Solid-state single-ion conducting comb-like siloxane copolymer electrolyte with improved conductivity and electrochemical window for lithium batteries

Achievement of high conductivity and electrochemical window at ambient temperature for an all-solid polymer electrolyte used in lithium ion batteries is a challenge. Here, we report the synthesis and characterization of a novel solid-state single-ion electrolytes based on comb-like siloxane copolymer with pendant lithium 4-styrenesulfonyl (perfluorobutylsulfonyl) imide and poly(ethylene glycol). The highly delocalized anionic charges of -SO2-A((-))-C4F9 have a weak association with lithium ions, resulting in the increase of mobile lithium ions number. The designed polymer electrolytes possess ultra-low glass transition temperature in the range from -73 to -54 degrees C due to the special flexible polysiloxane. Promising electrochemical properties have been obtained, including a remarkably high conductivity of 3.7 x 10(-5) S/cm and electrochemical window of 5.2 V (vs. Li+/Li) at room temperature. A high lithium ion transference number of 0.80, and good compatibility with anode were also observed. These prominent characteristics endow the polymer electrolyte a potential for the application in high safety lithium ion batteries. (C) 2017 Wiley Periodicals, Inc.