One important component of every electrochemical cell is the electrolyte solution. A measure for the ability of an electrolyte solution to conduct electrical current is its conductivity σelectrolyte. The conductivity can be measured by alternating current (ac) or direct current (dc) techniques. In case of ac measurements, electrochemical impedance spectroscopy is often applied.
The electrochemical test cells (“conductivity cells”) that are used for these measurements have to be calibrated initially using a calibration standard which is typically an aqueous potassium chloride solution. The result of that calibration is the so-called cell constant Kcell which has the unit [1/cm]. The cell constant can be used to calculate the conductivity from bulk resistance values determined for other electrolyte solutions of unknown conductivity.
In this application note, we demonstrate how to determine Kcell for the test cell TSC 1600 closed GC which has been developed by rhd instruments GmbH & Co. KG for the determination of the conductivity of electrolyte solutions that are sensitive towards humidity and oxygen like lithium ion battery electrolytes.
To cite this application note, please use: “Drüschler et al., rhd instruments GmbH & Co. KG, Application Note: Determination of the cell constant for conductivity measurements, April 2022”.