Solid Electrolyte CO2 Sensor Using NASICON and Li-based Binary Carbonate Electrode

Abstract

Abstract A solid electrolyte CO2 sensor was developed by combining an Na+ conductor and a Li-based binary carbonate auxiliary electrode represented by Li2CO3–CaCO3 (1.8 : 1 in molar ratio: eutectic mixture). It responded to CO2 quickly and reversibly, following a Nernst equation excellently in the CO2 concentration range 102–105 ppm. In addition, Li2CO3–CaCO3 electrode was found to be stable to deliquescence even when kept under a highly humid condition at 30 °C for more than 700 h.