Poly(ethylene oxide) (PEO) hybrids having charged ends provide a highly ion-conductive matrix. Linear- and network-type hybrid polymers with PEO/sulfonamide (SA) salt units were synthesized by the interfacial polycondensation of diamino-PEO and either 1,3-benzenesulfonyl chloride or naphthalene-1,3,6-trisulfonyl chloride. These hybrid polymers were produced as homogeneous rubbery solids showing an amorphous phase only. The bulk ionic conductivity of the resulting polymerized hybrid was large, and was similar to the value for the corresponding hybrid oligomer. In particular, the network polymer hybrid of PEO with average molecular weight of 1000 having SA Li salt ends was produced as a self-standing amorphous film. Its ionic conductivity was 2.0 x 10(-6) S cm(-1) at 50 degrees C. This value is attributable to the low glass transition temperature and the high deg;ree of dissociation of sulfonamide salts. This network polymer was confirmed to have cation conducting characteristics, since a constant current was observed in de polarization studies with lithium metal as an active electrode.