Reinforced electrolyte membrane for fuel cell, fuel cell membrane-electrode assembly, and solid polymer electrolyte fuel cell comprising the fuel cell membrane-electrode assembly

• US 8,795,923 B2
• Filed: 10/17/2008
• Issued: 08/05/2014
• Est. Priority Date: 04/19/2007
• Status: Active Grant

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation), W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Akita, Yasuhiro, Nagasawa, Takeshi, Suzuki, Takeyuki, Matsuura, Toyohiro
• Primary Examiner(s): Gilliam, Barbara
• Application Number:
  US12/919,276
• Publication Number:
  US 20110008708A1
• Time in Patent Office: 2,118 Days
• Field of Search: 429479-483, 429491-496, 429/535
• US Class Current: 429/483
• CPC Class Codes: C08J 2327/18 Homopolymers or copolymers of tetrafluoroethylene
• CPC Class Codes: C08J 5/2206 based on organic and/or inorganic macromolecular compounds
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1039 halogenated, e.g. sulfonated polyvinylidene fluorides
• CPC Class Codes: H01M 8/1048 Ion-conducting additives, e.g. ion-conducting particles, heteropolyacids, metal phosphate or polybenzimidazole with phosphoric acid
• CPC Class Codes: H01M 8/106 characterised by the chemical composition of the porous support
• CPC Class Codes: H01M 8/1062 characterised by the physical properties of the porous support, e.g. its porosity or thickness
• CPC Class Codes: H01M 8/1067 characterised by their physical properties, e.g. porosity, ionic conductivity or thickness
• CPC Class Codes: H01M 8/1079 Inducing porosity into non porous precursors membranes, e.g. leaching, pore stretching
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention provides a reinforced electrolyte membrane for fuel cell comprising a porous substrate impregnated with a polyelectrolyte liquid dispersion, wherein either the maximum tensile strength in the machine direction (for sheet processing) (MD) or the maximum tensile strength in the transverse direction (TD; vertical to the MD direction) for the electrolyte membrane is 70 N/mm² or more at 23° C. at a relative humidity of 50% or 40 N/mm² or more at 80° C. at a relative humidity of 90%. This reinforced electrolyte membrane for fuel cell, in which the amount of fluorine ions eluted as a result of deterioration of electrolyte membrane components in particular is reduced, has excellent durability.

Claims

1. A reinforced electrolyte membrane for a fuel cell comprising a porous substrate impregnated with a polyelectrolyte liquid dispersion, wherein either the maximum tensile strength in the machine direction for sheet processing (MD) or the maximum tensile strength in the transverse direction (TD) vertical to the MD direction for the electrolyte membrane is 40 N/mm² or more at 80°

C. at a relative humidity of 90%,

wherein the relative elongation value is 0.4 to 1.0, provided that the value is obtained by designating, as a denominator, the larger of the degree of elongation in the machine direction (MD) and the degree of elongation in the transverse direction (TD) vertical to the MD direction at the maximum tensile strength of the electrolyte membrane.

2. The reinforced electrolyte membrane for a fuel cell according to claim 1, wherein the porous substrate is a polytetrafluoroethylene (PTFE) membrane made porous by stretching.

3. A fuel cell membrane-electrode assembly, which comprises a pair of electrodes comprising a fuel electrode to which fuel gas is supplied and an oxygen electrode to which an oxidizer gas is supplied and a polymer electrolyte membrane sandwiched between the pair of electrodes, wherein the polymer electrolyte membrane is the reinforced electrolyte membrane for fuel cell according to claim 1.

4. A solid polymer electrolyte fuel cell comprising a membrane-electrode assembly having the reinforced electrolyte membrane for fuel cell according to claim 1.

5. The fuel cell membrane-electrode assembly according to claim 3, wherein the porous substrate is a polytetrafluoroethylene (PTFE) membrane made porous by stretching.

6. The solid polymer electrolyte fuel cell according to claim 4, wherein the porous substrate is a polytetrafluoroethylene (PTFE) membrane made porous by stretching.