Structure and ionic conductivity of ionic liquid embedded PEO- LiCF3SO3 polymer electrolyte

• Main Authors: A. Karmakar, A. Ghosh
• Format: Article
• Language: English
• Published: AIP Publishing LLC 2014-08-01
• Series: AIP Advances
• Online Access: http://dx.doi.org/10.1063/1.4892855

In this paper we have reported electrical and other physical properties of polyethylene oxide (PEO) - LiCF3SO3 polymer electrolytes embedded with 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid. The addition of the ionic liquid to PEO- LiCF3SO3 electrolyte increases the amorphous phase content considerably and decreases the glass transition temperature. The relative amounts of different ionic species present in these electrolytes have been determined. It is observed that the fraction of free anions increase with the increase of ionic liquid concentration, whereas the fraction for ion pairs and aggregates show a decreasing trend under the same condition. The ionic conductivity of the PEO- LiCF3SO3 polymer electrolyte embedded with ionic liquid is higher than that of the PEO- LiCF3SO3 electrolyte. The ionic conductivity shows a transition around 323 K. The ionic conductivity above 323 K exhibits Arrhenius behavior with an activation energy, which decreases with the increase of ionic liquid concentration. However, below 323 K the conductivity shows Vogel–Tamman–Fulcher (VTF) type behavior.