Effect of alkyl-chain length of imidazolium based ionic liquid on ion conducting and interfacial properties of organic electrolytes

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 26; pp. 136 - 142
• Main Authors: Kim, Kyungmin, Kim, Seok
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.06.2015; 한국공업화학회
• Subjects: Chain length; Interface; Ion conducting; Ionic liquids; Organic electrolytes; 화학공학; Ionic liquids; Organic electrolytes; Ion conducting; Chain length; Interface
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2014.11.025

The effect of imidazolium ionic liquid with a different alkyl side chain (ethyl, propyl and butyl) on ion conducting and interfacial properties of organic electrolytes against carbon electrode was studied. Among the ionic liquids, BMImBF4 (10vol.%)—containing electrolyte presented the maximum specific capacitance (130.5Fg−1), capacitance retention (close to 80% after 1000 cycles) and low interfacial resistance of between electrolyte and electrode. •Organic electrolytes were prepared using imidazolium ionic liquids with a different alkyl-chain length.•Ion conducting and interfacial properties of organic electrolytes against carbon electrode were studied.•Modified electrolytes showed the improved electrochemical performances such as high capacitance and low interfacial resistance. In this study the effect of imidazolium ionic liquid with a different alkyl side chain (ethyl, propyl and butyl) on ion conducting and interfacial properties of organic electrolytes against carbon electrode has been invested. The influence of electrochemical performances of imidazolium ionic liquids additives into organic solvent were examined by linear sweep voltammetry (LSV) cyclic voltammetry (CV), galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS). The imidazolium ionic liquids with ethyl, propyl and butyl chains exhibited a variant electrochemical performance such an improved specific capacitance, low resistance, good rate capability and excellent cycle ability. Among the ionic liquids, BMImBF4 (10vol.%)—containing electrolyte presented the maximum specific capacitance (130.5Fg−1), capacitance retention (close to 80% after 1000 cycles) and low interfacial resistance of between electrolyte and electrode. It means that 10% BMImBF4 in EC/DME (1/1) can be a proper electrolyte of capacitors.