Three-Electrode Reference Setup for Anode Overpotential Measurement
Three-electrode anode overpotential testing isolates uncompensated potential thresholds to prevent lithium plating during fast charge algorithm design
Three-Electrode Setup
Meaning
Electrochemical cell configurations integrate a reference electrode alongside the working and counter electrodes to measure the potential of a single interface without interference. Employing a three-electrode setup enables researchers to isolate the cathodic and anodic processes during cell operation. This separation of signals is essential for analyzing the degradation of individual active materials.
System Architecture
The working electrode and the counter electrode carry the main polarization current, while the reference electrode remains in a zero-current path. Placing the reference electrode close to the working electrode minimizes the uncompensated resistance of the electrolyte. This positioning ensures that the measured potential reflects the true interface voltage of the working electrode.
Analytical Benefit
Individual electrode kinetics and thermodynamic potentials are monitored during charging and discharging to identify the causes of cell degradation. The three-electrode setup allows researchers to determine whether capacity fade is driven by lithium inventory loss at the anode or by active material degradation at the cathode. This insight helps designers select optimal material combinations and adjust the operating voltage windows to prolong cell life.
It is also valuable for evaluating the performance of new electrolyte additives under realistic operating conditions.
Hardware Limitation
Assembly is complex because the third electrode can disrupt current distribution. Improper positioning of the reference electrode can lead to measurement errors. This requires specialized pouch cells with embedded reference wires to maintain uniform electrochemical conditions.