Development of manganese-based thin-film probe via hydrothermal process for localized electrochemical impedance analysis of a solid-state electrolyte LiPON

A facile low-temperature synthesis process, including the first electrodeposition and the second hydrothermal reaction, has been adopted in fabricating the Li-Mn-O thin-film probe to measure the localized electrochemical impedance of the solid-state electrolyte LiPON. The synthesized thin film is uniformly and densely deposited on the probe, which is composed of layered Li₂MnO₃ and LiMnO₂ crystalline phases. In addition to surface topography mapping, using the thin-film probe allows us to discern the dominant charge transfer resistance at the LiPON/Li-Mn-O interface from the electrolyte resistance in nanoscale level, which is different from the results obtained by a conductive probe as well as a MIM cell. It is also found by the thin-film probe that the ion transport in LiPON and charge transfer behavior at the LiPON/Li-Mn-O interface can be facilitated by introducing an external voltage.