Effect of thickness of coating layer on polymer-coated separator on cycling performance of lithium-ion polymer cells

Porous polymer-coated separators with different thicknesses of coating layer have been prepared by a dip coating and phase inversion method. Polymer-coated separators soaked with electrolyte solution exhibit high ionic conductivity in the order of 10(-3) S cm(-1) at room temperature and are electrochemically stable up to 5.0 V against Li+/Li. Lithium-ion polymer cells each composed of a mesocarbon microbead anode and a lithium-cobalt oxide cathode and separated with a polymer-coated separator, have been assembled and their charge-discharge cycling performance has been evaluated in terms of the thickness of the gelled polymer layer that is coated on the polyolefin separator. (C) 2003 Elsevier B.V. All rights reserved.