Laser welder welding process for rectangular aluminum shell battery

Laser welder welding process for rectangular aluminum shell battery

The market share of lithium battery aluminum case is higher than that of aluminum case, which is determined by the advantages of high toughness, light net weight and high safety factor of aluminum case. The cover plate of the rectangular battery case must be welded.Welding is a very important manufacturing process.The choice of welding method and welding process directly affects the cost, quality, safety and consistency of the battery Among the many welding methods, laser welding has the following features.Introduces the welding process of rectangular aluminum shell batteries using a laser welding machine.

The square battery case has a rectangular cover plate on top and the board contains the positive leadout end.Insert the cover plate into the case so it is flush with the top opening and use the laser and place a square gap Repeat the operation between the cover plate and the case.Use the laser method to weld the sealing.The whole process of welding is called top welding.During the top welding, the laser can't move and the rechargeable battery can be fixed. After the laser is aimed at the weld, activate the console to move the rechargeable battery along the X and Y coordinates of the console to the weld and Get rid of the same square pattern. When the cover plate of the prismatic battery uses top welding seal structure processing technology, there is no precise positioning step in the placement of the cover plate, the length and length standard tolerances are tighter, and the welding and installation accuracy requirements are tighter. It's getting expensive.

To ensure the seam-forming effect of high-speed laser welding of the top cover, the following requirements must be met:

1. The weld seam is wide enough and the aspect ratio of the weld seam is appropriate. This requires that the light source has a sufficiently large heating range and the energy of the weld line is within a reasonable range.

2. The weld is smooth and requires sufficient heat cycle time for the welding process to have sufficient fluidity in the molten pool, and the weld solidifies into a smooth metallic weld under the protection of the shielding gas. .

3. The weld seam has good consistency, less porosity and holes, so the laser must act stably on the workpiece during the welding process, and the high-energy beam plasma is continuously generated, and the melt pool acts inside the The molten pool is generated under the plasma reaction force "keyhole", the keyhole is large enough and stable, so that the generated metal vapor and plasma are not easily atomized, pulling out the metal droplets and splashing , and the surrounding molten pool keyhole is not easily crushed and is not easily caught in the gas.

The shell materials of power batteries are mainly aluminum alloys and stainless steels, among which aluminum alloys are most commonly used, generally 1 series and 3 series aluminum alloys. In actual production, suitable laser and welding process parameters should be selected according to the battery material, shape, thickness, tension requirements, etc., such as welding speed, waveform, peak value, and angle of inclination of the welding head. Reasonable welding process parameters can be set to ensure the final welding effect and meet the requirements of power battery manufacturers.

Advantages of Laser Welder in Welding Square Aluminum Shell Battery:

1. Since most of the laser power is injected into the dynamic keyhole, externally scattered laser light is reduced, so only a small amount of laser power is required and the welding heat input is relatively low (30 %Few). , reduce equipment losses and energy losses.

2. The swing welding method is highly adaptable to the assembly quality of workpieces and reduces defects caused by problems such as the assembly process.

3. The swing welding method has a strong repair effect on the weld seam hole, and the yield of repairing the cell weld seam hole is very high.

4. Laser welding can be precisely controlled, the focus spot is small, high-precision positioning is possible, and the mechanical arm is easy to realize automation, improving welding efficiency, reducing man-hours, reducing costs, and simplifying the system. , easy to debug and maintain the equipment.

The above is the process of welding a square aluminum shell battery with a laser welding machine.In the process of manufacturing and assembling a square aluminum shell lithium battery, the battery cell soft connection and cover plate welding, sealing nail welding, etc. Laser welding is the main welding method for prismatic power batteries, with laser welding, it has many advantages such as high energy density, high output stability, high welding precision and easy system integration. Lithium batteries are an irreplaceable choice.