Publications de Jan Van Herle | EPFL Graph Search

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This study aimed to develop a dense protective coating of Mn 1.7 Cu 1.3 O 4 spinel on SOC interconnects using inkjet printing. The work focused on formulating a well‐dispersed, stable, and agglomerate‐free ink to obtain a dense, uniform, and full surface coating layer. Achieving a dense layer, requires an ink with high powder content. However, highly loaded inks increase the risk of agglomeration and nozzle blocking. This makes the colloidal stability and dispersion properties critical. Mn 1.7 Cu 1.3 O 4 co

On-line control and optimization can improve the eﬃciency of fuel cell systems whilst simultaneously ensuring that the operation remains within a safe region. Also, fuel cells are subject to frequent variations in their power demand. This paper investigate ...

This study investigates the potential application of total harmonic distortion (THD), as a fast online monitoring tool, to identify the early signs of failure modes in solid oxide fuel cells (SOFC). Indeed, the timely detection and identification of faults ...

(La0.6Sr0.4)(0.95)FeO3-delta/Sm0.2Ce0.8O2 (70:30, w/w) and (La0.6Sr0.4)(0.995)Co0.2Fe0.8O3-delta/Gd0.1Ce0.9O2 (50:50, w/w) cathodes screen printed on anode-supported cells were tested for 500h under different conditions by using a Taguchi matrix that combi ...

Electrochemical techniques were applied to a coulometric titration cell to study oxygen nonstoichiometry and transport in the perovskite-type oxide La0.4Ba0.6Fe0.8Co0.2O3-delta. Slow scan voltammetry (3mV/s) was used to obtain oxygen nonstoichiometry vs. the oxygen partial pressure (p(O2)) data. The voltammograms were further analysed using a simple defect model to yield the absolute value of the oxygen nonstoichiometry. Relaxation measurements were performed to obtain chemical diffusion and surface exchang

This paper reports on medium term tests of anode-supported five-cell short stacks, as well as on some separate anode development. Two stacks were operated under steady-state conditions: one with unprotected metal interconnects, H-2 fuel and 0.35 A cm(-2) ( ...

Spatially resolved analyses, by energy-dispersive X-ray spectroscopy (EDS) scanning electron microscopy (SEM), allowed the quantification of exogenous Si contamination in a solid oxide fuel cell (SOFC) cathode after operation. The Si quantification, taking ...

Coatings on SOFC interconnect steels are complex and challenging to investigate due to the high number of chemical elements which are present and interact with each other. In this work, advanced electron microscopy techniques are used to study the steel oxidation in its initial stage (first days), where scale is built up and first elemental diffusions and interactions may be clearly seen. First the surface of a coated steel piece is observed in an environmental scanning electron microscope (E-SEM) at high t

Degradation observed on long term stack tests may be explained in part by microstructural changes of the electrodes. Particularly at the anode side, the coarsening of nickel particles will affect its performances. Increasing the metal particle size will first diminishes the Three-Phase Boundary (TPB) where fuel oxidation takes place, and secondly decrease the electronic conductivity [1]. In order to quantify the changes in anode microstructure, SEM images analysis is used. Some techniques can be time consum

Three perovskite-type compounds of composition La0.4Ca0.6Fe1-xCoxO3-d (x=o, o.25 and 0.5) were investigated for use as oxygen separation membranes for the partial oxidation (POX) of methane to syngas. Special attention was given to the question of their stability in real operating conditions. A permeation set-up was specially designed to measure oxygen fluxes through these materials when placed in a strong pO2 gradient. It also facilitated testing the long-term stability of the specimen. Permeation measurem

Despite being a mature technology, solid oxide fuel cell (SOFC) devices are still limited by lifetime issues. In SOFC stacks, cell/interconnect interaction is the main responsible for voltage degradation at the oxygen electrode side. Corrosion and chromium ...

The perovskite-type mixed oxide La0.3Sr0.55Ti0.95Ni0.05O3-delta (LSTN) is demonstrated to exhibit the remarkable property of structural regeneration, where Ni can be reversibly exsoluted from the host perovskite lattice resulting in a regenerable Ni cataly ...

Nickel foam substrates are frequently utilised as porous 3D substrates for renewable energy applications. The preparation of these substrates usually includes an acid-washing step, but the degree to which this step affects the final electrochemical perform ...

Dense planar and tubular oxygen separation membranes of La 0.6Ca0.4Fe0.75Co0.25O3-d were investigated as reactors for the partial oxidation (POX) of methane to syngas. Disk-shaped membranes were prepared by compaction and tubes by extrusion. Their permeation properties were measured in an air/argon pO2 gradient as a function of temperature. At 900°C, the oxygen flux through a 1.26 mm thick membrane was 0.075 micromol/cm2s and through a 0.25 mm thick tube, 0.24 micromol/cm2s. For the POX measurements, a cata

Carbon deposition during the co-electrolysis of CO2 in solid oxide electrolysis cells (SOECs) poses a serious threat to cell structural integrity. Traditionally, it has been believed that carbon accumulates at the interface between the fuel electrode and the electrolyte. However, in this work, we report a novel phenomenon: the occurrence of internal short-circuiting during carbon deposition. This is evidenced electrochemically by a drop in open circuit voltage (OCV), the appearance of an inductive arc or ab

Environmental transmission electron microscopy was used to characterize in situ the reduction and oxidation of nickel from a Ni/YSZ solid oxide fuel cell anode support between 300-500°C. The reduction is done under low hydrogen pressure. The reduction init ...

Structural reliability and durability is a hurdle for the large-scale commercialisation of solid oxide fuel cell (SOFC). Because of the multiphysics nature of the problem, modelling is required to first gain knowledge and then alleviate mechanical failures. This chapter places the emphasis on stress analysis at the SOFC stack scale. A brief overview on the mechanical behaviour of the cell, sealing and gas diffusion layer materials is provided, along with a discussion on their implementation in finite-elemen

Understanding of mechanisms affecting degradation, durability and performance of solid oxide fuel cell (SOFC) stacks and integrated systems has become important due to increasing worldwide deployment. A novel simulation approach accounting for state-of-the ...

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 ...

Jan Van Herle

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Inkjet Printing Towards Dense Spinel Protective Coatings for Solid Oxide Cell (SOC) Applications

Robust Real-Time Optimization of a Solid Oxide Fuel Cell Stack

Fast online diagnosis for solid oxide fuel cells: Optimisation of total harmonic distortion tool for real-system application and reactants starvation identification

Stability of ferritic perovskite cathodes in anode-supported solid oxide fuel cells under different processing and operation parameters

Electrochemical characterisation of oxygen nonstoichiometry and transport in mixed conducting oxides : Application to La0.4Ba0.6Fe0.8Co0.2O3

Ageing of anode-supported solid oxide fuel cell stacks including thermal cycling, and expansion behaviour of MgO-NiO anodes

Glass-Forming Exogenous Silicon Contamination in Solid Oxide Fuel Cell Cathodes

Ageing of anode-supported solid oxide fuel cell stacks including thermal cycling, and expansion behaviour of MgO–NiO anodes

Live observation of the oxidation of coated interconnects with environmental electron microscopy

Methods for quantification of anode support microstructure

Oxygen permeation and stability of La0.4Ca0.6Fe1 - xCoxO3-delta (x=0, 0.25, 0.5) membranes

Degradation analysis of commercial interconnect materials for solid oxide fuel cells in stacks operated up to 18000 hours

Sulfur Poisoning Recovery on a Solid Oxide Fuel Cell Anode Material through Reversible Segregation of Nickel

How Acid Washing Nickel Foam Substrates Improves the Efficiency of the Alkaline Hydrogen Evolution Reaction

Planar and Tubular perovskite-type membrane reactors for the partial oxidation of methane to syngas

Carbon Deposition Induced Short Circuit of YSZ Electrolyte in Solid Oxide CO2 Electrolysis

In situ Reduction and Oxidation of Nickel from Solid Oxide Fuel Cells in a Transmission Electron Microscope

Current State of Models for the Prediction of Mechanical Failures in Solid Oxide Fuel Cells

The Effects of Dynamic Dispatch on the Degradation and Lifetime of Solid Oxide Fuel Cell Systems

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