YCN Research in Spot: New materials for solid oxide fuel cell cathodes with superior performance and improved long-term stability by Christian Berger

The investigation of new energy systems becomes increasingly important, because of the high energy demand needed, at simultaneously reduced environmental impact. A significant share of energy is currently generated from fossil fuels, and this is a major issue concerning environmental pollution and impeded availability.

A very promising alternative technology is represented by solid oxide fuel cells (SOFCs). These highly efficient power-generating devices convert chemical energy into electrical energy and thermal energy.

During my doctoral thesis, I was working on the development of new materials for SOFC cathodes. An elementary component of my research describes the close linkage of structure and mass- or charge transport properties. For this task, the crystal structure analysis of mixed ionic-electronically conductive oxides, like perovskites and Ruddlesden-Popper phases, plays an important role. Beyond that, the aim of this thesis was to overcome some of the most important current issues in SOFC cathode development, such as degradation in cathode performance due to surface poisoning effects, limited cathode performance due to reduced oxygen exchange kinetics at intermediate temperatures, and insufficient thermal expansion compatibility between the cathode and the electrolyte.

My recent research interest focuses on the synthesis and characterization of self-organised proton conducting perovskite composites. These composites consist of a phase with good electronic conductivity and high catalytic activity for oxygen reduction, and another phase with good protonic conductivity. The final goal of this work is to obtain a deeper understanding of proton incorporation and oxygen reduction reaction, as well as a thorough understanding of defect chemistry in self-organized ceramic composites.

Christian Berger 
Second place at the 2019 ECerS Student Speech Contest

Actual Address (until 12.2020):
Chair of Physical Chemistry
Montanuniversitaet Leoben
Franz-Josef-Straße 18
A-8700 Leoben

Future Address (from 01.2021):
Physical Chemistry of Solids
Max Planck Institute for Solid State Research
Heisenbergstraße 1
DE-70569 Stuttgart