Chemical stability enhancement of lithium conducting solid electrolyte plates using sputtered LiPON thin films

Sputter deposition of LiPON films directly onto high Li+ conductivity solid electrolyte plates has been investigated as a means to minimize the reactivity of the plates to metallic Li. The LiPON films were shown to effectively passivate the plates in contact with metallic Li, in contrast to unpassivated plates that reacted immediately in contact with Li metal. The conductivity of the passivated solid electrolyte plates was measured to be 1.0 × 10−4 S cm−1, with Arrhenius activation energy of 0.36 eV and an electrochemical stability window of at least 0–5.0V versus Li/Li+. The passivated solid electrolyte was capable of supporting electrochemical plating and stripping of Li metal, as demonstrated by EIS and CV measurements. These high chemical stability, high Li+ conductivity solid electrolyte plates will be useful for solid-state batteries employing Li anodes.