Electric vehicle (EV) manufacturers are racing to bring new models to the market but face multiple challenges, such as meeting the demand for shorter charging times or reduced battery weight. Many challenges concerning performance and sustainability reside in the battery manufacturing process itself, so let’s consider some major ones and how to overcome them.
Major challenges in electric vehicle battery manufacturing
1. Fulfilling safety requirements
Temperature management is one of the major challenges. Battery cells must be operated within a specific temperature range to preserve performance and avoid overheating. For these reasons, a heat-conducting, gap-filling paste is applied. But the high-volume application of the paste can result in bubbles forming that damage thermal conductivity.
To protect the EV battery in the event of a collision, cell stacks can be reinforced with lateral braces. However, common joining techniques like spot welding are not suitable because they create heat and welding splatter that can harm the sensitive battery cells.
Ensuring operator safety during the production of EV batteries is critical because the cells and modules that make up the battery are electrically charged, with DC voltage levels ranging from a few hundred up to a thousand. Risk assessment needs to be carried out. Your operators must be trained in safe working practices for EV battery assembly and provided with the special tools needed while working on electrical batteries up to 1,000 V. (IEC 60900)
2. Safeguarding quality
The race to innovate in any industry can lead to lower levels of quality. Undetected defects produced during battery manufacturing lead to costly recalls for the EV industry. These include application defects in cell bonding, battery sealing, or the many different materials that need to be joined, such as high-strength steel and aluminum.
3. Rising costs
When you think about cost savings in high-volume battery production lines, every little bit helps. Think about reducing rework, rejects, and material waste. Especially in dispensing applications, there is a high potential for optimization.
4. EV batteries need to be optimized for safety, durability, and performance
The International Energy Agency’s Sustainable Development Scenario forecasts a global EV growth of 36% annually, reaching 245 million vehicles in 2030. That is over 30 times above today’s level. Rapid growth in EV demand presents a range of new challenges for vehicle manufacturers when it comes to production in terms of materials, battery systems, and joining technology due to the need for light-weighting, a critical factor in reducing CO2 emissions.
As the weight of batteries is considerable, automotive engineers are tasked with developing new techniques to make new electric cars as light as possible while improving range capacity. Alongside weight reduction, the various types of batteries used in automotive drivetrains need to be optimized for safety, durability, and performance.
Overcoming EV battery manufacturing challenges
Improvements to the weight, capacity, and charging times of EV batteries are needed to meet performance requirements and limit environmental impact. Getting the EV battery manufacturing process right the first time is a major concern.
1. Safety first
Safety starts with the raw materials for cell production. Machine vision solutions can be used to find defects in the separator film or the coating of the electrodes. If they are damaged, short circuits can occur.
Add a fire protection layer: If battery cells get inflamed, there is a risk that they will burn through the battery cover. A layer of fire-resistant material with the proper thickness applied to the lid keeps the fire contained for as long as possible.
Seal the battery tray and cover to keep humidity out of the battery and protect the driver from harmful gases. Use a high-precision application system with a bead inspection solution to prevent gaps, air bubbles, or material accumulations in the sealing that lead to weak points and leakage.
Working on live battery components requires special equipment to protect the operators from electric shock. We enable vehicle manufacturers to mitigate risk through a range of measures, including the development of fully insulated sockets and quick-change adapters, as well as insulated tool covers and slip-off protection for handheld electric assembly tools while working on electrical batteries up to 1,000 V (IEC 60900).
2. Never compromise on quality
EV battery manufacturing quality starts with the raw materials. Separator film/coating inspections can help catch defects in the material before further processing. Make sure you inspect every battery cell for surface damage at full in-line production speed and not impact productivity.
When working with manual tools, support your operator best to deliver the highest level of quality. Process control and bolt positioning help precisely position the tightening tool and tighten the right sequence.
When working with automated joining technologies, the solutions should offer additional quality assurance features: Flow drill fastening pre-hole detection and centering will ensure the perpendicularity of the joining element in the process. Self-price riveting will need preventive die inspection to catch any signs of wear. Dispensing systems should always come with bead inspection.
3. Keep an eye on costs
Gap filler applications need significant amounts of costly thermal compound. Application tests suggest material savings of up to 20% when you use a “smart adjusted” gap filler application with a system that measures the part, calculates the required material, adjusts the application, and controls the result.
Conventional pumps leave a considerable amount of material in the barrel. Make sure you use innovative systems that minimize the material left over in the barrel and purging efforts. This way, you can save up to a million euros per year and pump.
Rework is a huge cost driver, especially when it comes to manual tightening. You can significantly reduce rework when using tightening solutions with bolt positioning. Operator guidance reduces defects and scrap.
4. Sustainability comes with the technology
Choose self-pierce riveting over resistant spot welding: To join the battery tray, you can use different joining technologies, for example, spot welding or self-pierce riveting. Self-pierce riveting offers a clean, cold joining process and is more energy-efficient. If the average battery tray has 500 aluminum joints, using self-piercing rivets rather than resistant spot welding uses approximately 9.575 fewer kWh per tray, calculating out to a saving of 1,005 tons of CO2 per year on a volume of 150,000 trays.
Choose flow drill fastening magazine solution over blow feed: Many fasteners need to be processed at short cycle times in flow drill fastening. In a blow-feed standard system, you need compressed air to transport the fasteners through the tube. That means high energy consumption. A magazine solution can reduce 66% of the air consumption compared to a standard blow-feed system. This can save up to 50 metric tons of CO2 emissions yearly.
