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Reference : UMR6502-OLIJOU-002
Workplace : NANTES
Date of publication : Thursday, July 23, 2020
Scientific Responsible name : Prof. Olivier JOUBERT
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2020
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Background of the PhD project:
Electrolysis and green hydrogen will play a key role in the near future to defossilize industrial processes that are CO2 intensive such as the production of synthetic chemicals or fuels and hydrogen for other industrial applications. As an intermediate step in the energy transition, recycling of waste heat from CO2 intensive processes, such as methanol synthesis, in high temperature electrolysis is essential to increase its yield and reduce emission of CO2.
Operating typically between 400°C and 600°C, ceramic Proton Conducting Cells (PCC) are particularly promising for such applications since they combine advantages of both high temperature Solid Oxide Cells (SOC) based on an anionic conductor and low temperature Proton Exchange Membrane cells (PEM): (i) the operating temperature range offers higher yield compared to PEM cells, (ii) consumption of steam takes place at the air electrode without mixing with the hydrogen produced. These features make those cells highly flexible and of particular interest for Energy Systems and Chemical Industry. However, the development of PCC is still behind the development of conventional SOC or PEM.
The main focus of this project will be the development of better ceramic proton conductors to act as electrolyte, and high performance air electrodes. The strategy will be to play on the composition, microstructure and ceramic forming methods of each cell components. A first axis will be dedicated to the optimization of proton conductivity in the electrolytic materials based on BZCY type (BaZr1-x-yCexYyO3 α) in order to reach a level of up to 10-2 S·cm-1 at 600 °C. A catalytic approach using Ni nanoparticles, which has already been tested successfully for equivalent compositions, will be tested, characterized and optimized. The second focus of the thesis will be to produce air electrode materials by screen printing, with an optimization step of the sintering temperature of the layer in order to keep the preparation temperature below 850 °C. The objective is to obtain a 30 µm thick layer, with at least 30% porosity. A main objective will be the adherence and interface properties/reactivity of the electrode material with the electrolyte to achieve performance at the level of state of the art SOC electrodes. Two approaches will be considered: (i) reducing the grain size of the electrode material and/or (ii) developing new electrode compositions.
The thesis work is part of the France-Germany collaboration through the ARCADE ANR project, focused on developing a low cost and innovative Metal Supported Proton Conducting Cell at an industrially relevant scale (ca. 100 cm² cells), targeting Green Hydrogen production and Power to X application.
The student will be based at the Materials Institute of Nantes (IMN, Institut des matériaux Jean Rouxel), one of the leading materials research centers in France, consisting of approximately 200 people (https://www.cnrs-imn.fr/), in the Electrochemical Energy Storage and Transformation group (ST2E). At IMN, researchers from the ST2E team have strong expertise in the field of ceramic materials for high temperature fuel cells and electrolysers (SOFC and SOEC). With their know-how in synthesis and more generally in solid chemistry, they have developed new electrodes and electrolytes materials.
Based in Nantes, the candidate will also have the opportunity to go on short missions at the EIFER research institute in Karlsruhe (Germany), partner of the ARCADE project, for a total of 10 months in order to develop the air electrode and perform additional experiments
Constraints and risks
The candidate will have to travel between Nantes and Karlsruhe (Germany)
Profile of the Prospective Candidate:
Graduate from a master degree program or equivalent, the candidate must have training in ceramic materials synthesis (solid state reaction, Pechini, soft chemistry), characterizations (chemical analysis, X-ray diffraction, spectroscopy and microscopy), and electrochemical characterizations (electrical conductivity measurements, impedance spectroscopy). He/She will take part in research activities of the team and will have the opportunities to present their work in national and international conferences. A high level of English is required. The candidate will be working under the guidance of 4 researchers at IMN (Annie Le Gal La Salle, Eric Quarez, Olivier Joubert, and Clement Nicollet) and one researcher at EIFER (Julian Dailly).
Registration for a thesis will take place at the University of Nantes at the 3M doctoral school.
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