Stability effect of polymer-based additives on EMITFSI-LiTFSI electrolyte in lithium-air battery

Abstract

Electrolytes with polymer additives are reported as promising electrolyte systems that poses many advantages over nonaqueous ionic liquid-based electrolytes in terms of electrochemical stability. In this study, novel 1-ethyl-3-methyl-imidazoliumbis (trifluoromethanesulfonyl)imide (EMITFSI)/lithium bis(trifluoromethanesulfonyl)imide (LITHO-based electrolytes using polyethylene oxide (PEO) and polyvinylidene fluoride (PVDF) additives were prepared and the electrochemical performances were studied. The surfaces of the cathodes were subjected to scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The as-prepared electrolytes were also subjected to cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge tests for further electrochemical analyses. One molar of EMITFSI-LiTFSI electrolyte with 0.1 wt%. PEO exhibited a low and stable electrode resistance of 47.4 Omega.cm(-2) and a specific capacity of 2.5 mAh g(-1) after 10 cycles. The improvement in the electrochemical characteristics was attributed to the positive effect of the polymer additives on the internal resistance of the cells. (C) 2015 Elsevier B.V. All rights reserved.