Welding is a crucial process in the production of battery module, which directly affects the cost, quality, safety and consistency of the battery. With the progress of science and technology, laser welding, as an advanced new welding method, has been widely used in the manufacture of battery modules. This article will elaborate on the working principle of laser welding and its advantages in battery modules.
Ⅰ. Basic Principle of Laser Welding
Laser welding is through the optical system will focus the laser beam in a very small workpiece area, using its excellent directionality and high power density and other characteristics of processing. In a very short period of time, the laser beam makes the workpiece to form a highly concentrated energy heat source area, thus making the workpiece melt and form a solid welding point and weld to complete the welding task. Laser welding is mainly divided into heat conduction welding, deep welding, penetration welding and seam welding and other forms, each form has its own specific application scenarios and advantages.
Ⅱ. Application of Laser Welding
In the production of battery module, laser welding is mainly used in the packaging of the core, the welding of the pole lugs and battery pack (PACK) assembly and other links. These links on the welding precision, stability and reliability requirements are very high, and laser welding can meet these requirements.
Cell encapsulation:
Cell encapsulation is one of the key steps in battery module manufacturing. By precisely controlling the focusing point and energy density of the laser beam, laser welding can realize precise welding of the shell and cover of the battery cell. This type of welding not only has smooth weld seams without impurities, but also has small welding deformation and a small heat-affected zone, thus ensuring the sealing and safety of the battery cell.
Terminal Tab welding:
The terminal tab is the key part of the battery cell connecting with the external circuit. Laser welding can achieve high-speed, high-precision welding of the lugs, while avoiding the spatter generated during the welding process to the internal pollution of the battery cell. In addition, laser welding can also realize welding of complex trajectories such as S-shape and spiral shape, thus increasing the bonding area of the weld and strengthening the welding strength.
Battery Pack (PACK) Assembly:
In the assembly process of battery pack (PACK), laser welding is widely used in the connection between cells, as well as the connection between cells, protection circuits, shells and other components. The high precision and stability of laser welding ensures the firmness and reliability of the internal structure of the battery pack, thus improving the overall performance and service life of the battery pack.
Ⅲ.Advantages of laser welding
High precision: laser welding can achieve precise welding of tiny areas, weld width and depth controllability, thus ensuring the precision and consistency of welding.
High efficiency: laser welding speed, heat-affected zone is small, can significantly improve production efficiency and reduce production costs.
High quality: laser welding welds are smooth, free of impurities, uniform and dense, and do not require additional grinding work, thus ensuring the quality of the weld.
Wide applicability: laser welding can weld a variety of materials, including steel, aluminium, copper, nickel, etc., thus meeting the welding needs between different materials in the battery module.
High degree of automation: laser welding is easy to integrate with automated equipment such as robotic arms to achieve automated production, improving production efficiency and stability.
Ⅳ. conclusion
In summary, laser welding plays an important role in battery module manufacturing. Its high precision, high efficiency, high quality and wide applicability and other characteristics make laser welding an indispensable process in the manufacture of battery modules. With the continuous development and progress of science and technology, laser welding technology will be more widely used and promoted in the field of battery module manufacturing.
