Evaluation of Transport Properties of Lanthanum-Based Proton-Conducting Composite Electrolytes

Abstract

Control of the transport property of proton-conducting oxides is a key issue for the development of high-performance energy conversion devices. In this study, we focus on the transport property of composites of a proton-conducing electrolyte of La2Ce2O7 (LDC) and a mixed ionic-electronic conductor of La0.3Sr0.6TiO3 (LST). The results for electrical conductivity dependences on oxygen partial pressure do not indicate the improvement of the ionic conductivity at the grain boundary resistance, while the ionic conductivity in the bulk has been improved partially. The mechanism was discussed in terms of the electronic state at LDC-LST interface or polarity at the interface.