Publications by Stefan Diethelm

Advancing non-carbon energy: optimized and safely operated solid oxide fuel cell design for industrial feasibility

Stefan Diethelm, Jan Van Herle, François Maréchal, Shivom Sharma

As the world shift towards sustainable energy solutions, solid oxide fuel cells (SOFCs) using non-carbon fuels like ammonia and hydrogen emerge as promising pathways to produce clean energy and enhance conversion efficiency. However, current implementation ...

2025

Local electrochemical and thermal investigation of a segmented reversible solid oxide fuel cell and electrolyzer

Stefan Diethelm, Jan Van Herle, Zacharie Wuillemin, Audrey Désirée Wesoly, Hamza Moussaoui

A novel setup has been designed and mounted to investigate the local electrochemical and thermal behavior of a cell from a 4-cell short stack under reversible operation solid oxide fuel cell/solid oxide electrolyzer (SOFC/SOE). It consists in the partition ...

Pergamon-Elsevier Science Ltd2023

Operando analysis of a solid oxide fuel cell by environmental transmission electron microscopy

Stefan Diethelm, Aïcha Hessler-Wyser, Jan Van Herle, Quentin Thomas Jeangros, Cédric Frantz

Correlating the microstructure of an energy conversion device to its performance is often a complex exercise, notably in solid oxide fuel cell research. Solid oxide fuel cells combine multiple materials and interfaces that evolve in time due to high operat ...

Nature Portfolio2023

Degradation study of a reversible solid oxide cell (rSOC) short stack using distribution of relaxation times (DRT) analysis

Stefan Diethelm, Jan Van Herle, Maria del Mar Perez Fortes, Philippe Aubin, Suhas Nuggehalli Sampathkumar

Reversible solid oxide cells (rSOC) can convert excess electricity to valuable fuels in electrolysis cell mode (SOEC) and reverse the reaction in fuel cell mode (SOFC). In this work, a five - cell rSOC short stack, integrating fuel electrode (Ni-YSZ) suppo ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Integrated solar-driven high-temperature electrolysis operating with concentrated irradiation

Stefan Diethelm, Jan Van Herle, Sophia Haussener, Meng Lin, Clemens Gregor Suter

High-temperature electrolysis for reducing H2O (and CO2) to H2 (and CO) converts concentrated solar energy into fuels and chemical feedstock. We invented an integrated reactor concept comprising a solar cavity receiver for reactant heating, a solid oxide e ...

2022

Poisoning effects of chlorine on a solid oxide cell operated in co-electrolysis

Stefan Diethelm, Jan Van Herle, Guillaume Jeanmonod

Although the effects of impurities on the Ni-YSZ electrode of a solid oxide cell in fuel cell operation have been studied, reports on their effects during electrolysis operation are limited. Here, short-term experiments at various current densities and a d ...

ELSEVIER2021

In-situ experimental benchmarking of solid oxide fuel cell metal interconnect solutions

Stefan Diethelm, Jan Van Herle, Priscilla Caliandro, Manuel Bianco

The progress in the diffusion of solid oxide fuel cell (SOFC) as commercial devices is not paired by literature production. Articles describing the behaviour of SOFC stacks are rare because of confidentiality reasons for commercial suppliers while research ...

2020

Experimental characterization of a solid oxide fuel cell coupled to a steam-driven micro anode off-gas recirculation fan

Stefan Diethelm, Jürg Alexander Schiffmann, Jan Van Herle, Zacharie Wuillemin, Patrick Hubert Wagner, David Constantin

While the global fuel utilization of solid oxide fuel cells (SOFCs) is limited by the stack aging rate, the fuel excess is typically used in a burner, and thus limiting the system electrical efficiency. Further, natural-gas-fueled SOFCs require treated wat ...

2020

The effect of SO2 on the Ni-YSZ electrode of a solid oxide electrolyzer cell operated in co-electrolysis

Stefan Diethelm, Jan Van Herle, Guillaume Jeanmonod

In this work, the effect of sulphur poisoning of the Ni-YSZ electrode of an SOEC operated in co-electrolysis mode was investigated. Short-term tests with exposure up to 5 ppmv of SO2 were performed at OCV and under polarization (0.25 A cm−2). The two-stage ...

2020

Cyclic degradation analysis of reversible Solid Oxide Cell short-stack

Stefan Diethelm, Jan Van Herle, Maria del Mar Perez Fortes, Guillaume Jeanmonod, David Constantin, Philippe Aubin, Suhas Nuggehalli Sampathkumar

The deployment of renewable energy systems has been increasing steadily in recent years. The intermittency associated with the renewable electricity supply can be addressed through the usage of energy storage and release systems. In this framework, reversi ...

2020

Trade-off designs of power-to-methane systems via solid-oxide electrolyzer and the application to biogas upgrading

Stefan Diethelm, Jan Van Herle, François Maréchal, Guillaume Jeanmonod, Ligang Wang

Solid-oxide electrolyzer based power-to-methane is promising for large-scale energy storage as well as biogas upgrading by efficiently converting intermittent renewable power and CO2 (e.g., in biogas) into synthetic methane. Either air or pure oxygen can b ...

2019

Active Near-Infrared Imaging for Spatio-Temporal Monitoring of a Solid Oxide Cell in Operation

Stefan Diethelm, Jan Van Herle, Guillaume Jeanmonod

The characterization of solid oxide cells (SOCs) relies mainly on direct-current (DC) and alternating-current (AC) methods that provide only average surface electro-chemical responses. As such, the spatial distribution is not well captured and the complexi ...

2019

Design of a Pilot SOFC System for the Combined Production of Hydrogen and Electricity under Refueling Station Requirements

Stefan Diethelm, Jan Van Herle, François Maréchal, Maria del Mar Perez Fortes, Alberto Mian

The objective of the current work is to support the design of a pilot hydrogen and electricity producing plant that uses natural gas (or biomethane) as raw material, as a transition option towards a 100% renewable transportation system. The plant, with a s ...

2019

Model-assisted identification of solid oxide cell elementary processes by electrochemical impedance spectroscopy measurements

Stefan Diethelm, Jan Van Herle, Arata Nakajo, Priscilla Caliandro

Electrochemical Impedance Spectroscopy (EIS) is extensively used to characterize Solid Oxide Cells (SOCs) to extract information on the elementary loss mechanisms. However, these individual mechanisms usually overlap in the frequency domain, requiring dedi ...

2019

Power-to-methane via co-electrolysis of H2O and CO2: The effects of pressurized operation and internal methanation

Stefan Diethelm, Jan Van Herle, François Maréchal, Tzu-En Lin, Ligang Wang, Hanfei Zhang

This paper presents a model-based investigation to handle the fundamental issues for the design of co-electrolysis based power-to-methane at the levels of both the stack and system: the role of CO2 in co-electrolysis, the benefits of employing pressurized ...

2019

Power-to-fuels via solid-oxide electrolyzer: Operating window and techno-economics

Stefan Diethelm, Jan Van Herle, François Maréchal, Tzu-En Lin, Ligang Wang

Power-to-fuel systems via solid-oxide electrolysis are promising for storing excess renewable electricity by efficient electrolysis of steam (or co-electrolysis of steam and CO2) into hydrogen (or syngas), which can be further converted into synthetic fuel ...

2019

Optimal design of solid-oxide electrolyzer based power-to-methane systems: A comprehensive comparison between steam electrolysis and co-electrolysis

Stefan Diethelm, Jan Van Herle, François Maréchal, Maria del Mar Perez Fortes, Hossein Madi, Ligang Wang

Power-to-methane technologies have been regarded as a promising alternative to offer small or large-scale, long-timescale (daily/weekly/seasonal) energy storage as well as the opportunity of utilizing CO2. The performance of the core component, the electro ...

2018

Modeling and Designing of a Radial Anode Off-Gas Recirculation Fan for Solid Oxide Fuel Cell Systems

Stefan Diethelm, Jürg Alexander Schiffmann, Jan Van Herle, Zacharie Wuillemin, Patrick Hubert Wagner

To improve the industry benchmark of solid oxide fuel cell (SOFC) systems, we consider anode off-gas recirculation (AOR) using a small-scale fan. Evolutionary algorithms compare different system design alternatives with hot or cold recirculation. The syste ...

2017

Post-test Analysis on a Solid Oxide Cell Stack Operated for 10,700 Hours in Steam Electrolysis Mode

Stefan Diethelm, Jan Van Herle, Pierre Burdet, Emad Oveisi, Giorgio Rinaldi

A solid oxide short stack composed of 6 Ni-YSZ supported cells, YSZ electrolyte and GDC-LSC oxygen electrode has been tested for 10,700 hours in steam electrolysis. Initial degradation was followed by a global stabilization of the performance after lowerin ...

2017

Triode Solid Oxide Fuel Cell Operation Under Sulfur-Poisoning Conditions

Stefan Diethelm, Jan Van Herle, Priscilla Caliandro

The triode solid oxide fuel cell (SOFC) is a three electrodes configuration. The third electrode, so-called auxiliary, is connected in a way to run in electrolysis mode, while cathode and anode operate in normal fuel cell mode. This mixed operation allows ...

Wiley-V C H Verlag Gmbh2017