Achieving an even higher range without exhaust fumes: The automotive industry and the aerospace industry are increasingly focusing on alternative forms of propulsion and are also considering hydrogen-powered fuel cells in their deliberations.
The Fraunhofer Institute for Production Technology IPT from Aachen, together with five partners from industry and science, is working on new concepts and systems for the “FlyGO” research project in order to reduce the previously high production costs of fuel cells and to open the way for new hydrogen-electric drives the mass production.
The manufacturing costs of the fuel cells are to be significantly reduced by a large-scale production chain of required components. So-called bipolar plates account for a large proportion by weight of the fuel cell and cause up to 45 percent of the production costs of a cell. In large quantities, they offer considerable savings potential.
To produce these thin sheet metal plates with a thickness of one-tenth of a millimeter, the sheet is processed by forming and cutting processes. Subsequently, two plates are welded together, coated and provided with a seal. For the surface structure of the bipolar plate, high degrees of deformation at channel depths of up to 0.8 millimeters with the smallest possible radii are required. Depending on the plate geometry, cracks in the sheet can occur during production using conventional forming processes.
Hot forming of bipolar plates paves the way for mass production and should reduce manufacturing costs
By local heating, the engineers at the Fraunhofer IPT want to improve the formability of the sheet metal material titanium and stainless steel (1.4404, 1.4301) and thus prevent cracks and thinning. The number of required processing steps should also be reduced and tool wear reduced. Titanium, for example, is a light metal that can further reduce the weight of the fuel cell, but it is brittle and is difficult to reform at room temperature. Hot forming promises a new application of titanium as a sheet material for bipolar plates.
To ensure that the thin sheet metal plates do not break during processing, the Aachen engineers examine how the forming process and the heating system are to be designed. First interim results for the process design were provided by the simulation of the investigated forming processes rubber forming, stamping, and hydroforming. The new concept for mass production, developed by the Fraunhofer IPT together with its partners, covers the entire process chain from hot forming to welding, coating and assembly.
New concepts for the series use of fuel cells in vehicles and aircraft
In addition to reducing fuel cell costs, the FlyGO project also includes two further developments: On the one hand, the project partners are developing a concept for integrating a hydrogen range extender into a battery-powered electric vehicle. As an example, they use a vehicle from the Aachen-based manufacturer e.GO Mobile AG, which has a longer range thanks to the integration of the fuel cell system. On the other hand, the partners are working on a gas-cooled hydrogen fuel cell in combination with a methanol electrolyzer, which can have more power per mass than conventional fuel cell systems. This should allow the use of the fuel cell in short-haul aircraft and drones.
Fraunhofer IPT introduces manufacturing of bipolar plates at »Blechexpo«
From November 5 to 8, 2019, the Fraunhofer IPT is showing how fuel cells can be mass-produced economically and in series at the »Blechexpo«, the international trade fair for sheet metal processing in Stuttgart. In hall 3, booth 3214, visitors will get a preview of the future large-scale production of bipolar plates. In addition to the system technology for processing high-strength and brittle materials with the help of heating technologies such as laser, induction and conduction, the Aachen researchers also show examples of components produced by such hot forming.
Partner in the project »FlyGO«
- e.GO Mobile AG, Aachen
- Fraunhofer Institute for Production Technology IPT, Aachen
- KCS Europe GmbH, Monschau
- PSL Technik GmbH, Oberhausen
- Center for Fuel Cell Technology ZBT GmbH, Duisburg
- Air s.Pace GmbH (associated), Aachen
The project “FlyGO – Fuel Cell Assisted Mobility for Green Vehicles and Aircraft” is funded by the European Regional Development Fund (ERDF) 2014-2020 (Grant No .: ERDF-0801224).