Chitosan-Based Polymer Electrolyte Containing an Ionic Liquid and Inorganic Salt

Abstract

: Electrochemical energy storage systems (e.g. batteries and supercapacitors) have a vital role in the applications of many portable electronics, medical equipment, electric vehicles, military devices, and renewable energy [1]. The advancements in these technologies, increase the demand for electrochemical energy systems to achieve higher levels of performance [2]. The development of these high-performance systems have proven extremely difficult because of the need to simultaneously satisfy multiple battery performance requirements such as high energy, high power, long cycle life, low-cost, wide temperature range, safety, minimal impact to the environment, and flexibility to meet various design needs [3,4].Currently, conventional electrochemical storage systems suffer from serious problems such as leakage, toxicity, and high-cost disposal, resulting in unsuitable long-term sustainability [1]. Solid polymer electrolytes have attracted considerable attention for their potential in electrochemical devices due to their light weight, thermal stability, reduced risk of leakage, and flexibility [4]. These systems are mainly comprised of a crosslinked network between a polymer, an organic liquid (e.g. ethylene carbonate, propylene carbonate, diethyl carbonate, etc.), and lithium based salt [5].In this study, a gel electrolyte consisting of the host polymer, chitosan, has been synthesized to compare the crosslinking components, acetic acid and adipic acid. The films were incorporated with an ionic liquid and inorganic salt (LiCl) to increase ionic conductivity. FT-IR plots were compared to determine possible cross-linking mechanisms. Thermal analysis and AC impedeance data were obtained to determine the effect of the crosslinker, as well as the concentration of salt on the thermal stability and ionic conductivity of the gel samples.