Preparation and in-situ characterization of well-defined solid electrolyte/electrode interfaces in thin-film lithium batteries

An all-in-vacuum (in-vacuo) fabrication and evaluation system for thin-film all-solid-state lithium batteries was designed and constructed. To prepare clean solid electrolyte/electrode interfaces, ultra-high-vacuum (UHV) chambers for the deposition of cathode, electrolyte, and anode thin films were directly connected to each other. Thus, throughout the fabrication and evaluation, the samples were maintained under UHV conditions, not exposed to air. The thin-film lithium battery, with a clean and well-defined solid electrolyte/electrode interface, exhibited very good electrochemical properties even without post-deposition annealing. This performance is attributed to the clean solid electrolyte/electrode interface prepared in the vacuum.