Polymer Electrolyte-Based Cellulose Acetate for Electrochromic Polymer Device

C. Chotsuwan, A. Ngamaroonchote
National Science and Technology Development Agency, TH

Keywords: cellulose acetate, polymer electrolyte, electrochromic device

Summary:

Polymer electrolytes based on cellulose acetate have been developed as an ecologically friendly, biodegradable, and economically viable electrolyte medium substitute for existing synthetic polymer electrolytes. Cellulose acetate has promising properties as an electrolyte due to its good chemical stability, high transparency and lower crystallinity when compared to cellulose. The current study investigated the performance of polymer electrolytes based on cellulose acetate in an electrochromic device application. Cellulose acetate was used as the polymer matrix with lithium perchlorate dispersed evenly throughout. The concentration of cellulose acetate was varied from 1.5 – 9.0 wt% using propylene carbonate as a plasticizer. The ionic conductivity of the polymer electrolyte mixture was in between 1.5 – 9.0 mS/cm comparing to gel polymer electrolytes such as poly(ethylene oxide),poly(vinyl chloride), and poly(methyl methacrylate) based with an ionic conductivity of over 1 mS/cm. Then, the performance of a polymer electrochromic device with alkyl-polythiophene thin films coated onto an ITO substrate was evaluated for each mixture of the polymer electrolyte. The switching time of the devices incorporating the polymer electrolytes was 5 sec with the number of switching cycles over 5000 times.