Phases, Structures, and Electrical Properties of Li-Doped LaNbO4 Materials

Acceptor-doped LaNbO4 is well documented to be a promising proton conductor. However, the relatively low proton conductivity limits its widely application, although many dopants are applied to overcome this shortcoming. Herein, a series of Li-doped La1-x Li x NbO4-x materials are prepared via a traditional solid-state reaction method, with their phases, structures, and electrical properties being studied thoroughly. The results reveal an extremely low solubility for Li at the La site, which can be rationalized by the high endothermic solution energy of approximate to 7.57 eV calculated by the atomistic-static-lattice simulation method. Thus, all the prepared single-phase samples (0 <= x <= 0.3) show similar chemical compositions, crystal structures, and electrical properties.

Automated summary

Accepter-doped LaNbO4 is a promising proton conductor, but its low proton conductivity hinders its widespread application. In this study, Li-doped La1-x Li x NbO4-x materials were prepared and studied, revealing a low solubility for Li at the La site.