Overarching Research Project: Mass-production-ready Manufacturing Technologies for Extremely Thin-walled and Resource-efficient Components for the Production and Power Generation of Hydrogen for Energy Supply (ResKo-H2)
To achieve greenhouse gas neutrality and meet the targets of the Paris Climate Agreement, the German federal government is driving the rapid development of a hydrogen (H₂) economy. The goal is to accelerate the market ramp-up of H₂ technologies and establish robust value chains based on strong and sustainable domestic H₂ production and use. By 2030, a significant increase in H2 demand is expected, particularly in industrial and transportation sectors. A major barrier to realizing this growth is the still high cost of fuel cell (FC) stacks and their integrated components. In addition, current production technologies do not yet offer sufficient levels of automation or high-throughput capability.
Metallic bipolar plates (BPPs) are a key lever for both the cost and performance of fuel cell (FC) stacks and, together with membrane electrode assemblies (MEAs), form their core components. BPPs typically consist of two metallic half-plates with wall thicknesses of around 100 µm and account for approximately 60–85 % of the stack’s weight and about 55 % of its material costs. Reducing the wall thickness significantly below 100 µm would substantially reduce material usage and costs and enable more compact stacks. However, this is currently not feasible with state-of-the-art manufacturing technologies, particularly with regard to ensuring reliable, leak-tight (media-tight) operation. Against this backdrop, the ResKo-H2 research project – with the subprojects UmKE and H2-Direkt – addresses the challenge of leak-tight joining of ultra-thin metallic sheets with thicknesses well below 100 µm.
Project Objectives
The overarching objective of the project is to significantly reduce costs and/or increase the power density of H₂ components.
Within H2-Direkt, SME-compatible and scalable manufacturing processes for leak-tight metal-plastic joints in H₂ applications will be developed, based on the innovative thermal direct joining technology HPCi®. In addition to the strongly reduced target wall thickness of 50 µm, other established requirements for FC production will also be taken into account, such as short cycle times in the range of 10 seconds and long-term resistance to typical operating and cooling media such as H2, H2O, and O2.
To ensure rapid and broad market uptake of the joining technologies to be developed, methods for integrating these processes into industrial product development are required alongside technical implementation. H₂-Direkt addresses this essential aspect for broad industrial adoption through the creation of physical models of metal–plastic joints. This enables companies to design products to be “joining-ready” from the outset and to define joining points early in the development process. Physical modeling also makes it possible to transfer results obtained from the example of FCs within H2-Direkt to other H2 applications and to link them with findings from the partner project UmKE.
The economic benefit of the targeted research outcomes for small and medium-sized enterprises (SMEs) primarily lies in resource and cost savings during the production of components for H2 technologies, enabled by the use of significantly thinner-walled components. Particularly in the case of FCs, reducing wall thickness directly results in a significant increase in power density, as the volume of the FC stack decreases by around 30 % while maintaining the same number of cells. The joining and production techniques to be developed thus strengthen Germany’s position in the politically supported H2 market ramp-up and make an important and tangible contribution toward achieving decarbonization and resource-efficiency goals.
Furthermore, the research project enables companies to consider the technical and economic properties of directly joined metal–plastic connections right from the product design phase onwards. The user group for the research outcomes spans the entire value chain of fuel cells (FCs) and related H2 technologies. This includes suppliers of semi-finished ultra-thin steel sheets and plastic films, manufacturers of joining and production equipment, producers of metallic bipolar plates, and their customers, who benefit from anticipated material savings and increases in power density. Manufacturing companies seeking to enter or expand within the emerging H2 market via targeted investments receive concrete recommendations for action and digital models to support more efficient development and production processes and underpin sound investment decisions.
Fraunhofer Institute for Material and Beam Technology IWS