Abstract: The interface between solid electrolyte and alkali-metal electrodes is critically important to the performance of a range of electrochemical devices including solid-state batteries. Inhomogeneous solid-electrolyte interfaces can lead to dendrite formation and high interfacial resistance. In the present invention, the interaction between an alkali metal and ceramic solid-electrolyte is enhanced through the in-situ decoration of the solid-electrolyte free surface with metal nanoparticles. The metal nanoparticles are exsolved from metal oxide dopants during the high temperature processing of solid electrolyte membranes.