Structural changes in Li/LIPON/LiCoO2 thin-film lithium batteries during initial cycling were investigated. Scanning electron microscopic and Raman spectroscopic analyses indicated that initial cycling resulted in aligned nanorods of LiCoO2 and improved interfacial connection of LiCoO2-LIPON and LiCoO2-Pt current collector but local structural disordering and an increased fraction of (003)-oriented grains in originally (101)/(104)-oriented LiCoO2 film. The structural changes are attributed to irreversible initial capacity loss of 33%. The data contribute to a basic understanding of the structural factors that can affect cell resistance and cycling behavior in the operation of solid-state electrochemical systems. (c) 2008 The Electrochemical Society.