Optimizing the Welding Process in the Battery Industry | Case Study

A leading manufacturer of battery components faced a complex technological challenge related to welding tin-coated copper to nickel-plated copper. Due to the low boiling point of tin, the initial welding process resulted in high porosity and unstable joint quality.

An additional constraint was the presence of plastic insulating components located very close to the weld zone, which could not be exposed to excessive heat.

The customer’s objective was to achieve a stable, repeatable process suitable for high-volume serial production.

We developed a comprehensive process solution for joining tin-coated copper with nickel-plated copper, combining process development, equipment selection, parameter optimization and dedicated fixturing. The project drew on our expertise in laser welding automation, with the objective of achieving a stable and repeatable joining process suitable for high-volume serial production.

The solution included:

• optimization of laser welding parameters, including laser power and welding time, to reduce porosity and achieve stable joint quality,
• design of a dedicated clamping system to ensure consistent positioning, joint stability and repeatability,
• implementation of an air-blow system to improve heat management and protect temperature-sensitive components located close to the welding area,
• preparation of the complete process for transfer to serial production.

A critical part of moving laser welding from trials to serial production was ensuring that the selected parameters and tooling could deliver consistent results under actual production conditions rather than only during individual laboratory tests. For this reason, process development focused not only on producing a sound weld, but also on repeatability, thermal control and robustness against production-related variation.

This approach also addressed the broader requirements of laser-welding process window and quality control, where the objective is to establish operating conditions that remain stable despite natural variations in materials, component positioning and process conditions. Careful parameter selection and dedicated clamping helped create a reliable basis for maintaining weld quality in serial manufacturing.

The project is directly relevant to battery module and pack automation, where laser joining must combine high electrical and mechanical performance with precise heat management, repeatability and protection of nearby temperature-sensitive components.

A similar early-stage engineering approach is presented in our pouch-cell design-for-automation case study, where laser welding trials and dedicated clamping were used to evaluate challenging copper-to-aluminium connections and influence the battery module design before automation was implemented.

Extensive testing and process validation confirmed:

• Significant reduction of weld porosity
• Controlled heat input, preventing damage to adjacent plastic components
• Stable and repeatable weld quality suitable for automated production

The optimized process met all quality and production requirements and was successfully transferred to serial manufacturing.

• Reduced production costs through minimized scrap and material losses
• Increased productivity – up to 4 million joints per year without additional downtime
• Improved joint quality, ensuring high mechanical strength and electrical conductivity
• Protection of sensitive components thanks to precise thermal control
• Fast transition to mass production

A combination of deep process expertise and dedicated engineering allowed us to transform a demanding material combination into a robust, production-ready welding process, supporting the customer’s long-term scalability.