Next generation mobility solutions

The conversion of energy from chemical to electrical energy and vice versa generates heat. In the case of batteries, this heat can damage the cells and reduce their performance and service life. To prevent this, we are working on energy-efficient solutions for temperature control through the use of phase change materials (PCM). These are able to store high amounts of heat through the phase change solid-liquid and vice versa to release it again. Their high heat storage potential is countered by a very low thermal conductivity.

We investigate the paraffin-based latent heat storage for both cooling and heating scenarios and combine them with other temperature control systems for specific applications. We integrate the PCMs, among others in aluminum foams via infiltration processes. This creates a material composite that solves the problem of low thermal conductivity of the PCM for its thermal loading and unloading. At the same time, the excellent structural properties of the aluminum foam, such as energy absorption and vibration damping, can be used in appropriate applications. We also use our diverse measurement technology here for the thermal and mechanical characterization of the multifunctional composite material. Previous applications include the temperature control of battery cells, battery modules and power electronics.

• Use of phase change materials (PCM) for passive temperature control
• Development of application-oriented heat conduction structures such as closed-cell metal foams and integration of PCM into these structures
• Integration of PCM systems in active temperature control systems with the strategies:    

- Downsizing the active temperature control system

- Smoothing of thermal load peaks

- Increase in temperature homogeneity

- Prevention / delay of the thermal runway

Crash and intrusion protection structures offer high lightweight construction potential.

We focus among other things on light sandwich constructions, etc. with aluminum foam cores. These enable a high energy absorption capacity made possible by compacting the metallic foam. Compared to plastic foams, these foams are particularly notable for their properties of thermal conductivity, electromagnetic shielding and fire resistance. In addition, we examine crash-proof lightweight profiles and efficient process designs for the local reinforcement of metallic components using FRP.

The subject of research is, among other things, the protection of battery electrical systems based on aluminum foam sandwich sub-floor structures and laterally surrounding profiles.

In addition to the dynamic mechanical design, we carry out the metrological determination of selected parameters.

• Intrusion protection of underbody components or battery electrical systems through the use of lightweight materials such as aluminum foam sandwich structures
• Load path-appropriate energy absorption structures made of FRP / metal hybrids
• Local reinforcement of metallic components with FRP patches

The design and functionality of mobile interior is crucial for the customers acceptance. Its value will rise even more with the intensity of use and digitalization of tomorrows vehicles. The Fraunhofer Project Center Wolfsburg addresses applications such as automotive, shipping industry, rail sector and aerospace.

All of these industries are facing enforced requirements regarding sustainability and reduction of CO₂ emission which will lead into new vehicle concepts including their interior. The application of bio-based materials, energy efficient production processes and multi-functional, smart components will be in focus in industrial production scale.

At the Fraunhofer Project Center Wolfsburg holistic solutions integrating development of materials, production processes, circular economy and life cycle assessment are being established. Concepts and solutions are being based on lot size, part dimensions, human machine interaction or specific questions such as fire protection.

• Functional coatings for the automotive industry
• Leather for dashboards
• Vegan imitation leather
• Odor and coating of natural fibers in automobiles
• Decorative coatings on plastics, wood, metal or textiles
• Decontamination
• Integration of fiber optics in fiber reinforced plastics
• Sensor integration for condition monitoring in (autonomous) vehicles
• Sensors, actuators and displays for interaction with passengers
• Damage tolerance and easy to replace interior
• Sensitive surfaces
• Individual, changeable surfaces

Alongside the change to alternative and environmentally friendly driving systems, autonomous driving is one of the future topics of the automotive industry. Recognition of the environment is essential for autonomous vehicles. Various technologies are used for this, including radar and LIDAR sensor technology. The sensors are covered with plastic panels to protect them from environmental influences and for optical reasons. However, these screens and especially the paints that are applied influence the signals.

The Fraunhofer Project Center offers the possibility of examining the influence of plastic panels with various varnishes on the radar signal by producing different test specimens. The colour pigments used and their concentration are decisive for the effects on the signals. In the field of radar technology, metallic colour pigments in particular can influence the signal.

The topic of electromobility is gaining increasing importance, also in casting technology and the related development of new cast components. Particular attention is being paid to the development and testing of new casting concepts and design methods for the components of electric motors. The demands for a later transferability to series production are constantly being taken into consideration.

In the foreground stands, for example, the embedding of tubes or hollow structures in the housings for electric motors, batteries or power electronics, due to cooling aspects. Furthermore, measures for the optimization of cast rotors are being developed. The concept of the cast coil opens up completely new possibilities for performance increases compared to conventionally wound wire coils.

Through close interdepartmental cooperation with the Electromobility department, an optimal know-how constellation is being forged that enables a holistic consideration of the manufacturing technological aspects with a casting technological focus, constructive design, and electromagnetic interpretation for the successful manufacture of components for electric drives.

• Castings for electric drives