October 2016

In view of the fact that the establishment of alternative energy sources is coupled to the storage of the so generated energy different concepts of stationary energy storage are being investigated at the moment. Besides conventional battery systems like lithium-ion batteries alternative storage solutions that are based on abundant and cost efficient materials enter the limelight. For example several organic molecules that can be obtained by many kinds of resources can be optimized for their application in electrochemical cells. The desired molecules for this application are being defined within the scope of a collaboration between the Physical-Chemical- and the Organic Institute of the Justus-Liebig University by the investigation of the correlation between their structure and electrochemical properties. One important way to have an influence on these properties is to vary the pH value of the electrolyte the electrochemically active species is dissolved in. By modifying it the potential of the electron transfer can be varied to optimize the compound for the application in different environments. The image shows the influence of the pH value on the compounds charge transfer characteristic by shifting its potential. This is illustrated by cyclic voltammogramms that have been measured versus a Ag/AgCl reference electrode within a three-electrode assembly. (Picture submitted by Jonas Hofmann.)