Electrochemical impedance analysis on solid electrolyte oxygen sensor with gas and liquid reference electrodes for liquid LBE

Abstract

The ionic conductivity of solid electrolyte may insufficient, and the sensor output signal will deviate from the theoretical one in low temperature. The performance of oxygen sensor with Ag/air reference electrode (RE) and liquid Bi/Bi2O3 RE was tested in low-temperature LBE at 300°– 450°C and the charge transfer reactions impedance at the electrode-electrolyte interface was analyzed by electrochemical impedance analysis (EIS). After steady state condition, both of the sensors performed well and can be used at 300°– 450°C. Bi/Bi2O3 RE has lower impedance than Ag/air RE. Therefore, the response time of the oxygen sensor with Bi/Bi2O3 RE is faster than the oxygen sensor with Ag/air RE in the low-temperature region.