We report a polysiloxane based single-ion conducting polymer electrolyte (SIPE) synthesized via hydrosilylation technique. Styrenesulfonyl (phenylsulfonyl) imide groups were grafted on the highly flexible polysiloxane chains followed by lithiation. The highly delocalized anionic charges in the grafted moiety give rise to weak association with lithium ions in the polymer matrix, resulting in lithium ion transference number close to unity (0.89) and remarkably high ionic conductivity (7.2 ×10 -4 Scm -1 ) at room temperature. The high flexibility arising from polysiloxane enables the glass transition temperature (T g ) to be below room temperature. The electrolyte membrane displays high thermal stability and a strong mechanical strength. A coin cell assembled with the membrane comprised of the electrolyte and poly(vinylidene-fluoride-cohexafluoropropene) (PVDF-HFP) performs remarkably well over a wide range of temperature with high charge-discharge rates.12 rule in a three step cyclic process.[36] Following the same mechanism, here, the vinylic part of SPSIK was attached to the polysiloxane chains upon addition of a Si-H bond.The grafting of SPSIK on PMHS chains followed by exchange of K + ions by Li + ions was clearly proven to be successful by FTIR and NMR spectra. As can be seen in the FTIR spectra of PMHS and SG (Fig. 1), the peak at 2167 cm -1 in PMHS, corresponding to Si-H bond, is disappeared in SG, which confirms the grafting of SPSIK. In addition, the peak at 1627 cm -1 in SPSIK, corresponding to the vinylic group, is also disappeared in SG, confirming the grafting, which consumes the vinylic group. Furthermore, the signature signal of Si-H, appears at 4.68 ppm ( 1 H NMR) in PMHS, and the three peaks in the range of 6.78 to 5.31 ppm ( 1 H NMR) in SPSIK corresponding to 3 vinylic protons, are disappeared in SG, validating the grafting of SP on the PMHS chains. [43,46]. Finally, the overall synthesis of SG electrolyte was confirmed by the coherence between the expected and the found values for all the elements, except for Si, in the elemental analysis. The deviation observed for Si is mainly attributed to the incomplete digestion of Si during the analysis, which was also noticed during the elemental analysis of commercial products of Si such as PMHS and poly(methylphenylsiloxane)(PMPS) ( Table S1 in Supporting Information). The GPC analysis of SG in the tetrahydrofuran (THF) mobile phase depicts the number average molecular weight (Mn) of 84,238, weight average molecular weight (Mw) of 150,230, and poly dispersity index (PDI) of 1.78 based on the polystyrene standard.