Impedance Characterization of Li Ion Transport at the Interface between Laminated Ceramic and Polymeric Electrolytes

Large, dominating resistances to lithium transport at interfaces between polymeric and ceramic electrolytes is a significant limitation that must be resolved for the development of composite solid electrolytes. Laminated bilayers of lithium ion conducting glass ceramics and polymer electrolytes were studied in order to provide well-defined interfaces for the quantification of interfacial resistances. A completely dry fabrication protocol was developed to ensure intimate contact between the two phases. Interfacial resistances were then characterized by impedance spectroscopy, which revealed small, statistically significant resistances above the melting temperatures of the polymer electrolytes. These interfacial processes did not dominate the overall resistive response, representing a significant improvement over previous observations. Characterization of the laminated electrolytes by scanning electron microscopy (SEM) revealed intimate interfacial contact between the phases, and energy dispersive X-ray spectroscopy (EDS) confirmed the absence of significant compositional deviations at the interfaces.