More and more attention has been paid to sustainable development, leading to increasing demand for electric vehicles. The main component of an electric vehicle is a lithium-ion battery. The battery is not only part of the power system, but it will also play a key role in achieving new types of connectivity and autonomous driving.
Covestro has extensive experience in packaging lithium-ion batteries for laptops and other electronic devices. The company has developed a variety of polycarbonate blends that can be used in both electronics and applications. In the automotive industry, it is used to manufacture electric vehicle battery modules, housing components, battery cell brackets, and crash cushioning devices. Such materials are strong, dimensionally stable, and lightweight, and even flame retardants can be added as required.
At the recent battery show in Stuttgart, Covestro demonstrated its latest innovations in thermoplastics and battery components, which provide good crash protection and use a pultrusion process Made of polyurethane.
Dr. Julian Marschweski, an expert in Covestro's electric mobility department, explained that the company's current focus is on research and development processes to enable large-scale production of complex plastic parts for batteries. Covestro's flame retardant polyurethane blends need to be processed into thin-walled pieces to allow the interior of the battery to accommodate as many cells as possible.
Currently, Covestro is working with adhesive manufacturer Henkel to use UV-activated Loctite adhesives to permanently bond plastic parts in high-voltage batteries. They are testing new adhesives on injection molded parts made of flame-retardant PC ABS (engineering plastic alloy) Bayblend FR3040 EV. The thickness of this new plastic is only one millimeter, which complies with the Underwriters Laboratories UL94 flammability class V-0, but when the ultraviolet wavelength reaches 380 nm or more, it has good permeability to ultraviolet radiation.
One of the ways to use this new plastic is to use it to permanently attach cylindrical batteries to surrounding cell holders. Loctite adhesives can be processed as a single-component system, and they can be UV lighted within 15 seconds Curing. Therefore, combining UV-permeable plastic with a fast-curing adhesive can shorten the cycle time required for large-scale production of battery modules and batteries.
Lithium-ion batteries also need to meet special safety requirements to ensure safety in the event of an impact. In response to this situation, Covestro has developed a complete concept using different materials to enable the battery module to be protected to the greatest extent. The bottom profile of the battery case is very stable. This type of material is made of glass fiber or carbon fiber made by continuous manufacturing process, and Baydur PUL's polyurethane matrix made by pultrusion process.
This type of material has the highest strength in the longitudinal direction, which can keep the shape of the battery module safe. Moreover, it has high production efficiency and low cost, and can be easily combined with other materials.