Increasing the sustainability of EVs with ultrasonics to save energy, materials and rejects.
The production of vehicles with internal combustion engines (ICEs) has undergone extensive optimisation over the years, while the mass production of EVs is still in its early stages. This presents captivating opportunities for companies to enhance both production sustainability and cost-effectiveness. One promising solution is the use of ultrasonic welding technology. When joining both plastic and metal applications, the process saves energy, scrap and raw materials, offering a promising link between sustainability and cost-effectiveness in the production of EVs.
SAVING ENERGY WITH ULTRASONICS
One of the most significant opportunities for energy savings lies in battery production. Traditionally, the sealing of pouch cells has been inefficient, often relying on thermal joining methods like heat sealing. However, these processes consume substantial amounts of energy and pose a risk of damaging the battery cell foils.
Based on experience from other industries, there is untapped potential here. Although ultrasonic sealing of pouch cells has not yet widely been implemented, it has successfully been used for sealing pouch packages in the food industry for may years. This process has demonstrated energy savings of up to 75% compared to conventional methods.
USING ENERGY ONLY WHERE IT IS NEEDED
The key to achieving energy savings lies in ultrasonic sealing. Unlike traditional methods, this technology does not rely on an external heat source. Instead, heat is generated internally within the materials through friction during the brief welding process, lasting only 100 to 200 milliseconds. This targeted approach ensures that energy is utilised only where necessary, eliminating any wastage between the welding tool and the application.
Another benefit is that the welding tools remain cool and ready for immediate use, eliminating the need for preheating, saving additional energy. Preliminary tests conducted in both the ultrasonic laboratory and production settings have confirmed that the experience gained from sealing pouch packaging can be effectively applied to the sealing of pouch cells. Given rising energy prices and rapidly growing demand for energy, savings become a major advantage for companies both ecologically and economically.
Alongside energy savings, reducing resource consumption plays a crucial role in enhancing the sustainability and cost-effectiveness of EV production. Ultrasonic welding facilitates a substantial reduction in resource consumption in two ways: the reduction of scrap rates, and the elimination of additional adhesives.
CONSISTENTLY LOW SCRAP RATES
As one of the most cost-intensive components of an EV, the battery is a particular focus when making production safer and more sustainable. With dwindling availability of rare earth materials and the costly recycling of used batteries, responsible handling of raw materials is critical.
Ultrasonic welding significantly reduces the scrap rate during battery production. The generator can gather valuable data during the process through direct contact between the welding tools and materials. This data enables the visualisation and optimisation of welding parameters such as force, energy, and amplitude. By recording up to 150 parameters per weld, it becomes possible to minimise industry-standard scrap rates from up to 20%, to a single-digit percentage.
NO NEED FOR ADDITIVES
Many plastic applications in EVs still rely on adhesives due to the relatively low investment costs of the technology. However, the chemicals present in adhesives can have adverse environmental effects during production and disposal. Adhesives often demand increased energy input, such as heating or drying, to ensure their efficacy. The utilisation of these chemicals not only effects the sustainability aspect but also contributes to ongoing cost factors. In recent years, the prices of raw materials have escalated, leading to a significant rise in costs associated with adhesive usage. Consequently, reducing reliance on such chemicals becomes imperative for maintaining a favourable sustainability balance and managing expenses.
Ultrasonic welding eliminates the need for additional joining agents to achieve safe and permanent connections between applications. By using ultrasonic vibrations, the reliance on adhesives and the associated energy requirements are avoided. Machines and production equipment that utilise adhesives require regular cleaning, resulting in downtime that decreases production efficiency. Ultrasonic welding not only offers a positive impact on the environmental balance sheet, but also a more streamlined and efficient production process.
SWITCHING TO SUSTAINABLE MATERIALS
The use of plastics in EVs is on the rise. Wherever feasible, there is a push to replace metal applications with plastic alternatives. This shift is primarily driven by the multiple advantages that weight reduction through plastics offers: improved energy efficiency, increased battery life, enhanced handling and manoeuvrability, and reduced manufacturing costs.
By choosing the right plastic, companies can make an important contribution to sustainable production. Recycled plastics made of polypropylene (PP), polyethylene terephthalate (PET), polyethylene (PE), ABS, PVC, and polystyrene, are particularly suitable. However, the utilisation of recycled plastics presents new challenges for joining processes. Each recycling process affects the quality of the material and subsequently, its ability to weld. Initial welding tests conducted with 100% pure recycled PA 6.6 have demonstrated comparable results to conventional plastics in terms of appearance, density and tensile strength. This indicates that recycled plastics can be a viable alternative for EV components.
COMBINING SUSTAINABILITY WITH EFFICIENCY
To meet the increasingly stringent goals in EV production, companies must focus on improving efficiency and sustainability simultaneously. Ultrasonic welding offers a safe and efficient process that can reduce energy consumption and scrap rates. It also enables the secure joining of more sustainable materials, including recycled plastics. These factors play a crucial role in reducing emissions and preserving critical resources. By embracing ultrasonic welding technology, companies can make strides toward achieving their sustainability goals while enhancing cost-effectiveness in the production of EVs.
Markus Haas is Global Head of Sales METALS at Herrmann Ultraschall.