Should You Laser-Weld Lithium-Ion Batteries?

by Clarence Oxford
Los Angeles CA (SPX) Nov 13, 2025
Laser welding is a fusion welding process that involves the use of a focused laser beam to melt and join multiple materials together. This form of tech is now used across various industries to join metal, plastic, and other materials.

One such industry that laser welding has now found its way into is battery manufacturing. While battery manufacturers rely on resistance spot welding and ultrasonic welding, laser welding has also proved valuable for a range of reasons. Below, you can learn how lithium-ion batteries are made and why laser welding is a great technology to utilize during their creation.

How Are Lithium-Ion Batteries Made?

The manufacturing of lithium-ion batteries is a multi-step process consisting of electrode manufacturing, cell assembly, and cell finishing.

1. Electrode Manufacturing

Active materials are mixed together with a binder to form a slurry. The slurry is coated onto foil current collectors and dried to remove solvents. The resultant dried electrode sheets are pressed to achieve the right thickness and density before being slit into electrode widths for battery cells.

2. Cell Assembly

During the cell assembly process, the sheets are layered with a polymer separator to stop them from short-circuiting. The layered sheets are then stacked into a flat shape for a pouch cell or wound into a spiral for a cylindrical shell.

Finally, tabs are welded to each end, and then collectors are welded to the tabs to be connected to battery terminals. This process ends with the electrode stack being put into a case or cell housing.

3. Cell Finishing

A lithium salt solution in an organic solvent, known as the electrolyte filling, is injected into the cell before the cell is sealed to stop it from leaking. The battery will then be charged and discharged to activate the materials.

Testing is the final step, with the cells being stored for a long time to allow the chemical reactions to stabilize. All resultant lithium-ion batteries undergo rigorous tests to ensure performance and safety before shipment.

More Precision and Control

Precision is a crucial aspect of the lithium-ion battery manufacturing process. Without precision, batteries may not function properly or pose a hazard. Because lasers offer pinpoint precision, they can be the ideal form of tech to join the tiny, intricate parts of batteries without damaging them. Lasers also have an incredibly concentrated heat source, which means the chance of heat damage to adjacent parts can be low.

Better Strength and Reliability

Batteries need to be strong to be reliable in the equipment and transportation they will be installed in, like tools and vacuum cleaners. Fortunately, laser welds have high pull strength. This enhances the overall strength and safety of the battery pack.

A Fast Process

The more batteries a company can produce in a day, the higher its profit margins are. That's why the technology they use to produce batteries must be efficient. Laser welding machines are. Laser welding is a fast process that can increase overall manufacturing speeds, leading to high-volume production.

Clean Production

Laser welding is a clean process because the concentrated energy of the laser welder vaporizes surface contaminants, like rust, oil, and grease. No residue is left on the surface, resulting in a clean finish and a high-quality weld.

Laser welding is also non-contact and doesn't involve any abrasive media or chemical agents. This means that no impurities are introduced. As most manufacturers know, the less waste they produce, the more environmentally friendly their business can be.

Reduced Mechanical Wear

Most businesses factor mechanical wear into their budgets. They know they will eventually need to replace parts and equipment. Laser machines are no exception. However, because lasers provide a no-contact welding method, there is no mechanical wear on the welding equipment itself. This ultimately reduces downtime and maintenance costs.

Material flexibility

Whether you're manufacturing batteries for a powerbank, a motorcycle, or something else, they will always have a range of materials that need to be welded. Traditional welding machines won't always be suitable for all materials.

However, laser machines weld a range of materials used in battery manufacturing, such as stainless steel, copper, nickel, and aluminum. This versatility enables manufacturers to use one tool for multiple processes, rather than having to swap to different machines.

Laser welding is becoming more commonplace in a range of industries, including lithium-ion battery manufacturing. If your business hasn't yet explored it as an alternative to resistance welding, now might be the right time to consider it. You might be surprised by its range of benefits, like speed, reliability, precision, and cleanliness.