Patent ID: 7399791

Claim:
A method of using a membrane in fuel cell applications, comprising the step of providing an ionomeric membrane made of (per)fluorinated, semicrystalline or amorphous, ionomeric polymers, having equivalent weight (EW) from 380 g/eq to 1,800 g/eq, when used in a fuel cell under the following conditions: 50 μm membrane thickness assembled between two electrodes catalyzed with 0.6 mg/cm 2 Pt supported on Carbon (Pt/C) and treated with 0.7 mg/cm 2 of perfluorinated polymer, having 10cm 2 area; hydrogen and air feeding, both at the pressure of 0.25 MPa, both saturated with water at 80° C.; cell temperature 75° C.; and is formed of copolymers of TFE/F 2 C═CF—O—(CF 2 ) 2 —SO 2 F, gives the following maximum specific power values (P MAX ), at the indicated EW values: EW = 670 P MAX higher than 0.55 Watt/cm 2 ; EW = 830 P MAX higher than 0.66 Watt/cm 2 ; EW = 1,160 P MAX higher than 0.50 Watt/cm 2 ; EW = 1,600 P MAX higher than 0.32 Watt/cm 2 .