Laser cleaning is a new cleaning method that has been increasingly used in the battery industry in recent years with the development of laser cleaning. The transportation and handling of batteries prior to the welding process can introduce contaminants and generate oxides. Especially when the battery is transported by sea. In battery module or assembly manufacturing, the lugs (note: lugs are the metal conductors that lead the positive and negative electrodes from the cell) are weakly welded to the cell or have no weld strength. Contamination on the surface of the part can lead to lower conductivity of the welded joint, which ultimately limits the overall performance of the cell pack.
Therefore, it is necessary to remove contaminants from the welded joints before welding, and at the same time, part damage and dangerous debris should be avoided, and the laser cleaning method is born.
Surface cleaning of the anode and cathode ensures high quality welds
The performance of a cell is greatly dependent on the quality of the connection between the cell and the lugs. Therefore, in order to improve the performance of the link, various welding methods are often used, such as laser welding, resistance welding, MicroTIG welding, and ultrasonic metal welding. However, the quality of the welded joint also depends on the cleanliness of the part. Contaminants on the positive and negative surfaces include grease, oil, corrosion inhibitors and other compounds from the process. These contaminants can cause problems such as poor fusion, cracks and porosity at the weld joint. The solution is to clean the surface before soldering.
- What methods are used to clean the battery surface?
There are two main methods used to clean the battery surface: dielectric blast cleaning (sandblasting or dry ice blast cleaning) and laser cleaning.
Dielectric blast cleaning is the use of abrasives directly tear off the surface contaminants. While the process is effective, it can also result in some micro-grooves that can affect the solder strength and appearance of the finished product. When used correctly, laser cleaning will not damage the surface. It is this ability to clean the surface without damaging it that makes laser cleaning effective in improving the entire welding process.
- What is laser cleaning
By cleaning the surface of the cell anode and cathode, it provides a pristine and repeatable surface quality, which greatly improves the quality and yield of the subsequent weld. Regardless of the welding process used, such as resistance welding, laser welding or ultrasonic metal welding, surface cleaning is significantly effective.
Laser cleaning machine is the process of removing surface material by focusing a laser onto the substrate. The amount of material removed depends on the laser intensity, pulse width and wavelength, as well as the material itself, i.e. the ability to absorb the laser and the energy required to break the chemical bonds in the area. The process is performed using either a pulsed nanosecond fiber laser or a continuous wave laser. The former is more widely used due to the high laser power density.
Compared to traditional media blasting methods such as sandblasting and dry ice blasting, laser cleaning has many benefits: fast cleaning, flexible operating methods and environmental requirements, safety, cost effectiveness and more environmentally friendly.
The battery industry is turning to laser cleaning of cell connection surfaces to improve weld quality and reduce costs.
The benefits of laser cleaning include
Laser cleaning of batteries is faster
Laser cleaning removes surface contaminants quickly and cleanly, reducing the need for subsequent processing. It has been reported that laser cleaning is 15 times faster than the traditional media blast cleaning process. This reduces cleaning time, greatly improves production beats and reduces manufacturing costs.
Using laser cleaning machine to clean the battery will be safer
Laser cleaning does not use abrasives. Abrasive blast cleaning operations can generate more dust and higher noise. For workers exposed to this environment, it can cause silicosis, lung cancer and breathing problems. Laser cleaning produces only very small amounts of dust, the material removed from the surface of the part. These small amounts of dust are easily collected by vacuuming devices. Laser cleaning operations are relatively quiet and do not require earplugs to suppress sound.
Using laser cleaning cell is more energy efficient and can reduce the cost of cleaning
The total cost of a laser cleaning system is significantly lower than the cost required for a media blasting system.
Various data prove that laser ablation cleaning surface, significantly improve the strength of the welding Increased battery life and durability.