Solid Electrolyte CO[sub 2] Sensor with Lithium-Ion Conductor and Li Transition Metal Complex Oxide as Solid Reference Electrode

Solid-state sensors comprising conducting glass ceramics/ have been developed, where acts as a lithium-ion conductor and a sensing electrode material, with the two-phase mixture as the reference electrode. The electromotive force (emf) of the sensor responded well to changes of concentration at temperatures around 500°C, while it is independent of the oxygen partial pressure. Its long-term stability is good; the emf of the sensor was reproducible within mV over than 1 year in an environment of 95% humidity. This result shows that the developed sensors have high humidity resistance and good stability. The sensing mechanism is also discussed. © 2001 The Electrochemical Society. All rights reserved.