Covestro develops material expertise for future mobility

Covestro has many years of experience with covering lithium-ion batteries for laptops and other electronic devices and has developed various polycarbonate blends for this purpose.

A current cooperation between Covestro and the adhesive manufacturer Henkel involves permanently bonding plastic parts in high-voltage batteries with the help of UV-activated Loctite adhesives.

Together the partners are testing this on injection-moulded parts made of the flame-retardant PC+ABS blend Bayblend FR3040 EV. At a thickness of one millimetre, the plastic already meets’ category V-0 of the Underwriters Laboratories’ UL94 flammability rating but shows good permeability for UV radiation in the wavelength range above 380 nanometers.

One possible application could be the permanent bond of cylindrical battery cells with the surrounding cell holder. The Loctite adhesives are processed as a single-component system and harden under UV light within less than 15 seconds.

Therefore, the combination of UV-permeable plastic and fast-curing adhesive enables the short cycle times that are required for the mass production of battery modules and battery packs.

The materials are also well suited for manufacturing modules, housing parts, cell holders and crash absorbers for electric car batteries.

Dr. Julian Marschweski, expert for electromobility at Covestro, said: “A current focus of our activities is the development of processes for the efficient mass production of complex plastic parts for batteries. In order to accommodate as many cells as possible in the battery’s interior, our flame-retardant polycarbonate blends must be processed into especially thin-walled parts.”