Responsible Person: Mariia Liseanskaia, M.Sc., Institute for Materials and X-Ray Physics

Project Topic:

This project conducts research on the interplay of fluid dynamics and electrochemistry for better understanding electrochemical processes inside nanoporous conductive materials and the impact of imbibition and evaporation on energy characteristics. Water phase transitions in nanopores can be used to generate electrical energy on a large scale. Nanoporous carbon monoliths filled with aqueous electrolytes are promising candidates for electrical energy harvesting and conversion. The reason for this is that the double electric layer and the electric current can be obtained during spontaneous imbibition and drying without an external energy source.

Supervisors:

Prof. Dr. Patrick Huber, Prof. Dr.-Ing. Irina Smirnova

Methods:

Experimental

• Dilatometry
• Gravimetry
• SAXS/WAXS
• Open-circuit methods
• Zero Resistance Amperometry

The object of the study is carbon mesoporous monoliths. They are produced by polymerization followed by carbonization and activation. Carbons are characterized with an isotropic interconnected pore network with pore size 10-12nm.

The experiments investigate the interplay of imbibition and evaporation in nanoporous carbons and electrochemical respond to these phenomena. The most pronounced behavior is the relaxation of the current flowing between the sample and the counter electrode, as well as the potential difference between them. The observed processes are also affected by ion mobility, which can be a "bottle neck" for relaxation, the creation/destruction of the electrical double layer and surface chemistry features. All these parameters should be explored for better understanding how electrical energy can be generated.