Electrochemical and Electrochromic Properties of All Solid-State WO3-Prussian Blue Based Electrochromic Devices

All solid-stateWO3／PrussianBlue(PB)basedelectrochromicdevices(ECDs)usingpolymeric solid electrolytes(PSEs)，which are prepare(1by dispersing homogeneously lithium trifluoromethane・ sulfonate in a hy(1rogen-bonding type intermacromolecular complex of poly(acrylic acid)and poly(ethylene oxide)，have been constructed and their electrochemical redox behaviors and electrochromic characteristics have been examined in two-electrode and three-electrode systems。The conductivity and dielectric constant of the PSEs prepared were ca．10・6S cm・1and ca．39F cm-1， respectively，at20。C，A reversible color change between blue and colorless was observed when an appropriate voltage was applied repeatedly to the WO3and PB-coated electrodes。The coloration and bleachingofthe ECD were fbund to be controlled with the electrochemical reaction ofWO3electrode whichdependsonthei司ection(and廿isintercalation)ofLi＋iQnsto(andoutQf)WO31ayer． 1 1NTRODUCTION Electrochromic displays have some remarkable characteristics，such as memory ef霊ect，color variation，good perceived contrast，10w switching voltage，10w mean power consumption and no viewing angμ1ar dependence．Thus，a variety of materials have been employed as electrochromic materials，includinginorganicmaterialssuchas WO31)，Ir(OH)x2)and Prussian Blue3)，bipyridinum compounds4)，diphthalocyanines5)and organic conducting Polymers(e．9．，poly(o-amino-pheno1)6))，Inmos七cases，however，electr㏄hromic displays have been constructed as solution_ containing system，The leakage of electrolyte solution and low stability are therefbre inevitable ＊