The reason why lithium batteries can be widely used in laptops, mobile phones, digital cameras, drones, PDAs and other electronic equipment, as well as electric bicycles, electric cars, buses, etc. for transportation is due to their long cycle life. It has the advantages of long life, small natural discharge, high energy, no memory and pollution, etc. It is the "driving force" of the new energy industry in the future.

The power battery has a relatively large capacity. It is mainly used in vehicles that consume large amounts of power such as cars. It is composed of multiple individual battery units through nickel sheet welding and a line control system. It is also called a battery PACK. Compared with mobile phones, it is for notebook batteries, their energy storage capacity is larger and the output power is naturally higher. The production process of lithium-ion batteries or battery packs is relatively long, especially some detailed welding problems. There is no certain welding experience and good laser Welding equipment is difficult to meet the battery welding industry standards, such as: explosion-proof valve (explosion hole) requires sealing welding, tab laser welding, soft connection welding, safety helmet spot welding (battery cap), battery shell sealing welding, mold Pack and PACK welding need to be welded by a suitable battery welding machine. Power batteries are relatively difficult to process. The welding materials are generally pure copper, stainless steel, aluminum and aluminum alloy materials. The smaller the resistance value of the material, the better The smaller the laser absorption rate, the less likely it is that the laser energy will be absorbed.

Below, a SHINHOP battery laser welding engineer explains which areas of lithium batteries require laser welding machine applications:

1. Welding of the top cover requires strong sealing:

2. Sealing nails welding:

3. Soft connection welding:

4. Module and PACK welding:

The series and parallel connection between power batteries is generally completed by welding the connecting piece to the single battery. The materials of the positive and negative electrodes are different, generally copper and aluminum. Since copper and aluminum form a brittle compound after laser welding, they cannot to meet the usage requirements, in addition to ultrasonic welding, copper and copper; aluminum and aluminum are generally laser welded. At the same time, since both copper and aluminum conduct heat very quickly and have very high laser reflectivity, the thickness of the connecting piece is relatively large, so a higher-power laser is required to achieve welding.

5. Pole laser welding:

The materials used in battery pole strips include pure aluminum strips, aluminum-nickel composite strips, pure nickel strips and a small amount of copper strips. Generally, pulse laser welding machines can be used to complete the welding. Later, due to the emergence of a new generation of quasi-continuous laser welding machines, it’s the beam quality is better and the welding spots are smaller. It is a good solution to the welding problems of high-aluminum strips, copper strips and narrow-band battery pole strips with pole strip widths below 1.5mm. Therefore, its application is becoming more and more widespread, and the number of users is increasing. Come more and more.

6. Explosion-proof valve welding:

The battery explosion-proof valve is a thin-walled valve body on the battery sealing coupler. Its function is to automatically rupture when the internal pressure of the battery exceeds its safe value, preventing the battery from suddenly bursting and causing danger.

The design structure of the explosion-proof valve is relatively ingenious, and the technical level of the laser welding process is relatively high. In the past, pulse laser welding machines were often used for spot welding, and the sealing was achieved by slowly connecting the welding points through the overlap of the welding points. However, the welding efficiency was naturally relatively low. , the sealing performance is definitely poor, but later many battery manufacturers began to use the SHINHOP battery continuous laser welding machine for welding, thereby solving welding quality problems or safety hazards, and improving the welding speed and product qualification rate of battery explosion-proof valves. It can be called a battery welding artifact.

7. Battery tab welding:

There are three types of materials used to produce battery tabs. The positive electrode is made of aluminum, and the negative electrode is made of nickel material or copper-plated nickel material. In terms of material types, the negative electrode is the most difficult to weld. Generally, laser welding machine manufacturers do not have this technology or Equipment, during the welding process of power batteries, the battery tabs and poles need to be welded together, and during the welding of secondary batteries, they need to be welded together with another aluminum safety valve. During the welding process, the tabs need to be ensured Reliable connection with the pole, and the welding seam needs to be smooth and beautiful. Currently, the battery laser welding equipment produced by SHINHOP Laser is the main product used for battery tab welding, and its market share is quite high.