Abstract
The ion‐conduction properties of a polyethylene oxide (PEO)‐based composite polymer electrolyte comprised of PEO, 
, and the ferroelectric material 
were studied. The addition of 
resulted in an increase in conductivity over the temperature range 25–115°C. The optimum amount of 
(purity 99.9%,particle size 0.6–1.2 μm was 1.4 wt %, which is very low in comparison with previosly reported composite polymer electrolytes. The ionic conductivity of a composite polymer electrolyte containing 1.4 wt % 
was 
at 25°C, which is at least one order of magnitude higher than that of the pristine polymer electrolyte 
. The transport number of the lithium ion in this composite polymer electrolyte was higher than that of the pristine polymer electrolyte. The increase in the conductivity and the lithium‐ion transport number is explained on the basis of the spontaneous polarization of the ferroelectric material due to its particular crytal structure. The addition of 
powder greatly enhanced the lithium/electrolyte interface stability. © 1999 The Electrochemical Society. All rights reserved.