Highly transparent sustainable biogel electrolyte based on cellulose acetate for application in electrochemical devices

• Published in: International journal of biological macromolecules Vol. 265; no. Pt 1; p. 130757
• Main Authors: Balboni, Raphael D.C., Cholant, Camila M., Lemos, Rafaela M.J., Rodrigues, Lucas S., Carreno, Neftali L.V., Santos, Marcos J.L., Avellaneda, Cesar A.O., Andreazza, Robson
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-04-2024
• Subjects: Cellulose acetate; Electrochemical device; Electrolyte; Electrolyte; Cellulose acetate; Electrochemical device
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.130757

In this study, an easy and low-cost production method for a cellulose acetate-based gel polymer containing lithium perchlorate and propylene carbonate is described, as well as the investigation of its properties for potential use as an electrolyte in electrochemical devices. Cellulose acetate, a biopolymer derived from natural matrix, is colourless and transparent, as confirmed by the UV–Vis spectroscopy, with 85 % transparency in visible spectrum. The gels were prepared and tested at different concentrations and proportions to optimise their properties. Thermogravimetry, XRD, and FTIR analyses revealed crucial characteristics, including a substantial 90 % mass loss between 150 and 250 °C, a semi-crystalline nature with complete salt dissociation within the polymer matrix, and a decrease in intensity at 1780 cm−1 with increasing Li+ ion concentration, suggesting an improvement in ionic conduction capacity. In terms of electrochemical performance, the gel containing 10 % by mass of cellulose acetate and 1.4 M of LiClO4 emerged as the most promising. It exhibited a conductivity of 2.3 × 10−4 S.cm−1 at 25 °C and 3.0 × 10−4 S.cm−1 at 80 °C. Additionally, it demonstrated an ideal shape of cyclic voltammetry curves and stability after 400 cycles, establishing its suitability as an electrolyte in electrochemical devices.