SHINHOP laser

The reason lithium batteries can be widely used in electronic devices such as laptops, mobile phones, digital cameras, drones, PDAs, and in transportation like electric bicycles, electric cars, and buses is due to their advantages such as long cycle life, low self-discharge, high energy, no memory effect, and no pollution. They are the "driving force" of the future new energy industry.
Power batteries have a relatively large capacity and are mainly used in electric vehicles that consume a lot of power. They consist of multiple individual battery cells connected by nickel strips and a circuit control system, also known as battery PACK. Compared to batteries used in mobile phones and laptops, 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 complex, especially regarding some detailed welding issues. Without certain welding experience and good laser welding equipment, it is difficult to meet the standards of the battery welding industry, such as: explosion-proof valves (explosion-proof holes) need to be sealed and welded, laser welding of tabs, soft connection welding, spot welding of safety caps (battery cover caps), sealing welding of battery housings, and welding of modules and PACKs all require suitable battery welding machines for processing. Among them, power batteries are relatively difficult to process, and their welding materials are generally pure copper, stainless steel, aluminum, and aluminum alloy materials. The smaller the material resistance value, the lower the light absorption rate, and naturally, the laser energy is also less likely to be absorbed.
Below, SHINHOP battery laser welding engineers explain which fields of lithium batteries require the application of laser welding machines:
1. Top cover welding, requiring strong sealing:
2. Sealing nail welding:
3. Soft connection welding:
4. Module and PACK welding:
The series and parallel connections between power batteries are generally completed through the welding of connecting strips and individual battery cells. The positive and negative electrode materials are different, generally consisting of copper and aluminum. Due to the formation of brittle compounds after laser welding between copper and aluminum, which cannot meet usage requirements, ultrasonic welding is usually adopted. Copper and copper, as well as aluminum and aluminum, are generally welded using laser welding. At the same time, since both copper and aluminum conduct heat quickly and have a very high reflectivity to lasers, and the thickness of the connecting strips is relatively large, a higher power laser is required to achieve welding.
5. Laser welding of pole columns:
The materials used for battery tabs include pure aluminum strips, aluminum-nickel composite strips, pure nickel strips, and a small amount of copper strips. Generally, pulse laser welding machines can complete the welding. Later, with the emergence of the new generation of quasi-continuous laser welding machines, which have better beam quality and smaller weld spots, they effectively solve the welding difficulties of high aluminum strips, copper strips, and battery tabs with widths below 1.5mm. Therefore, their application is becoming increasingly widespread, and the number of users is growing.
6. Explosion-proof valve welding:
The battery explosion-proof valve is a thin-walled valve body on the battery sealing post. Its function is to automatically rupture when the internal pressure of the battery exceeds its safety value, preventing the battery from suddenly exploding and causing danger.
The design structure of the explosion-proof valve is quite clever and requires a high level of laser welding technology. In the past, pulse laser welding machines were often used for spot welding, gradually connecting through overlapping weld points to achieve sealing. However, this naturally results in lower welding efficiency and poorer sealing. Later, many battery manufacturers began using SHINHOP battery continuous laser welding machines for welding, thus solving the quality issues or safety hazards of welding, and improving the welding speed and product qualification rate of battery explosion-proof valves, making it a "magic tool" for battery welding.
7. Battery tab welding:
There are three materials used for producing battery tabs: aluminum for the positive electrode, and nickel or nickel-plated copper for the negative electrode. From the perspective of material types, the negative electrode is the most difficult to weld. Generally, laser welding machine manufacturers do not have this technology or equipment. In the welding process of power batteries, it is necessary to weld the battery tabs to the pole columns, and in the welding of secondary batteries, it is necessary to weld them to another aluminum safety valve. During the welding process, it is essential to ensure a reliable connection between the tabs and the pole columns, and to ensure that the weld seam is smooth and aesthetically pleasing. Currently, the equipment used for battery tab welding mainly consists of battery laser welding equipment produced by SHINHOP, which has a high market share.
8. Shell sealing welding, cover plate welding:
The shells of power batteries are mostly made of aluminum alloy materials, and some are made of stainless steel. Those made of aluminum alloy are generally 3003 aluminum alloy, although pure aluminum materials are also used. In terms of laser welding effects, stainless steel laser welding is excellent, whether it is pulse welding or continuous welding, the welding quality is outstanding.
Aluminum materials are different and require certain welding skills and equipment performance for specific processing. Generally, continuous laser welding machines are required for welding. Except for some pure aluminum and 3 series aluminum alloys that can use pulse welding, continuous laser welding is needed to solve welding issues. Regarding shell thickness, we need to choose a laser with a certain power. From the perspective of industry application, for aluminum shells below 1MM, a single-mode laser within 1000W can be used, while for those above 1MM, a 1KW single-mode or multi-mode fiber laser is needed as the energy supply source.
The above discusses larger batteries. For small capacity battery shells, thinner aluminum shells are used, generally with a thickness of around 0.25MM. Some also use steel shell materials, such as 18650 batteries. Due to their small size and thin shell thickness, low-power lasers are used for welding. However, if continuous lasers are used for welding, the speed can be increased by at least 8 times, and the appearance and sealing quality will be better. Therefore, if battery manufacturers have relatively loose capital and users pursuing quality can choose SHINHOP battery continuous laser welding machines as their primary welding equipment.
New characteristics of laser welding lithium batteries:
From the manufacturing of lithium battery cells to the assembly of battery PACKs, welding is a very important manufacturing process. The conductivity, strength, airtightness, metal fatigue, and corrosion resistance of lithium batteries are typical quality evaluation standards for battery welding. The choice of welding methods and processes will directly affect the cost, quality, safety, and consistency of the batteries. Laser welding, with its advantages of safety, reliability, precision, and environmental protection, has become the preferred solution for many welding tasks.
Advantages of laser welding machines specifically for batteries:
1. Laser welding is a fusion manufacturing process that integrates raw materials such as positive and negative electrode materials, separators, and electrolytes into a whole. The welded battery cells or PACK modules can be directly used in the automotive field.
2. The proportion of ordinary battery raw materials in costs is continuously increasing, and they are purchased in bulk by the ton. Laser welding equipment essentially allows for one-time procurement of raw materials, saving costs.
3. Laser welding can greatly improve the safety, reliability, and service life of automotive power batteries, with high welding quality and automation levels.
4. Laser welding has high energy density, small welding deformation, and a small heat-affected zone, which can effectively improve the precision of the workpiece. The weld seams are smooth, free of impurities, uniform, dense, and do not require additional polishing work.
5. Laser welding can be precisely controlled, with a small focused spot and high-precision positioning. It is easy to achieve automation with robotic arms, and the equipment is stable and easy to operate, improving welding efficiency, reducing labor hours, and lowering costs.
6. When laser welding thin sheets or fine diameter wires, it is not as easily affected by re-melting as arc welding.
Analysis of the development status of the lithium battery new energy industry:
1. Development status of the new energy lithium battery industry:
After more than ten years of development, China's lithium battery industry has established a complete industrial chain that includes lithium ore mining, material supply, cell and PACK production, and battery recycling. Driven by downstream market demand, the lithium battery industry has maintained rapid growth in production scale, increasing from 17.2 GWh in 2012 to 88.7 GWh in 2017, a fourfold increase in five years.
Electric vehicles (mainly new energy vehicles), 3C digital products, and the energy storage industry are the three major driving forces for the development of the lithium battery industry. In 2016, the demand for new energy vehicles exceeded 3C digital products at 30.8 GWh, becoming the largest consumer market for lithium batteries. By 2017, the production of power batteries increased to 44.5 GWh. The energy storage battery has huge development potential, but due to technical and policy reasons, it is still in the market introduction stage, lagging behind power batteries. In the future, as technology matures, the energy storage market will also become another driving force for lithium battery consumption.
2. Development trends of new energy vehicles related to the power battery industry:
With the increasing prominence of the global energy crisis and environmental pollution issues, the development of energy-saving and environmentally friendly industries has been highly valued, leading to explosive growth in new energy vehicles. Production increased from 12,600 units in 2012 to 794,000 units in 2017, with a compound annual growth rate of 99.4%. In 2017, production and sales were 794,000 and 777,000 units, respectively, representing year-on-year increases of 53.6% and 53.3%, with production and sales growth rates increasing by 2.1 and 0.3 percentage points, respectively. In 2017, the market share of new energy vehicles was 2.7%, an increase of 0.9 percentage points from the previous year. China has surpassed the United States to become the world's largest new energy vehicle market, maintaining the highest production and sales for three consecutive years.
As the core component of new energy vehicles, power batteries closely follow the overall market trend of new energy vehicles, and the power battery market is also showing explosive growth. A large influx of capital has driven a significant increase in power battery production.
In 2017, the production of power batteries for automobiles in China reached 44.5 GWh, a year-on-year increase of 45%. OFweek predicts that in the next four years, the demand for power batteries will maintain a compound annual growth rate of over 40%, and by 2020, the demand for power batteries in China's new energy vehicles will exceed 120 GWh.
Lithium batteries, power battery packs, soft-pack batteries, and other battery products are the basic guarantee for the development of the new energy industry and are the trend for the future development of modern life and industrial production, possessing huge market space. Therefore, to achieve matching production equipment, various battery laser welding machines have begun to emerge like mushrooms after rain. Various power battery pack welding machines, specialized battery cap laser welding machines, and ear laser welding machines have appeared in various new energy manufacturers. Their specialized equipment ensures the integrity and safety of battery quality. SHINHOP Laser entered the battery industry relatively early, and its professional technical equipment has been well tested in practical applications in new energy enterprises. Over more than ten years, it has undergone good technological upgrades and improvements, becoming one of the most widely used professional battery accessory laser welding equipment in domestic battery manufacturers.