positioning system can achieve a repeat positioning accuracy of ±0.02 millimeters, ensuring the precise location of the weld seam and avoiding uneven current distribution caused by misalignment. In contrast, spot welding machines, limited by electrode wear and positioning methods, have relatively larger precision deviations, which can easily lead to safety hazards in long-term mass production.

However, laser welding machines have higher requirements for the cleanliness of the tab surface. If there is oil or oxide layer, it needs to be treated in advance, otherwise it will affect the welding quality. But from the core demand of safety, its advantages far outweigh this operational detail.

The safety of new energy vehicle battery tab welding is crucial, and the choice of equipment should not be taken lightly. The PDKJ laser welding machine has optimized the laser energy output for tab welding, with a small heat-affected zone and precise positioning. It can reduce safety hazards from the source and is compatible with tabs of different materials and thicknesses. It is a reliable choice to ensure the safety of battery welding.

If you have welding machine requirements, please contact Ms. Zhao

E-Mail: pdkj@gd-pw.com

Phone: +86-13631765713