Lorenz Kunststofftechnik GmbH joined Vestaro GmbH, Forward Engineering GmbH, Evonik Resource Efficiency GmbH, LION Smart GmbH, and Minth GmbH to form a development consortium. Drawing on accumulated expertise, the group initially designed a cost-effective glass fiber Epoxy-SMC cover for high-voltage batteries based on Evonik’s high-performance epoxy curing agent VESTALITE S.
The partner companies have developed a new generation of high-performance battery packs for electromobility.
Aluminum sandwich plate improves performance and vehicle integrationIn most e-vehicles, the battery pack is in the floor area to improve the center of gravity and driving performance, and to provide more space in the vehicle cabin. This design increases the risk of dangerous battery damage from impact situations or objects hitting the underside of the vehicle, such as loose stones or branches so special protective measures must be taken to prevent deformation or the ingress of foreign objects.
To fulfill the stringent requirements, the consortium designed a novel approach that takes maximum advantage of the design freedom of the proven SMC material.
The old floor structure was replaced by an aluminum sandwich plate developed by Minth. The group got rid of additional side-mounted deformation elements and use the freed space for battery cells. Using Forward Engineering’s BEV-floor structure development tool, the Pure Performance Battery was configured and validated so improved impact behavior of the sandwich floor could be achieved, and reduce the space required for module assembly. The capacity could be increased by 10 kWh to a total of 75 kWh with approximately the same external dimension of the battery pack.
Modular design and Epoxy-SMC housing boost performanceThe new Pure Performance Battery can be for example 2.1 m long and 1.58 m wide or other dimensions, with maximum heights between 0.15 and 0.22 m, enabling vehicle architectures. Regarding the ergonomic design, it competes with other high-end solutions, but surpasses them in terms of performance. The modular series design of the battery also allows flexible adjustment of the number of modules. The supercell concept based on LION Smart’s LIGHT Battery enables a calculated fast charging result of around 13 min for a charging power constantly above 200 kW (10 to 80 percent SOC). The system is currently being used to achieve a charging time of less than 10 min in the future.
The cover made of glass fiber-reinforced Epoxy-SMC from Lorenz Kunststofftechnik not only stands out for its low weight but provides very high safety potential in terms of fire resistance and crash behavior.
All concerns regarding the EMI-shielding performance of the glass fiber composites could be tackled with a broad material toolbox and validated under OEM requirements. The process benefits were verified by manufacturing several complex demonstrator geometries. During these trials, cycle times of around 3 min could be realized, suggesting a high cost saving potential.
Resource efficiency thanks to recycling system and “mix-and-match” serviceThe new generation of high-voltage battery packs has not only been improved in terms of performance.
For example, the cover can be disassembled by undoing several screw connections to enable easy access to the battery modules and peripheral equipment. Unlike bonded systems, the Pure Performance Battery allows individual components to be replaced and repaired. The battery cover out of Epoxy-SMC itself can be recycled by Lorenz Kunststofftechnik and afterwards reused in new composite parts.
Overall, the consortium partners have once again learned a lot from each other during the development process of the new battery pack generation to supply the customer with an all-round finished battery pack. Given the dynamics of the industry, all project partners are prepared to handle requests from potential customers that deviate from the basic model and to offer a collaborative “mix-and-match” service.