Vortrag: Electrode design for high temperature, solid state electrochemical energy conversion and storage devices

Solid state electrochemical cells are to date developed as solid oxide fuel and electrolyser cells operating at temperatures above 500 °C and converting chemical energy into electrical energy and vice versa. Compared to low temperature fuel cells and electrolysers, these cells offer several advantages such as fast reaction kinetics, high conversion and efficiency, and the ability to convert carbon containing gases that results in fuel flexibility and potential for CO₂ utilisation. The solid oxide cell (SOC) is an all-solid-state multilayer assembly with different (and also multiple) functionalities within the individual layers. Furthermore, the high operating temperatures pose several additional requirements on the materials, fi. matching chemical and physical properties to keep the solid-state cell intact during operation as well as during start-up and shut down. State-of-the-art electrode materials suffer from compromising functional, structural, and physical-chemical properties, which still triggers the search for alternative electrode materials and concepts.

In this presentation, the key requirements for both the fuel and air electrodes in solid oxide cells will be briefly introduced and approaches to novel, optimized electrodes presented. The design strategies start from chemical modification of the materials tailoring both, electronic and ionic conductivity, up to structural modifications leading to graded microstructures and allow to decouple the various functions in the electrode, esp. structural support, electronic conductivity and electro catalytic activity. The presentation will give examples on how different functionalities can be individually tailored in these multilayer cells and which design options are available for technically relevant electrode architectures and fabrication routes.