The Institute of Engineering Thermodynamics at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt - DLR) in Stuttgart, with further research facilities in Cologne, Ulm, Oldenburg and Hamburg, does research in the field of efficient energy storage systems that conserve natural resources, and next generation energy conversion technologies with a staff of 180 scientific and technical employees, engineers and doctoral candidates. The spectrum of activities ranges from theoretical studies to laboratory work for basic research and to the operation of pilot plants. These experimental and theoretical studies are accompanied by systems analysis studies to analyse the associated technological, environmental and economic potential and situate it in a larger overall context of the energy economy by means of scenarios. A tight network with the University of Stuttgart -especially with the Institute of Energy Storage- and with the Helmholtz Institute Ulm at the University of Ulm is existing.

Proton-conducting ceramic cells (PCC) have attracted much attention in recent years. Compared to state-of-the-art soli oxide cells (SOC), PCC presents the unique feature to transport protons through the electrolyte and operate at much lower temperature i. e. between 400°C and 650°C. The PCC architecture allows a nearly ideal fuel electrode configuration. In electrolysis (PCCEL) it enables production of pure, dry hydrogen streams at the fuel electrode and gives possibility to electrochemical compression of the produced hydrogen. Despite these promises, PCCEL is still a nascent technology compared to other electrolysis technology, the limited faradaic efficiency attained by state-of-the-art cells is a key challenge to address to enable the scale-up and deployment of the technology.

This limited faradaic efficiency caused by a p-type current leakage throughout the typical electrolyte materials under traditional steam electrolysis conditions. This Ph. D. work aims at optimizing cell design and operating conditions to maximize the performance and efficiency of PCCEL.

To this end, the addition of interlayers at the interface between the electrolyte and the oxygen electrode aiming at hindering the current leakage will be investigated. Furthermore, thin contact layers will be considered to enable the efficient use of thin film electrolyte and minimize the ohmic losses. The influence of electrolysis parameters (pH2O, T, flow, conversion rates, …) will also be investigated in order to define an optimal operating window for PCCEL, that maximizes the performance and faradaic efficiency.

The PhD work takes place in the framework of the EU project SUSTAINCELL aiming at the development of Durable and Sustainable component supply chain for high performance fuel cells and electrolyzers.

Your tasks:

• sample preparation / coating with materials
• experimental characterization (XRD, SEM) and Electrochemical characterization (EIS, DRT)
• participation to the EU project SUSTAINCELL / reporting
• writing publications