Nonflammable and thermally stable gel polymer electrolytes based on crosslinked perfluoropolyether (PFPE) network for lithium battery applications

摘要

A gel polymer electrolyte (FGPE) based on a perfluoropolyether (PFPE) crosslinker and liquid state PFPE doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is prepared, and its characteristics including ionic conductivities, Li+ transference numbers, and thermal/electrochemical stabilities are investigated. A commercial PFPE-dimethacrylate, Fluorolink MD700 (R), is found to be a suitable crosslinker for the FGPE preparation due to its good miscibility with the PFPE/LiTFSI electrolytes. The ionic conductivity and Li+ transference number of the FGPE at 60 degrees C are 1.72 x 10(-5) S cm(-1), and 0.53, respectively. The FGPE is nonflammable, thermally stable up to 175 degrees C without any weight loss, and has a wide electrochemical stability window (similar to 5.0V vs. Li/Li+). Therefore, the FGPE is expected to be a promising electrolyte candidate for safety-reinforced high-temperature lithium batteries. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.