A cathode was prepared by sealing a carbon supported sulfur electrode inside a composite ion-selective net made of carbon, binder and lithiated ionomer to restrict shuttling of polysulfide anionic species. As a result, the soluble polysulfide anions become unable to escape from the composite ion-selective films due to the electrostatic repulsion between the immobilized single ion conducting ionomers and the polysulfides with no dead angles. Experimentally, lithiated 4,4'-difluoro bis(benzene sulfonyl)imide and PEG200 were copolymerized to form a polyether based single ion conducting polymer. The ionic conductivity of the blend film made of ionomer and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) at a mass ratio of 1:1 is 0.57 mS cm(-1) at room temperature. The battery capacity with the sealed sulfur electrode is 1412 mAh g(-1) at 0.5 C, 1041 mAh g(-1) at 1.0 C, 873 mAh g(-1) at 2.0 C and 614 mAh g(-1) at 5.0 C, significantly better than the results with lithiated Nafion especially at high C rates. In addition, a long cycling test at 2 C for 500 cycles gives rise to a stable capacity of 800 mAh g(-1). The intrinsic electrostatic repulsion between polysulfide anions and the negatively charged electrolyte film, together with the overall sealed electrode configuration, is responsible for blocking the shuttling of polysulfides effectively. (C) 2017 Elsevier B.V. All rights reserved.