Hybrid electrolytes produced by the sot-gel process were obtained by doping a di-urea cross-linked POE/siloxane hybrid host framework (d-U(2000)) with lithium hexafluoroantimonate (LiSbF6). Flexible, transparent xerogel films with infinity>n >= 2.5 (where n, composition, represents the molar ratio of oxyethylene units OCH2CH2 per Li+ ion), thermally stable to at least 200 degrees C, were prepared. At 30 degrees C the highest ionic conductivity of all the electrolytes prepared was 1.32 x 10(-5)s cm(-1) for n = 30. The electrochemical stability windows of these materials span at least 6.0 V. Samples with n<200 are amorphous. homogeneous and non-porous. Crystallites of POE are formed in the most dilute electrolyte (n = 200). The guest Li+ ions were shown to coordinate to the oxygen atoms of the urea carbonyl groups over the entire range of salt concentration. The great majority of the SbF6- ions interact with the Li+ ions. Contact ion pairs were detected only at n = 200. Trace amounts of "free" anions exist in all electrolyte samples. (C) 2012 Elsevier B.V. All rights reserved.