In this work, innovative proton exchange membranes containing dicationic ionic liquids are developed for elevated temperature fuel cells applications under anhydrous conditions. The composite membranes based on polybenzimidazole (PBI) and dicationic ionic liquid 1,6-di(3-methylimidazolium) hexane bis (hexafluorophosphate) (PDC6) or monocationic ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate (PMC4) are prepared with solution casting method. The analyses of the results demonstrate promising characteristics such as high ionic conductivity and fuel cell performance of phosphoric acid (PA) doped PDC6 composite membranes in comparison with PA doped PMC4 and PA doped PBI membranes at high temperatures. Dicationic ionic liquid with high number of charge carriers provides suitable ionic channels for proton transfer in PA doped PDC6 composite membranes. The ionic conductivity of 78 mS cm(-1) and power density of 0.40 W cm(-2) (at 0.5 V) are achieved for PA doped PDC6 composite membranes with PBI/ionic liquid mole ratio: 4 at 180 degrees C under anhydrous condition. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.