STABLE CONDUTING POLYMER ELECTROCHROMIC DEVICES INCORPORATING IONIC LIQUIDS

摘要

Electrolytes play an important role in determining the performance of conducting polymer electrochromic devices. Good electrolytes should have high conductivity, large electrochemical windows, excellent thermal and chemical stability, and negligible evaporation. Room-temperature ionic liquids are ideal electrolytes to satisfy these requirements. In the present work, we utilized ionic liquids in electrochemical synthesis of conducting polymers, in electrochemical and electrochromic characterization of both electrochemically and chemically synthesized conducting polymers, and in fabrication of conducting polymer electrochromic devices. In ionic liquids, highly stable electroactivity has been obtained for polyaniline in a wide potential range covering its entire redox process of leucoemeraldine reversible emeraldine reversible pernigraniline for > 1, 000,000 cycles. We have successfully fabricated the prototypes of alphanumeric displays and large area (5cm x 5cm) electrochromic windows. High device performance of low operation voltages (<1.5 V), high coloration contrast (> 50%), fast coloration speed (<100ms), and high columbic efficiency (> 98%), has been realized.