The gel-forming polymer of different thicknesses was coated on both sides of polyethylene separator. The porous polymer coated on the separator was gelled by soaking in an electrolyte solution and encapsulated a larger amount of electrolyte solution. Adhesive gel formed on both sides of PE separator provided an efficient transport of lithium ion through the solid electrolyte interphase, and the electrolyte solution absorbed in the separator gave an acceptable ionic conductivity. By using the separators with adhesive gel layer, lithium metal polymer cells composed of a lithium anode and LiCoO2 cathode were assembled and their cycling performances were evaluated. The effect of thickness of gel polymer layer on cycling performances of the rechargeable lithium-metal polymer cells was investigated. (C) 2004 Published by Elsevier B.V.