Solvent-Free Composite PEO-Ceramic FiberÕMat Electrolytes for Lithium Secondary Cells

Solvent-free composite poly~ethylene oxide! ~PEO!-ceramic fiber or mat electrolytes with high ionic conductivity and good interfacial stability have been developed using high-ionic-conductivity La0.55Li0.35TiO3 fibers and mats. The conducting ceramic fibers can penetrate the cross section of the electrolyte film to provide long-range lithium-ion transfer channels, thus producing composite electrolytes with high conductivity. In this work, a maximum room-temperature conductivity of 5.0 3 10 S cm was achieved for 20 wt % La0.55Li0.35TiO3 fiber in a PEO-LiN~SO2CF2CF3)2 mixture containing 12.5 wt % Li 1 in PEO. The maximum transference number obtained was 0.7. The ceramic fibers in this composite electrolyte are coated by a very thin PEO layer, which is sufficient to provide good interfacial stability with lithium-ion and lithium-metal anodes. © 2004 The Electrochemical Society. @DOI: 10.1149/1.1828952# All rights reserved.