Various epoxy-based networked polymers having trimethylammonium bis(trifluoromethanesulfonyl)imide groups on the network were synthesized by heating a mixture of diepoxide, glycidyl trimethylammonium bis(trifluoromethanesulfonyl)imide (GTMATFSI), and diamine curing reagent. Ethylene glycol diglycidyl ether (EGGE), poly(ethylene glycol) diglycidyl ether (PEGGE), and poly(propylene glycol) diglycidy ether (PPOGE) were used as diepoxides, and ethylene glycol bis(3-aminopropy) ether (EGBA), poly(ethylene glycol) diglycidyl ether bis(3-aminopropyl ether) (PEGBA), and polypropylene glycol bis(2-aminopropyl ether) (PPOBA) were used as diamine curing reagents. The obtained networked polymers having quaternary ammonium structure showed high thermal stability, low crystallinity, low glass transition temperature, and good ionic conductivity. In particular the networked polymers consisting or poly (ethylene glycol) segments showed high ionic conductivity (>1.0 x 10(-3) S/m) Lit room temperature.