Electronic structures of Li+ ion-ethylene carbonate (EC) complexes were studied by density functional theory. The structural, electronic and dynamical properties of Li+-EC complexes were studied for both an isolated EC molecule and clusters including Li+ ion. Our structural analysis showed only one type of Li+ coordination with EC through Li+center dot center dot center dot O=C which was supported by the vibration spectral analysis for interaction between Li+ ion and a solvent (EC) molecule. It was analyzed that the solvation energy and Mulliken charge of Li+ ion solvated by EC molecule decrease with increase in number of EC molecule. However, electron affinity shows the opposite change. This analysis with solvation energy, electron affinity and Mulliken charge supported the stabilization of 4-coordinated solvation shell among [Li+(EC)(n)](n=1-5) complexes. (C) 2010 Elsevier B.V. All rights reserved.