Ferroelectric materials as a ceramic filler in solid composite polyethylene oxide-based electrolytes

The electrochemical properties of mixed-phase composite electrolytes based on poly(ethylene oxide) (PEO), lithium salts (LiClO4, LiBF4, LiPF6, LiCF3SO 3, and Li[(CF3SO2)(2)N]), and ferroelectric materials (BaTiO3, PbTiO3, and LiNbO3) have been studied. The ion-conduction and lithium-ion transference numbers of the composite polymer electrolytes were enhanced by the addition of these ferroelectric materials as a ceramic filler. The conductivity beh avior of the composite electrolyte depended on the combination of lithium s alt and the ferroelectric materials. The conductivity enhancement in the PE O-LiX composite electrolytes with ferroelectric materials was rationalized by correlating the association tendency of anions with lithium cations and the spontaneous polarization of the ferroelectric ceramics due to their par ticular crystal structure. The combined addition of rutile type TiO2 and Ba TiO3 assured long-term interfacial stability. All the electrolytes studied here showed decomposition potentials higher than 4 V vs. Li/Li+ (C) 2000 Th e Electrochemical Society. S0013-4651(99)11-061-9. All rights reserved.