LANXESS and Kautex collaborate to develop large-size all-plastic shell parts for EV high-voltage batteries
In order to study whether the battery shell of electric vehicles can be designed and manufactured with high-tech thermoplastics, specialty chemicals company LANXESS and Kautex, a subsidiary of Textron Group, have been cooperating for many years. In a feasibility study, joint development A technology demonstration sample close to mass production is produced. The length and width of the battery shell system are 1400 mm, respectively, and it is a large-sized all-plastic shell component with complex technology. The weight in kilograms is in the middle of the double-digit range.
The goal of the project is to prove the superiority of thermoplastics over metals in terms of weight reduction, cost reduction, functional integration and electrical insulation.
"As the first step, we have completely abandoned the use of metal reinforcement structures, and at the same time proved that we can produce these complex large parts commercially." Related personnel explained.
"In the next step, Kautex and LANXESS hope to use the results of this cooperation to participate in the mass production development projects of automakers." The relevant personnel added.
This technology demonstration device close to mass production has a length and width of approximately 1400 mm. The battery shell cover system is a large-scale all-plastic shell component with complex technology. The weight in kilograms is in the middle of the double digits. Within range
Short-cycle single-stage manufacturing process
The demonstration piece was developed on the basis of the battery shell cover of a C-segment electric vehicle, and consists of a shell tray with an anti-collision structure, a shell cover and a bottom shield. The battery shell assembly can be produced in a single-stage direct long fiber thermoplastic (D-LFT) molding process. For this reason, LANXESS has optimized the Durethan B24CMH2.0 material for D-LFT molding compounding. . Kautex uses glass fiber roving to blend this PA6 material from LANXESS for this process. The local reinforcement of the battery shell structure is achieved by using the continuous fiber reinforced thermoplastic composite material of the Tepex dynalite brand of LANXESS. "Compared with processing steel or aluminum, this process has a shorter cycle time and is therefore more economical." The relevant person explained.
No complicated metal forming, fewer production steps
The current high-voltage battery casing is mainly made of extruded steel or aluminum profiles. Depending on the type of vehicle, the length and width of the shell may exceed 2000mm or 1500mm, respectively. This size, combined with the number of components and the number of production and assembly steps, makes the cost of the metal shell very high. For example, a complex structure made of steel strand pressed profiles requires auxiliary processes such as welding, punching and riveting. In addition, an additional processing step is required to provide the necessary metal components through cathodic dip coating. Corrosion protection.
The demonstration piece consists of a shell tray with an anti-collision structure, a shell cover and a bottom shield
"On the other hand, it can also make full use of the design freedom of plastics. Through integrated functions such as fasteners and thermal management components, the number of individual components that constitute the battery shell can be significantly reduced, thereby simplifying assembly and logistics work and reducing production. Cost." Related personnel said. Plastics are also corrosion-resistant and have electrical insulation, which means that the risk of system short-circuits can be reduced. Not only that, the low density of plastics and its potential to achieve lightweight structures also make the battery casing significantly lighter, which is conducive to extending the operating range of electric vehicles.
High requirements for complex compounds.
The high-voltage battery casing must meet various strict technical requirements. For example, it must have sufficient rigidity and strength, and be able to absorb a large amount of energy in the event of a collision. This can be tested by mechanical impact test and compression test. In the event of a vehicle fire or battery heat loss, these shells must also be flame-retardant. Finally, these shells must be able to be integrated into the car structure.
"We will continue to cooperate to optimize the production process and structural design of these components. The goal is to complete most of the virtual development work in order to save the cost of prototype design and shorten the time to market for future mass-produced components." Relevant personnel said.