Electromobility – Plasma Treatment for Drive and Storage Systems
Wider use of electromobility is a critical issue for the future. New drive and storage systems are the focal points of development for all leading automobile manufacturers and electronics suppliers. The development of more effective drive motors (electric motors) with high efficiency as well as lighter and more efficient forms of energy storage (batteries, fuel cells) are critical for success.
Innovative material composites must be produced to manufacture high-performance systems of this type. In addition, the surfaces of the materials used must be functionalized selectively. Openair-Plasma® activation, combined with a PlasmaPlus® functional coating, offers industry a unique process, with outstanding results. Openair-Plasma® technology is perfect for this, both because of its simplicity of application and because of the characteristics created by its functional coatings.
High-performance batteries: inline plasma activation to reliably bond and seal housings
Advanced battery systems frequently consist of ingenious stacks of interconnected battery cells enclosed in a common housing. Often, non-polar acid-resistant materials like modified plastics are used, both in the coating of the stacks and in the subsequent joining and sealing process of the battery housing.
Openair-Plasma® pretreatment (plasma activation) makes it possible to efficiently activate the surfaces non-polar plastic and composite materials that can otherwise be processed only with difficulty. This plasma activation provides the ideal conditions for reliable bonding and sealing of battery housings. Openair-Plasma® technology, which is easy to integrate inline, makes an efficient process sequence possible without separate chamber systems. Openair-Plasma® is thus ideally suited for fully automated pretreatment in manufacturing batteries in high quantities and at high process speeds.
Advantages of Openair-Plasma® pretreatment during bonding and sealing of battery housings:
- Extremely high degree of activation, incorporation of up to 30% reactive groups (for example, oxygen functionalities)
- High process speed
- Optimal process control
- Simple inline integration
in the manufacture of
electric drive and storage systems
- Selective hydrophilic/hydrophobic plasma coatings for transporting water out of fuel cells
- Partial electrically-insulating plasma coating with defined dielectricity (insulation coating)
- Wear protection coatings for electrode systems
Electrically insulating, hydrophilic and hydrophobic nanocoating for robust and fail-safe fuel cells
The fuel cell is among the most promising and furthest developed technologies in the area of electromobility. Today fuel cells are already being used to drive ships, submarines, special vehicles and even research planes.
However, the big breakthrough in this technology hasn’t happened yet as far as the future of the automotive industry is concerned. Cost reduction for the materials used and expansion of operating ranges remain critically important for the quality and safety of fuel cells.
In particular, the cooler operating ranges of fuel cells represent a problem because during the conversion of hydrogen and oxygen to energy, water inevitably occurs. In spite of extremely low temperatures, this water must be safely blown out of the fuel cell in order to protect the complicated bipolar plates from bursting during freezing.
Plasma technology, and especially plasma coating (plasma polymerization), play an important role in the two focal points of development:
- Electrically-insulating functional coating. With the use of PlasmaPlus® nanocoating, a selective electrically-insulating functional coating is applied that makes it possible to use a variety of membrane materials.
- Hydrophilic/hydrophobic nanocoating. Providing the membrane materials with an appropriate plasma functional coating makes it possible to blow out (drain) water from the fuel cell.
Forming gas plasma for safe contact cleaning for fuel cells and batteries
Usually Openair-Plasma® systems are supplied with compressed air as the assist gas. However, if an oxide layer is to be removed from surfaces, the assist gas is simply replaced with a mixture of gases and appropriate functional constituents. Forming gas, a mixture of nitrogen and hydrogen, is especially suitable for such plasma cleaning. The hydrogen is supplied in a non-critical, non-explosive mixture ratio (no greater than 5%).
The characteristics of the resulting forming gas plasmas differ completely from those of the usual Openair-Plasma®. Instead of incorporating oxygen in the surface of the material, it is securely removed by the plasma treatment. Even highly oxidized copper surfaces are bare again in a short period of time. This form of plasma cleaning leads to safe contact cleaning and therefore to reliably reproducible soldering and coating processes that are of fundamental importance for fuel cells and batteries.