As part of the ZIM research project "Additive Manufacturing of Lightweight Fuel Cells" - ALF, an innovative PEM fuel cell stack for aerospace applications was developed in cooperation with the Zentrum für angewandte Luftfahrtforschung GmbH (ZAL), focusing on the design of a compact lightweight bracing system.
On the part of ZBT, a simulation model was developed for the structural-mechanical optimisation of plastic-based end plates in order to achieve an improved weight respectivly material distribution of the end plates with sufficient stability. By combining the optimised end plate structures with flat-acting clamping elements, an additional improvement of the stack mechanics could be achieved resulting in a lower material load on the FC components and a more homogeneous contact pressure distribution inside the stack.
To validate the simulation results, ZAL focused on additive manufacturing of the end plate structures using the FDM method. Hereby geometric restrictions due to the manufacturing process could be reduced to a minimum. Furthermore, integral construction methods were taken into account, which reduced not only the system complexity but also the assembly effort and -time required for stack construction. The functional flexibility of this manufacturing process thus significantly accelerated the development of the end plates while simultaneously saving costs.
The qualification of the end plates with regard to fuel cell suitability was again carried out at the ZBT obtaining special consideration to the sealing properties and the contact pressure distribution within the stack. In final laboratory tests, the functionality of the newly developed bracing system was proven. In terms of performance it is equivalent to conventional stack bracing using aluminium end plates and tie rods. The substitution of the weight-driving metallic end plates with structurally optimised plastic end plates led to a weight saving of 57%.
- Department Fuel cell stacks
- Partner: ZAL.aero
