Investigation of Na_2CO_3-ABO_3 (A = Li/K/Ba and B = Nb/Ti) heterogeneous solid electrolyte systems for electrochemical CO2 gas sensor application

摘要

The ionic conductivity of Na_2CO_3:ABO_3 (where A = Li/K/Ba and B = Nb/Ti) heterogeneous solid electrolyte systems is investigated using the complex impedance spectroscopy. Presence of two depressed semicircular arcs in the complex impedance plane is accounted for the difference in defect concentration and mobility of ion in homo- and hetero-junctions. The enhancement in conductivity is understood to be due to the formation of a space charge layer across the hetero-junction. The optimised composition (30 wt.% LiNbO_3 dispersed Na_2CO_3) is found promising for CO_x electrochemical gas sensor application.