Battery packs are essentially a collection of individual battery modules, which are composed by li-ion battery cells, that are arranged and connected to provide the energy required to power an electric vehicle. As one of the most critical components of the vehicle, the battery pack determines the performance, driving range and overall cost of the car.
A typical battery pack is composed by a great number of individual battery cells and modules, which can be connected in series, parallel, or a combination of both. In many, cases, these connections must be made between dissimilar metals.
Once the cells and modules have been connected, the whole battery pack is encased. The mechanical cases used to enclose the battery packs not only protect them, but function as structural elements in the vehicle.
Therefore, building battery packs generally involves two related processes: creating the electrical connections and mechanical cases that enclose the electrical elements.
EV Battery Packs - Challenges of High-Speed Production
Connections
Properly joined electrical connections ensure that the battery cells and modules work together as a unified energy storage system. They carry electrical current between the aforementioned elements, allowing for a coordinated charge and discharge.
The connections must be designed to handle the high currents and voltages generated during charging and discharging. The design must also consider resistance and heat buildup, which can cause inefficiencies and reduce the lifespan of the battery cells.
The main challenge when making these connections is that most of the time, the materials used are dissimilar or coated, which require special processing. Due to the high conductivity of these materials, it is also essential to have low spatter, to avoid potential short circuit reliability issues.
Fiber laser welding solutions for electrical connections in battery packs using dual-beam Adjustable Mode lasers and real-time laser weld measurement provide low-porosity and spatter-free welding of copper connections, as well as unmatched weld quality assurance, allowing for immediate rework of any deficient weld due to defects in the material quality, part handling or contamination. This rework can save whole battery modules.
Cases
Cases for battery packs are usually made of a rigid and durable material, such as aluminum, steel, or reinforced plastics, that can withstand damages due to impacts, vibration, moisture and other environmental factors, as well as being able to protect the cells and modules in the event of an impact. They also provide thermal insulation and help dissipate heat generated by the cells during charging and discharging.
Therefore, high integrity, high strength welds are a mandatory requirement. As with welding electrical connections, dual-beam Adjustable Mode lasers enable low-porosity welding of aluminum cases, as well as high-speed, on-the-fly case welding.
Whether you need to demonstrate laser processing feasibility with your parts, or just want to bounce design and implementation ideas about your e-mobility manufacturing processes off an experienced laser engineer, don't hesitate to contact us.
IPG is the world leader of fiber laser technology and experts in materials processing. We apply this expertise to our e-mobility solutions, with the sole purpose of offering manufacturers the most reliable, and highly productive tools through laser processing to obtain the best e-mobility application results.
Learn more about the entire scope of E-Mobility solutions that IPG offers here.
Relevant Resources
EV Battery Packs Solutions
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