Patent ID: 8492050

Claim:
A Ionic Liquid Based Membrane (ILBM) for fuel cells consisting of (A) polysiloxane-based Room Temperature Vulcanized matrix having a thickness equal to or greater than 140 μm, and (B) an ionic liquid selected from BmimCF 3 SO 3 and EmimCF 3 SO 3 evenly dispersed in said matrix, said ionic liquid being formed in situ in the membrane by an ion-exchange reaction in which anion CF 3 SO 3 − replaces a cheaper anion selected from BF 4 − and Cl − , said ionic liquid and said anions being the only charge carriers in said Membrane; wherein said matrix imparts to said Membrane mechanical features comprising flexibility, strength, and ruggedness, and, entrapped but freely moving in said matrix, imparts to said Membrane high conductivity, wherein said conductivity is not dependent on the membrane water content and is maintained even after heating above 65° C. and cooling down to 25° C., said Membrane being impermeable to methanol and being chemically stable up to a temperature of 400° C. according to TGA.