The data shows that in 2021, China’s new energy vehicle sales reached 3.521 million, a year-on-year increase of 157.5%. The installed capacity of power batteries reached 154.5GWh, a year-on-year increase of 142.8%.

Power battery laser processing includes cutting, cleaning, welding and marking. These laser processes account for 15% to 20% of the power battery investment, while welding accounts for 5% to 15%. From 2021 to 2025, the new demand for laser welding equipment in China’s power battery field is increased from 5.6 to 22.1 billion yuan, and the CAGR from 2021 to 2025 is 41%.

Power Battery Laser Welding Difficulties

①At present, the main problems of laser welding in power batteries are welding defects such as air holes, cracks, poor forming, and blast holes. These defects lead to a decrease in the strength of the battery pack, a decrease in sealing and conductivity, and cause a series of safety problems such as battery explosion, liquid leakage and heat generation. In response to these problems, a large number of manufacturers focus on process optimization, and effectively reduce defects through technical improvement.

②On the basis of process optimization, the characteristics of the laser light source also have a certain impact on the welding quality of the power battery. Beam characteristics such as laser pulse waveform, spot radius, beam path, and laser wavelength have a significant impact on welding quality, and can further eliminate welding defects.

Since 2015, Optizone has mass-produced the kilowatt-level fiber optical cable, also known as the laser output head (QBH), and has been recognized by customers in the industry for its advantages such as stable performance. In response to these problems of power battery laser welding, the QBH produced by Optizone has improved fusion splicing technology, laser coaxial technology, 3D spot technology and other technologies. As a result, defects such as air holes, cracks, poor forming, and blast holes can be effectively reduced during laser welding of power batteries.

①Fusion Splicing Technology

The fusion splicing of large diameter quartz end caps and optical fibers is one of the key technologies for the development of high power fiber optical cable components.

The high-efficiency and high-reliability fusion between the quartz end cap and the optical fiber head is realized through the special welding technology. The fusion joint is cleaner. The high-power laser is prevented from damaging the fusion joint, and the power bearing capacity of the fiber optical cable is enhanced.

②Laser Coaxial Technology

When the product is actually used, if the deviation angle between the laser direction and the axis of the optical path is too large, part of the output laser will be irradiated on the nozzle, which will cause the temperature rise of the nozzle to be too large. In addition, it affects the output laser beam quality and power. Optizone QBH products strictly control the precision of mechanical parts and optical parts, so that the actual laser emission direction is infinitely close to the axis of the optical path, ensuring the accuracy of power battery welding.

③3D Spot Technology

Ring spot welding replaces the previous low-speed single-fiber welding, which can achieve faster welding speed and more uniform appearance.

Ring spot

The process window is wide, there is a wider window power adjustable space, and the compatibility is strong. The splash properties is low, which can well alleviate keyhole instability. It is multi-purpose, one set of ring spot device can be used as three devices. The single-open inner ring can be used as a traditional single-fiber laser, and the single-open outer ring can be used as a semiconductor laser, which can be used flexibly.

Flat top spot

Compared with the traditional Gaussian laser spot, the high-energy area of the flat-top spot is evenly distributed, and has a steeper edge transition, higher energy utilization efficiency, and better consistency of laser processing.

Optizone Water-cooling QBH (6000W)

Applications: 

Power Battery Welding

Features: 

Customized Wavelength

Customized Fiber (Ring fiber, double-clad fiber, triple-clad fiber, etc. cladding diameter: 125~1100μm)

Customized High Power (800~20000W)

Option to Choose Single or Double Head

Water-cooling

Product Superiority:

Choose a low hydroxyl quartz column

High-quality end-face coating

High ovality (0.98)

Stable beam directivity

Uniform and stable beam distribution

Universal window protection cap, matching IPG, Optoskand products

Can withstand 20000W forward power and 1000W reverse power, tail temperature switch (50±5 ℃) monitors device conditions

In addition, Optizone also has many products used in metal and non-metal welding, cutting, drilling, marking, rust removal, scribing and other scenarios, including fiber optical cables (SMA905, D80, QBH, QD, Q+), large beam collimator (QCS, LBC), air-cooled fiber end cap. For more details, welcome to inquire.

With the expansion of the power battery market and industry scale, the welding process optimization and technology upgrading at the front end will lay the foundation for the development of power battery laser welding and improve the efficiency of laser welding. Optizone Technology will continue to update and iterate, to provide better products and services for the manufacturing of power batteries, as well as efficient and comprehensive solutions.