Stability of battery materials – real time monitoring of metal dissolution
Lithium ion batteries are widely used in the field of portable devices, however, they still face performance barriers like short lifetime. This is influenced by various degradation processes of materials in the battery cell. Degradation effects include structural disordering, electrolyte decomposition, gas evolution, particle cracking, aluminium and copper corrosion, dendrite formation as well as dissolution of active cathode materials. Thereby, especially the latter is known to cause severe capacity fading in cells with lithium transition metal oxide cathodes. However, the mechanism underlying the dissolution processes in various cathode materials is not fully understood. For an effective prevention of this degradation effect thorough knowledge of the processes is essential. In order to obtain new insights, we monitor the dissolution of metals from cathode materials during single charge- and discharge cycles of lithium-ion batteries in real time, obtaining potential and time resolved dependencies of dissolution processes.
Stability of electrocatalysts in nonaqueous media
The applications of nonaqueous electrochemistry are manifold and are especially relevant for energy storage and conversion devices, as well as organic electrosynthesis. Capacitors, sensors, batteries or electrochemical reactors are often operated in pure organic media or mixed electrolytes. Performing electrochemical reactions in nonaqueous media has some significant advantages over aqueous systems, one of which is the wide electrochemical window of many organic solvents compared to water. Even though electrochemistry in nonaqueous media has wide applications, the electrocatalytical processes that occur are not well understood. Our goal is to investigate the stability through dissolution profiles of different electrode materials in nonaqueous electrolytes under strictly controlled conditions to gain insight in the complex reaction mechanisms that take place at the electrode surface.
Electrochemical conversion of electric power to valuable chemicals
Electrochemistry is the marriage of electricity and chemistry. Therefore, it is natural that in the solution of problems how to convert electricity into chemicals electrochemistry stays in the foreground. Organic electrochemistry already enjoys popularity, however, in this discipline electrochemistry is mainly used as a tool and less attention is paid for the underlying processes. Since these processes are very complicated it is not easy to understand what is happening at the electrodes. Our aim is to understand basic electrocatalytic phenomena in order to be able to better control targeted synthesis reactions and easier find their optimum conditions.