Application of laser welding in power battery
The battery cell is the smallest unit in the electric vehicle power battery system and is also the electrical energy storage unit, composed of a positive electrode , a negative electrode , and a non-aqueous liquid electrolyte.
Multiple cells are combined in series and parallel to form a battery module, which then forms the entire battery pack.
Depending on the shape and packaging materials, there are three common types of battery cells: cylindrical batteries, prismatic batteries and soft pack batteries. Among them, the main difference between prismatic batteries and soft-pack batteries is the difference in packaging materials. Square batteries are packaged in hard shells, while soft-pack batteries use flexible aluminum-plastic film.
Power battery CELL laser welding includes intermediate process and back-end process
Middle process: This stage includes several key steps in the battery manufacturing process, as follows：
- Tab welding
- Spot welding of pole straps
- Pre-welding of battery cells into the case
- Sealing welding of the top cover of the casing
- Liquid injection port sealing and welding
Post-processing: This stage mainly involves the final assembly and packaging of the finished battery, as follows:
- Connecting piece welding
- Explosion-proof valve welding
Difficulties in laser welding of power battery pack
- Material properties：most battery cases are made of aluminum alloys, which are highly reflective of laser light, making welding more difficult
- Porosity problem：during the laser welding process, due to the fast cooling rate, hydrogen pores are easily generated, and these pores may affect the strength and quality of the weld
- Hot cracks：as a typical eutectic alloy, aluminum alloys are prone to hot cracks during the welding process, including weld crystal cracks and HAZ liquefaction cracks, which will adversely affect the performance of the welded joints
- Spatter problem：Spatter will affect the welding quality, and its factors include the cleanliness and purity of the material and the stability of the laser
Newlaz solutions
As the industry’s leading provider of intelligent laser welding solutions in subdivided fields, NewFA3, a brazing wire feed welding joint independently developed by Newlaz, has high-precision welding seam tracking and automatic focus compensation functions, which can realize power battery: ide plate welding, module welding, Busbar welding, cover plate welding, pole welding, etc.
- laser brazing
- Filler wire welding
- Laser aluminum welding
Features：
- Contact real-time weld tracking
- It has a spot compensation function to keep the spot size at the TCP stable.
- Suitable for laser brazing and fusion welding
- Equipped with human-machine interface to facilitate parameter setting, fault diagnosis and status monitoring
- Modular design, easy to expand
- Y-direction deflection of plus or minus 90 degrees, adaptable to a variety of processing conditions
The laser flight welding system is a non-contact robotic laser welding technology that eliminates non-production movement time and provides higher welding speeds compared to traditional laser welding. The laser flight welding system launched by Newlaz can provide a variety of welding process modes (circular, straight-shaped, Z-shaped, infinite-shaped, 8-shaped, spiral spot welding and other special-shaped welding processes) to maximize welding efficiency.
Features：
- quickly import welding patterns, customize welding patterns, and infinitely expand welding shapes
- On-the-fly welding function
- Position and power compensation function
- Offline control function
- Compatible with a variety of lasers
- Configure focus indicator
