A consortium consisting of Lorenz Kunststofftechnik, Forward Engineering, Evonik, LION Smart, Vestaro, and Minth has developed an electric vehicle battery housing solution that improves vehicle efficiency through a lightweight structure while at a lower cost.
This solution reduces the weight of the battery by about 10% compared to other commonly used material combinations without sacrificing mechanical performance. In addition, the glass fiber reinforced epoxy SMC developed for the battery case can meet all fire resistance requirements and adapt to complex geometries. At present, the entire concept has been tested and is suitable for mass production, and it is safe even under extreme conditions.
Peter Ooms, Chief Operating Officer of Lorenz Kunststofftechnik GmbH said: "In 2019, under the leadership of VESTARO GmbH, we will cooperate with Forward Engineering, Evonik and LION Smart. The goal is to develop a series of battery concepts suitable for pure electric vehicles. We. Focus on the formulation of glass fiber reinforced epoxy SMC, so that it can not only meet all requirements in terms of safety and processability, but also re-enter the material cycle process." In 2021, Chinese automotive supplier Minth Group (Minth Group) Minth GmbH in Europe also joined the consortium.
Ooms said: "For the battery case, we use Evonik's VESTALITES epoxy curing agent to develop a new SMC with a density of 1.5-1.7g/cm3. This material has excellent properties, such as bending strength> 350 MPa, flexural modulus of elasticity> 18,500 MPa, impact resistance> 150kJ/m2. Using epoxy resin instead of the usual polyester resin can avoid other common problems when using glass fiber reinforced SMC materials. With VESTALITES Epoxy Lorenz SMC can process molding materials into complex geometries without sticking to the mold." In addition, Lorenz has established a process for recycling glass fiber reinforced SMC materials, taking into account the sustainability requirements of the automotive industry. Important considerations. "
The partner chose aluminum as the battery housing support structure to achieve a simple geometric structure and reduce production costs. Philipp Taschner, a project engineer at VESTARO GmbH, said: “The bottom plate is the foundation of the entire battery structure, with cross members for installing battery modules. The carrier plate of the battery management system is also connected to the aluminum base.” Two aluminum deformation elements provide absorption functions. The necessary side impact protection. The battery cell module alignment can realize electrode separation, thereby providing higher safety in the event of a collision, and easier cooling.
The super cell concept of LION Smart is used in the battery. Taschner said: “The battery cell is designed to achieve fully automated production and is cost-effective. In addition, the battery design is particularly safe because each cell is enclosed in a non-flammable medium coolant.” This not only provides In order to achieve higher safety, it also ensures that the battery continues to maintain a low average temperature and delays the aging of the battery. The modular series connection design of the battery allows flexible selection of the number of modules, and the overall height is very low, only 90mm.
Oom pointed out: "During the thermal 2D simulation of the battery pack, the insulation performance of the epoxy SMC case stood out. Our material can withstand 10 minutes at 800°C without burning, and its insulation performance can protect the surrounding components. And the material is not affected by the temperature above 300°C. During the test, the curing time of 3 minutes is achieved without the workpiece sticking to the mold. In addition, VESTALITES SMC does not produce styrene emission, only a small amount of volatilization VOC emissions."
The group offers several configurations for this battery concept. Taschner concluded: "At present, we can provide three energy configurations. In terms of energy density, safety and cost, it is comparable to or better than the battery models on the market. Under 65kWh, the total weight is 412.1 kg; 85 kWh It is 527.3 kg; in a 120 kWh, 800V configuration, it is 789.2 kg. This overall concept is modular and provides flexibility."