One of the most important problems in utilizing lithium metal anodes is its poor recharge-ability due to the unstable solid electrolyte layer formed by electrolyte decomposition. To overcome this problem, the surface of the lithium electrode is covered by a thin protective solid electrolyte layer, deposited by r.f. magnetron sputtering. Lithium phosphorous oxynitride (LiPON), which is used as an electrolyte in thin film batteries (TFBs), was examined for its potential in use as a protective layer for the anode. The spectroscopic and electrochemical characteristics of the UPON layer were examined using scanning electron microscopy (SEM), Xray diffraction (XRD), linear sweep voltammetry (LSV), cyclic voltammetry (CV), chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS). (C) 2003 Elsevier B.V. All rights reserved.