Range and charging performance are key factors in the acceptance of electromobility and determine the competitiveness of the manufacturing companies. Important elements of a battery system for electric cars are not only the battery module itself with its cells, but also the housing with structures for load distribution and temperature regulation, frames, lids and base plates, which in their entirety must protect against overheating and prevent damage to the battery core in the event of accidents.
There is still a lot of optimisation potential for function-integrated lightweight construction and resource efficiency in battery housings commonly used today, finds Rico Schmerler, research assistant at the Fraunhofer IWU at the Fraunhofer Project Centre Wolfsburg and coordinator of 'CoolBat'. "That is why we have set our sights on this assembly. We want to develop and test CO2-saving solutions for next-generation housings." The research results will later be transferred to other applications and industries where large batteries are used.
One of the development goals of the project partners is to integrate more functions in a smaller installation space with fewer interfaces. To achieve this, individual systems are combined into functionally integrated structures that combine thermal and mechanical tasks. For example, load-bearing structures have temperature control channels cast directly into them and the function of the cooling unit is combined with that of crash protection in floor panels. The researchers achieve this with aluminium foam. The lightweight material absorbs a lot of impact energy in the event of an accident. In combination with phase change material (PCM), it also reduces the energy required to cool the battery. Fraunhofer IWU has two decades of experience in the development and application of metallic foams.
The institute also contributes its expertise in the use of lightweight materials and technologies to the design and production of the load-path-optimised battery housing cover. In addition, new heat conducting materials are being developed and tested in the