Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsberg reaction. Since the bis(sulfonyl)imide anion is immobilized in the polymer chain, the lithium cation transference number was measured to be 0.87. The weight average number molecular weight (M-w) was found to be 105,343 determined by gel permeation chromatography (GPC). A gel polymer electrolyte membrane, comprising of PVDF and PSSPSI, was successfully prepared with the ionic conductivity of 1.1 x 10(-3) S cm(-1) at room temperature. The membrane exhibits a wide electrochemical window up to 4.5 V (vs. Li+/Li) and is thermally and mechanically stable. The material is well suited for applications in lithium-ion batteries. (C) 2014 Elsevier B.V. All rights reserved.