Solid State Ionics, Vol.293, 13-17, 2016
Gel polymer electrolytes based on poly(methacrylamide) derivative having branched pendant with terminal nitrile groups
We prepared new gel polymer electrolytes composed of a poly(methacrylamide) derivative having tri(cyanoethoxymethyl) group (PMCA), poly(ethylene glycol)dimetharylate (PGM400), lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) and propylene carbonate (PC). The gel polymer electrolytes were prepared by photo-initiated radical polymerization using 2-benzoyl-2-propanol as an initiator. The highest ionic conductivity for the obtained gel polymer electrolytes was 0.38 mS cm(-1) at 293 K and 2.46 mS cm(-1) at 343 K. Analysis of IR spectra of the gel electrolyte films suggested that lithium ions interacted with both nitrile groups in PMCA and carbonate groups in PC at higher lithium salt concentration. In contrast, lithium ion was solvated preferentially by the nitrile groups of PMCA at lower lithium salt concentration even in the presence of PC. The gel polymer electrolytes showed oxidation stability up to ca. 4.6 V against a lithium electrode. Reversible plating and stripping responses of lithium on a nickel electrode in the gel polymer electrolytes were also,confirmed by cyclic voltammetry. (C) 2016 Elsevier B.V. All rights reserved.