Effect of lithium hexafluorophosphate LiPF6 and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [Bmim][TFSI] immobilized in poly(2-hydroxyethyl methacrylate) PHEMA

Abstract

A solid polymer electrolyte of poly(2-hydroxyethyl methacrylate) PHEMA and lithium hexafluorophosphate (LiPF6) and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [Bmim][TFSI] was successfully prepared via the solution casting method. X-ray diffractometer, Fourier transformation infrared spectroscopy, scanning electron microscopy and electrochemical impedance spectroscopy were used to study the structural, optical, morphological and electrochemical properties of the prepared solid polymer electrolytes. From the results, with the addition of ionic liquid in the polymer electrolytes system improved the properties of the polymer electrolytes such as lower the crystallinity and become smooth in surface morphology, hence helps increase in ionic conductivity. High ionic conductivity exhibited at 30 wt% of 1.0 M LiPF6 (EC/DEC) (1:1) in the PHEMA with the value of 2.13 × 10−6 S cm−1. This value was increased up to one magnitude order with the addition of ionic liquid where the value is 8.01 × 10−5 S cm−1 at room temperature. This implies that these polymer electrolytes are possibly suitable for further application in low-power electrochemical devices.