Laser Technology for Lithium ion Battery Welding

What is a battery ?

A battery Cell is basically a kind of storage device which stores energy in chemical form. When required, this chemical energy is converted to electrical energy.

• Batteries have applications in various industries and fields. They are used in house appliances, medical devices, measuring and other engineering instruments, motors, etc.
• Nowadays, due to the growing popularity of Electric Vehicles, the demand for batteries is increasing.
• Electric vehicles require a lot of energy to run. So, to power electric vehicles, a lot of batteries are stacked together. This is called modules. Many such modules together form a pack.
• For optimum output,  many battery packs/stacks  are connected in parallel combinations. Numerous batteries are stacked together, and connected using a thin/thick  sheet called bus bars. The bus bar is welded on the contact point of the terminal.

Use of Laser technology for Lithium ion Battery welding:

• One crucial parameter in battery welding is the thickness of the busbar and the terminal. Terminals are typically made up of nickel plated steel, with thickness of around 0.3 mm, whereas busbars are made of Copper, Brass or Aluminum.
• Generally, the thickness of the busbar is 60 % to that of the terminal for cell type battery connection and slightly thicker for prismatic batteries.
• For proper welding, the weld must penetrate completely through the bus bar, should only go halfway through the terminal, and not completely penetrate through it.
• If penetration is not enough, the weld will not be strong enough and if penetration is deeper than required, the chemicals inside the battery may be triggered leading to burning or explosion.
• While welding these connections, the total heat input should not exceed the damage threshold of the battery cells. This requires a very concentrated and fast source of welding.
• Laser technology helps to have precise control over penetration, heat input and also gives high weld strength. That is one of the reasons why Laser technology is ideal for battery welding.

Some other advantages of Laser technology in battery welding are:

• Flexible, repeatable process
• Welding of dissimilar materials like copper to aluminum is possible
• Faster, scalable than other processes
• Higher weld strength
• Ideal for Welding of highly conductive metal
• High precision

Any query? Feel free to contact us.