Single Lithium-Ion Conducting Polymer Electrolytes Based on a Super-Delocalized Polyanion

A novel single lithium-ion (Li-ion) conducting polymer electrolyte is presented that is composed of the lithium salt of a polyanion, poly[(4-styrenesulfonyl) (trifluoromethyl ( S-trifluoromethylsulfonylimino) sulfonyl) imide] (PSsTFSI(-)), and high-molecular-weight poly (ethylene oxide) (PEO). The neat LiPSsTFSI ionomer displays a low glasstransition temperature (44.3 degrees C; that is, strongly plasticizing effect). The complex of LiPSsTFSI/PEO exhibits a high Li-ion transference number (t(Li)(+) = 0.91) and is thermally stable up to 300 degrees C. Meanwhile, it exhibits a Li-ion conductivity as high as 1.35 x 10(-4) S cm(-1) at 90 degrees C, which is comparable to that for the classic ambipolar LiTFSI/PEO SPEs at the same temperature. These outstanding properties of the LiPSsTFSI/PEO blended polymer electrolyte would make it promising as solid polymer electrolytes for Li batteries.