Flying is to become more environmentally friendly. However, the requirements for alternative drives in aviation are very high. Above all, they must be particularly light and powerful. Together with its partners, ZBT is developing an optimised fuel cell stack for a hydrogen drive for aircraft. The goal of the project with the short title KT2GP (KeyTechToGreenPower): a power density of more than 6 kW/kg.
To achieve this, the weight of the stack must be greatly reduced. To this end, the project partners are analysing and optimising the entire process chain for manufacturing titanium bipolar plates, from forming, cutting and joining to sealing, in order to identify and exploit optimisation potential. For example, heavy stainless steel is to be replaced by lightweight materials such as titanium for the bipolar plates. To achive this, the entire production technologies for titanium bipolar plates are being analysed with the help of all project partners.
ZBT optimises gasket application
Within the project, ZBT is focussing on the process of gasket application using dispensing technology for the robust use of extremely compact bipolar plates. To this end, a highly integrated sealing system is being developed, taking into account minimum cord thicknesses with optimised materials, optimised media tunnelling concepts and the integration of the sealing groove on the welding contour for the bipolar plate.
ZBT is also developing suitable qualification concepts to monitor the process quality and ensure the long-term stability of the components at seal and bipolar plate level – always with the specific requirements of the aviation application in mind, of course. To analyse the sealing materials, hydrogen permeation is measured on the one hand. Secondly, these materials are assessed when applied to the bipolar plate using a newly developed optical quality assurance system. In addition, the coatings for the bipolar plate are examined at ZBT using corrosion current measurements (ex-situ) and resistance measurements and in single-cell fuel cell operation (in-situ) with aviation-specific operating behaviour.
Two stacks and fully automated assembly
A total of two complete stacks with a power density of more than 6 kW/kg are to be manufactured in this project. Furthermore, an assembly island for stack assembly will be set up in order to assemble the fuel cells fully automatically into a stack.
After the project, the fuel cell system will be validated and verified in a ground test. The aim is to demonstrate its suitability for aviation applications using hydrogen as an energy carrier.
Title of the project:
Manufacturing technologies for titanium bipolar plates (BPP) and stack assembly as an enabler technology for fuel cell systems in aviation
Project acronym: KT2GP (KeyTechToGreenPower)
Approval period: 1 November 2023 to 31 December 2026
Funding reference: 20N2204E
