Laser Welding in New Energy Batteries

At present, the trend of reducing non-renewable energy is becoming more apparent. Based on the advancement of science and technology and the gradual intelligentization of industry, the concept of new energy came into being. New energy technology is being continuously applied in various industries. For the most fuel-intensive automotive sector, it is extremely urgent to use new energy instead of oil energy. Major auto manufacturers are constantly increasing their R&D investment in new energy vehicles. From the introduction of new energy vehicles to the present, it has been fruitful, and new energy buses and automobiles have been applied to actual life. The high-tech places in the new energy vehicles are power batteries. In order to ensure the stable and sustainable use of new energy batteries, laser welding has become an inevitable choice in the field of power batteries.

With the in-depth development of new energy vehicles, welding equipment is constantly being applied to production. The laser welding machine is mainly used for welding the power battery module connecting piece. It applies laser light to the area to be processed, and then forms a heat source area. The heat energy allows the soldered area to melt and then cool and crystallize to form a consolidated solder joint or weld to achieve the purpose of soldering. There are more than a dozen steps in the production of a lithium battery, and the role of the laser welding machine is to provide customers with a complete set of lithium battery production equipment to ensure the cruising range and safety of the battery during operation.

The laser welding energy is concentrated, the welding efficiency is high, the machining precision is high, and the weld seam has a large aspect ratio. The laser beam is easy to focus, align, and guided by optical instruments and can be placed at an appropriate distance from the workpiece to be re-guided between fixtures or obstacles around the workpiece. During the working process, the heat input of the laser beam is small, the heat affected zone is small, and the residual stress and deformation of the workpiece are small to achieve the purpose of precise welding. Since the battery of the power battery follows the principle of “lightweight”, the material is generally aluminum alloy and thin, so the general shell, cover and bottom are basically required to reach 1.0 mm or less. The current basic material thickness of mainstream manufacturers is 0.8 mm. Left and right, it is necessary to weld these sheets together using laser welding.

Nowadays, with the advancement of technology, laser micromachining can realize more and more functions, such as precision drilling, fine cutting, selective material removal, etc., and more new applications, new concepts are being proposed and practiced. And import industrial production. Laser is an ideal tool for micro-precision machining of various materials. It has no direct force on the workpiece and is not easy to damage the product. CAD drawings are imported quickly and easily. For some applications, it is unparalleled in high efficiency (such as dense drilling). Etc.), there are no advantages such as emissions and waste, and environmental protection.

Laser cutting uses a focused high-power-density laser beam to illuminate the workpiece, causing the irradiated material to rapidly melt, vaporize, ablate, or reach a burning point, while blowing the molten material through a high-speed airflow coaxial with the beam, thereby cutting the workpiece. open. Laser cutting is one of the hot cutting methods. There is no contact between the torch and the workpiece during laser cutting, and there is no wear of the tool. To machine parts of different shapes, there is no need to change the "tool", just change the output parameters of the laser. The laser cutting process has low noise, low vibration and no pollution.

There are two methods for laser glass cutting: one is the melt cutting method, which uses the glass to have good plasticity and ductility at softening temperature, and is irradiated to the softened glass surface with a focused CO2 laser or ultraviolet laser. The higher energy density causes the glass to melt, and then the molten glass is blown away by the air stream to create a groove, thereby achieving melt cutting of the glass. The second is the crack control method, which is a commonly used laser cutting method. Laser heating of the glass surface, higher energy will cause the temperature of the place to rise sharply, the surface produces a large compressive stress, but the compressive stress will not cause the glass to rupture; the region is sharply cooled, generally adopted Cooling gas or coolant, a sharp temperature drop will cause a large temperature gradient and a large tensile stress on the glass surface. This tensile stress will cause the glass surface to start to rupture along the direction of the predetermined scribe line to realize the glass cutting.