A high performance limiting current oxygen sensor with Ce0.8Sm0.2O1.9 electrolyte and La0.8Sr0.2Co0.8Fe0.2O3 diffusion barrier

Abstract

A dense diffusion barrier limiting current oxygen sensor with Ce0.8Sm0.2O1.9 (SDC) solid electrolyte and La0.8Sr0.2Co0.8Fe0.2O3 (LSCF) dense diffusion barrier was developed. The effects of the oxygen concentration and temperature on the limiting current were investigated and the response time of the oxygen sensor was measured. The limiting current oxygen sensor exhibits a good limiting current platform when the oxygen volume fraction is from 0 to 0.21. The limiting current linearly increases with the oxygen volume fraction. At 973K, it improves from 40 to 120mA as the oxygen volume fraction increases from 0.038 to 0.21. In addition, the limiting current oxygen sensor shows a wide voltage platform interval, which is from ∼0.5 to ∼1.7V. The response time of the sensors is about 15–30s. The sensor continuously operated at 973K for 60h, its limmiting current is almost invariable, which is ∼30mA. These results suggest that the oxygen sensor with LSCF as a dense diffusion barrier and SDC as a solid electrolyte provides a potential approach to the performance improvement of the limiting current oxygen sensor for practice use.