Failure Mechanism of Ag/AgCl Reference Electrode Due to Current Leakage

A Ag/AgCl reference electrode was prepared by thermal-dip coating followed by electrochemical reduction. The failure mechanism of the electrode was studied by accelerated polarization method. The microstructure and performance of the electrode were analyzed by scanning electron microscopy(SEM), energy dispersed X-ray spectroscopy(EDX), and electrochemical impedance spectroscopy(EIS). After the acceleration test, the potential of the Ag/AgCl reference electrode fluctuated grjeatly, and the electrode surface showed a morphology of porous structure. EDX results indicate that AgCl transformed into Ag completely on the electrode surface. So, the failure of Ag/AgCl reference electrode could be attributed to the complete transformation of AgCl into Ag.