Laser welding is widely used in the new energy lithium battery industry

Laser welding has always been an indispensable process in the lithium battery manufacturing process. From stainless steel shells to aluminum shells to polymers, laser welding is widely used. With the continuous development of the industry, higher requirements are put forward for the efficiency and quality of laser welding, and the use of optical fiber transmission laser welding is started. Due to the flexible connection between the welding machine host and the focusing head, this method is easier to match with the assembly line, Realize full automation. The appearance and performance of welding have also been significantly improved.


Lithium-ion batteries are widely used in various electronic devices (such as mobile phones, notebook computers, PDAs, digital cameras, digital video cameras, etc.) because of their high specific energy, long cycle life, low self-discharge, no memory effect, and no pollution. As well as transportation tools (patrol cars, electric bicycles, electric vehicles, etc.), it has become a high-tech industry supported by my country's energy sector.


Power battery refers to the battery used in electric vehicles. Compared with small-capacity batteries (such as mobile phones, laptop batteries, etc.), it has larger capacity and output power and can be used in electric vehicle driving power and large mobile power applications.


Secondary battery. There are many manufacturing processes for lithium-ion batteries or battery packs, and there are many processes, such as explosion-proof valve sealing welding, tab welding, soft connection welding, safety helmet spot welding, battery shell sealing welding, module and PACK welding. Take the laser welding machine as the process. The materials used for welding of power batteries are mainly pure copper (chemical formula Cu), aluminum (Al), aluminum alloy, and stainless steel.


The laser welding machine has the characteristics of high positioning accuracy, simple operation, CNC programming or teaching mode, simple and easy to understand, high welding depth ratio, high speed, flat, beautiful, and small width of the weld, no need to handle after welding, and high weld quality. The whole machine has a split design, modular structure, and quick fixture replacement. The equipment has high utilization rate and can weld a variety of products. It is suitable for combined applications in various industries and can be used for assembly line operations to improve quality and efficiency. The three-dimensional workbench and fully customized fixture can be controlled by industrial computer or PLC, and can provide a variety of solutions for the needs of different industries.


The following is the process application of laser welding in the lithium battery industry summarized by Huiyao Laser for everyone:

1. Welding of battery explosion-proof valve

The explosion-proof valve of the battery is a thin-walled valve body on the battery sealing plate. When the internal pressure of the battery exceeds the specified value, the valve body of the explosion-proof valve ruptures to prevent the battery from bursting. The safety valve (function: the control pressure does not exceed the specified value) has an ingenious structure. This process has extremely strict requirements on the laser welding process. Before the continuous (Continuity) laser welding, the battery explosion-proof valve was welded by pulse laser welding. The welding point and the welding point were overlapped and covered (Cover) to achieve continuous sealing welding, but the welding efficiency was low and the airtightness Relatively poor. Continuous laser welding can achieve high-speed and high-quality welding, and welding stability, welding efficiency and yield can be guaranteed.


2. Welding of battery tabs

The tabs are usually divided into three materials. The positive electrode of the battery uses aluminum (Al) material, and the negative electrode uses nickel (Ni) material or copper-plated nickel (Ni-Cu) material. In the manufacturing process of power batteries, one of the steps is to weld the battery tabs and poles together. In the production of the secondary battery, it needs to be welded with another aluminum safety valve. Welding must not only ensure the reliable connection between the tab and the pole, but also requires a smooth and beautiful weld.


3. Spot welding of battery poles

The materials used for the battery poles include pure aluminum tape, nickel (Ni) tape, aluminum-nickel composite tape, and a small amount of copper tape. The welding of battery electrode strips generally uses pulse welding machines. With the emergence of IPG's QCW quasi-continuous laser, it has also been widely used in battery electrode strip welding. At the same time, due to its good beam quality, the welding spot can be small, It has unique advantages in dealing with the welding of high-reflectivity aluminum strip, copper strip and narrow-band battery pole strip (the pole strip width is less than 1.5mm) (explanation: it can overwhelm the other side's advantageous situation).


4. The power battery shell and the cover plate are sealed and welded

The shell materials of power batteries include aluminum (Al) alloy and stainless steel (stainless acid-resistant steel). Among them, aluminum alloy is mostly used, generally 3003 aluminum alloy, and a few use pure aluminum. Stainless steel is a laser weldable material, especially 304 stainless steel, whether it is pulsed or continuous laser can obtain welds with good appearance and performance.


The welding performance of laser welding of aluminum and aluminum alloys (melting point 660°C) varies slightly depending on the welding method used. Except for pure aluminum and 3 series aluminum alloys, there is no problem in pulse welding and continuous welding. Other series of aluminum alloys choose continuous laser welding to reduce crack sensitivity. At the same time, according to the thickness of the power battery shell, select a laser with appropriate power (referring to how much work the object does in a unit time). Generally, when the shell thickness is less than 1mm, single-mode lasers within 1000W can be considered, and the thickness is more than 1mm. Use single-mode or multi-mode lasers above 1000W.


Small-capacity lithium batteries often use relatively thin aluminum shells (thickness about 0.25mm), and 18650 and the like use steel shells. Due to the thickness of the shell, a lower power laser is generally used for welding such batteries. Using Continuity laser to weld thin-case lithium batteries, the efficiency can be increased by 5 to 10 times, and the appearance and sealing are better. Therefore, there is a trend to gradually replace pulsed lasers in this application field.

评论

发表评论

此博客中的热门博文

What should I do if the laser welding machine fails during welding?

图片
With the improvement of technical level, the current manufacturing method has changed from traditional contact processing to laser non-contact processing to improve welding efficiency and welding effect. However, in the actual use process, various problems will still be encountered that affect the welding effect. Below, Huiyao Xiaobian will briefly explain how to deal with cracks during welding with laser welding machines and how to deal with some common faults. ​​ 一.  Cracks appear during welding by laser welding machine ​​ 1. The flow rate of the shielding gas is too large, which can be solved by reducing the flow rate of the shielding gas. ​​ 2. If the cooling speed of the workpiece is too fast, the temperature of the cooling water on the fixture should be adjusted to increase the water temperature. ​​ 3. The workpiece is not cleaned. In this case, the workpiece needs to be cleaned again. ​​ 4. If the matching gap between the workpieces is too large or there are burrs, the machining
阅读全文

Powering the Future: The Lithium Battery Module Assembly Line

图片
Lithium-ion batteries   have revolutionized the world of portable electronics and are increasingly being used in electric vehicles, energy storage systems, and renewable energy applications. The efficient and reliable production of lithium battery modules is critical to meet the growing demand for these advanced energy storage solutions. The lithium battery module assembly line plays a pivotal role in manufacturing high-quality battery modules. In this article, we will explore the significance of the   lithium battery module assembly line   and its role in powering the future. Efficient and Automated Manufacturing The lithium battery module assembly line is designed to streamline and automate the manufacturing process, ensuring efficient and consistent production of battery modules. Through a series of automated steps, including cell sorting, welding, stacking, and encapsulation, the assembly line enables a high-volume production capacity. The integration of advanced robotics, precisio
阅读全文

Simple Handheld laser marking machine

图片
Simple Handheld laser marking machine Handheld Fiber Laser Marking Machine  comes standard with a movable laser head for marking of parts in any direction and a 2D worktable for micro adjustment during the marking process. Its control button and worktable are set on the cover of the cabinet to save space. simple Handheld laser marking machine, The machine is suitable for large workpiece and long-distance marking.The mark is clear, beautiful, and never disappears. Laser Marking Machine   Features : Simple Handheld laser marking machine , Movable laser head: a wider range of work, not limited to a fixed working position; Wide application: handle both metal and non-metal materials; Stand out performance: consistent marking quality with high speed (up to 7000mm/s); 2-3 times higher than traditional marking; Long Lifetime: advanced laser generator, more than 100, 000h; Low consumption: Electro-optic conversion rate up to 30%, power consumption lowered by 3-10 times compared with YAG laser;
阅读全文