The modification and properties of graphite felt electrodes

Monday, October 30, 2017 - 14:00
Dissertation Defence Hall (K. Donelaičio St. 73- 403 room)

Author, Institution: Brigita Macijauskienė, Kaunas University of Technology

Science Area, Field of Science: Technological Sciences, Chemical Engineering – 05T

Summary of the Doctoral Thesis: Summary

Scientific supervisor: Assoc. Prof. Dr. Egidijus GRIŠKONIS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T).

Dissertation Defence Board of Chemical Engineering Science Field:
Prof. Dr. Raimundas ŠIAUČIŪNAS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T) – chairman;
Prof. Dr. Kęstutis BALTAKYS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T);
Prof. Dr. Habil. Eugenijus NORKUS (Center for Physical Sciences and Technology, Physical Sciences, Chemistry – 03P);
Assoc. Prof. Dr. Jolanta ROUSSEAU (Artois University, France, Technological Sciences, Chemical Engineering – 05T);
Prof. Dr. Virgilijus VALEIKA (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T).

The doctoral dissertation is available on the internet and at the library of Kaunas University of Technology (K. Donelaičio g. 20,Kaunas)

Annotation:
Recently, fundamental investigations of various carbon-based materials have been conducted in search of the application for these materials in different fields. One of these carbon-based materials is graphite felt which is produced from polyacrylonitrile fiber and is light-weight, has a large specific surface area, is permeable to gas and liquids in all directions, chemically and thermally stable, and electrically conductive. Due to these properties, it can be used for the production of electrodes for various electrochemical devices. In order to make the graphite felt electrodes suitable for conduction of electrochemical processes, they are often additionally treated thermally and modified with functional substances by using chemical and electrochemical methods.
Aim of the work - to investigate the potential of graphite felt modification with Co, Co-Ni, Ni, and Ag by electroless deposition and to evaluate the electrochemical properties of the modified graphite felt with the aim to use it in the electrochemical polysulfide and bromide/bromobromide flow energy storage devices for the more effective conduction of oxidation-reduction reactions.
The modification of graphite felt with Co, Co-Ni, Ni, and Ag coatings by using the electroless (chemical) deposition method with stirring of solutions with a magnetic stirrer, ultrasound stirring (ultrasonication), and continuous circulation in flow-through reactor was investigated. The influence of different hydrodynamic conditions on the distribution of metals in the whole volume of the modified graphite felt was determined. The electrochemical properties of electrodes from graphite felt‘s modified with the respective metals in aqueous solutions of polysulphides and bromide/bromobromide were determined.