Abstract

In this study, Li₂MnSiO₄ cathode material and LiPON solid electrolyte were manufactured into thin films, and the possibility of their use in thin-film batteries was researched. When the RTP treatment was performed after Li₂MnSiO₄ cathode thin-film deposition on the SUS substrate by a sputtering method, a β-Li₂MnSiO₄ cathode thin film was successfully manufactured. The LiPON solid electrolyte was prepared by a reactive sputtering method using a Li₃PO₄ target and N₂ gas, and a homogeneous and flat thin film was deposited on a Li₂MnSiO₄ cathode thin film. In order to evaluate the electrochemical properties of the Li₂MnSiO₄ cathode thin films, coin cells using only a liquid electrolyte were prepared and the charge/discharge test was conducted. As a result, the amorphous thin film of RTP treated at 600℃ showed the highest initial discharge capacity of about 60 μAh/㎠. In cases of coin cells using liquid/solid double electrolyte, the discharge capacities of the Li₂MnSiO₄ cathode thin films were comparable to those without solid LiPON electrolyte. It was revealed that Li₂MnSiO₄ cathode thin films with LiPON solid electrolyte were applicable in thin film batteries.

• Keywords: Li₂MnSiO₄, Cathode, Thin film, Thin film battery, Sputtering