Abstract
Interfacial ionic conduction has been considered to play an important role in composite electrolyte of solid oxide fuel cell (SOFC). However, the contribution of interfacial conduction has not been well evaluated. In this study, interfacial conduction is evaluated in a composite electrolyte composed of (Na0.57K0.43)0.94Li0.06NbO3 (KNN) with ignorable electrical conductivity and ZnO with low bulk ionic conductivity. The dependence of power output on the ratio of KNN and ZnO as well as the size of particles is investigated to understand the influence of interfacial areas on cell performance. Additionally, the issues affecting cell performance is analyzed from the view of electric circuit model by focusing on the electrical property. A method is proposed to indirectly evaluate the existence of charge carriers at the interfaces. Moreover, the segregation of K at the interfaces of KNN and ZnO is confirmed, which is believed to play an important role in forming space charge layers at the interfaces and trigger the formation of high concentration of oxygen vacancies for improving interfacial ionic transportation. This study uncovers that element segregation at the interface of two phases maybe an important issue for ionic transportation at the hetero-interface of composite electrolyte for fuel cell application.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call