Herstellung und Charakterisierung neuer langzeitstabiler Anodenmaterialien für die Hochtemperaturelektrolyse

Translated title of the contribution: Preparation and characterisation of new long-term stable anode materials for high-temperature electrolysis

Kathrin Sampl

Research output: ThesisMaster's Thesis

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Abstract

To increase the use of electricity from renewable energy sources, energy storage is needed on a large scale to compensate for fluctuations in energy supply. A promising storage medium is hydrogen, which can be produced with high efficiency by high-temperature electrolysis of water from renewable energy sources. When electricity is needed, the hydrogen produced can be converted back into electrical energy via high-temperature fuel cells or used to convert carbon dioxide into synthetic, carbon-based fuels. In this Master's thesis, the materials La2Ni0,8Co0,2O4+δ and La1,8Pr0,2Ni0,8Co0,2O4+δ are investigated for their suitability as oxygen electrodes for high temperature electrolysis cells for the production of hydrogen. The materials require sufficient oxygen ion conductivity as well as electronic conductivity for this purpose. Therefore, conductivity relaxation measurements are carried out to determine the surface exchange coefficients and diffusion coefficients of oxygen as well as electronic conductivity measurements. High-temperature electrolysis cells are also produced from the materials, which are then examined for their performance. The results show that the material properties such as electronic conductivity, surface exchange and diffusion coefficients of La2Ni0,8Co0,2O4+δ and La1,8Pr0,2Ni0,8Co0,2O4+δ hardly differ from each other and the corresponding activation energies are also very similar. It is confirmed that the investigated nickelates have a lower activation energy for oxygen diffusion than perovskites. However, in contrast to the literature, the activation energies for surface exchange of oxygen are higher. The performance of the cells with La2Ni0,8Co0,2O4+δ as anode material does not prove to be exceptional, but can be noticeably improved by doping with praseodymium.
Translated title of the contributionPreparation and characterisation of new long-term stable anode materials for high-temperature electrolysis
Original languageGerman
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Sitte, Werner, Supervisor (internal)
  • Egger, Andreas, Co-Supervisor (internal)
Award date1 Jul 2022
Publication statusPublished - 2022

Bibliographical note

no embargo

Keywords

  • High-temperature electrolysis cell
  • SOEC
  • anode
  • nickelate

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