Modified Transport Properties Of LiNbO3 Dispersed Li2CO3 Composite System For Electrochemical CO2 Sensor

¹Dharampeth M P Deo Memorial. Science College, Nagpur 44 00 33, India

²Department of Physics, Govt. College of Engineering, Amravati 44 46 04, India

³Department of Physics, RTM Nagpur University, Nagpur 44 00 33, Indi

Adv. Mater. Lett., 2014, 5 (2), pp 75-79

DOI: 10.5185/amlett.2013.fdm.20

Publication Date (Web): Jan 27, 2014

Copyright © IAAM-VBRI Press

E-mail: pacific0701@gmail.com

Abstract

In the present investigation, LiNbO₃ dispersed Li2CO₃ composite of varying volume fraction is prepared. Its validity of placement in ionic conductor is verified by determining ionic transference number by Wagner’s dc polarization technique and bulk electrical conductivity is estimated with complex impedance spectroscopy. Two different conduction mechanisms are revealed by the complex impedance plots at low and high frequencies. Significant enhancement in the ionic conductivity has resulted due to enhancement in vacancies at the grain boundary interface facilitated by the localized polarization of carbonate grains due to the presence of ferroelectric phase. The effect on electrode kinetics is studied by characterizing an electrochemical CO₂ gas sensor with this composite as sensing electrode which showed significant reduction in response time and recovery time (<10 sec). The use of such composite systems will benefit the development of fast electrochemical devices.

Keywords

Composite solid electrolyte, impedance spectroscopy, transport number, electrochemical gas sensor.