Large-format plastic housings for high-voltage e-mobility batteries
LANXESS and Kautex Textron GmbH & Co. KG have been collaborating to research whether battery housings for electric vehicles can be designed and manufactured from technical thermoplastics.
They have developed a near-series technology demonstrator in a feasibility study. With a length and width of around 1,400mm each, the system is a technically sophisticated, large-format all-plastic housing part with a weight in the mid-double-digit kilogram range.
The goal of the project was to demonstrate the advantages of thermoplastics over metals in terms of weight and cost reduction, functional integration and electrical insulation behavior.
Felix Haas, Director Product Development at Kautex Textron, said: “As a first step, we have completely dispensed with the use of metallic reinforcement structures while proving we can commercially produce these complex large components.”
Dr Christopher Hoefs, Project Manager e-Powertrain at LANXESS, added: “Going forward, Kautex and LANXESS want to use the results of the co-operation to enter into development projects for series production with automotive manufacturers.”
The demonstrator was developed based on the battery housing of a C-segment electric vehicle. It consists of a housing tray with crash structure, a housing cover and an underrun (underbody) protection. The housing components can be produced in a single-stage Direct Long Fiber Thermoplastic (D-LFT) moulding process. LANXESS has optimised Durethan B24CMH2.0 as the material for the D-LFT moulding compound. Kautex Textron compounds the PA6 for the process with glass fibre rovings. The local reinforcement of the housing structure is carried out using continuous fiber-reinforced thermoplastic composites of the Tepex dynalite brand from LANXESS.
Today, housings for high-voltage batteries are primarily made of extruded steel or aluminium profiles. Complex structures made from strand press profiles require many secondary work steps such as welding, punching and riveting. In addition, the metallic components must be protected against corrosion in an additional process step by cathodic dip coating. Plastics, howver, can exploit design freedom, and the number of individual components of a battery housing can be greatly reduced.
Plastics also carry additional qualities including corrosion-resistance and electrical insulation. The low density of plastics and their potential for lightweight construction lead to significantly lighter housings.