Study of Capacitive Behavior and its Inter-Relationship with Electrolyte Solution Concentration in Hybrid Ionogels

Abstract

Ionogels are synthesized by confining ionic liquids within a solid/polymer matrix. Ionogels received wide attention owing to their high ionic conductivity and mechanical properties. Recent research has revolved around augmenting the ionic conductivity and mechanical stability of ionogel. Nevertheless, a detailed understanding of the inherent capacitive behavior is indispensable to ensure the application of ionogels in rechargeable lithium-ion batteries, sensors, and supercapacitors. Even though studies on the cyclic voltammetry of ionogels have been previously established, there are limited studies on evaluating the specific capacitance of ionogel, with respect to the amount of electrolyte solution present in the ionogel system. In this study, the ionogel is fabricated through sol-gel route, and the charge storage capacity of ionogel is investigated with varying concentrations of electrolyte solution. Electrochemical Methods such as Linear Sweep Voltammetry (LSV) and cyclic voltammetry (CV) are used to characterize the electrochemical performance of ionogel. The most effective concentration of electrolyte solution is determined to be 30 vol% in this study and has attained high electrochemical stability, up to 3.2 V. The ionogel has excellent charge-discharge characteristics, with a specific capacitance of ∼18.90 F g−1. Meanwhile, the ionogel also exhibits good thermal stability, 358 °C. The combination of promising electrochemical properties and thermal sability allows the practical application of ionogel.