"Water electrolysis is the key technology for climate-neutral, green hydrogen – and central to compliance with the EU's Strategic Technologies for Europe (STEP) regulation. This is because hydrogen produced in Europe by electrolysis does not need to be imported, avoiding dependence on supplier countries outside Europe. This is particularly valuable when electrolysers are used that make a significant contribution to industrial value creation in the EU," explains Dr Marc-Simon Löffler, head of the electrolysis development department at ZSW.
Two electrolysis technologies are already in commercial use today: Alkaline electrolysis (AEL), with its high degree of technological maturity, is highly scalable and therefore particularly suitable for large hydrogen production plants. It does not require expensive and resource-critical precious metals and is therefore cost-effective, but its dynamic response to operating requirements is limited. Polymer electrolyte membrane electrolysis (PEMEL) delivers higher power density and also enables dynamic plant operation, but requires expensive and resource-critical precious metals such as platinum or iridium. The still young AEMEL technology (anion-conducting polymer electrolyte membrane electrolysis) combines the advantages of AEL (no use of precious metals) and PEMEL (high power density and dynamic operation). However, there is still a need for development at the component and stack level in order to achieve a level of maturity comparable to that of AEL and PEMEL.
From laboratory to prototype: the AEMEL stack
The production costs of green hydrogen via water electrolysis are a key factor in investment decisions. For the commercial success of AEMEL technology, it is therefore necessary to develop not only efficient and durable components, but also designs and production technologies that are suitable for series production, scalable and cost-effective.
This is precisely where the genAEMStack project comes in, with ZSW and Holst focusing on complementary areas: ZSW is concentrating on the design and manufacture of a scalable AEMEL stack suitable for series production and on modelling approaches for the membrane electrode assemblies (MEA). Initially, the researchers want to implement the stack on a laboratory scale in the electrical power class of around 10 kilowatts. In a later phase, the partners plan to scale the unit to a commercially relevant power class of over 100 kilowatts. The newly developed AEMEL components and stack prototypes are validated in the existing test benches at the ElyLab test centre at ZSW in Stuttgart.
In addition to cost structure analyses, the Holst Centre is focusing on the development of improved porous transport layers (PTL) with flow field integration, particularly catalytic coatings and protective coatings, the validation of innovations on a laboratory scale, and the integration of these novel technologies into next-generation electrolyser architectures.
The uniqueness of this collaboration lies in the cross-regional technological and commercial bridges. ‘The unique competencies of our two regions can complement each other, not only producing revolutionary technologies, but also orchestrating innovations with commercial partners from both regions’, comments Emilio Manrique, Business Development Manager at the Holst Centre.
Involvement of industry
The newly developed, manufacturer-independent AEMEL stack will be made available to interested companies as a basis for their own developments. Interested companies will be approached and involved in close cooperation with the innovation agency of the state of Baden-Württemberg, e-mobil BW, and the Brabant Economic Development Agency.