Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten

Definitions

• the invention relates to a fuel cell which comprises a membrane electrode assembly, two current collectors and / or a cell frame or a bipolar plate, at least one solid structural part being distinguished by the low weight and high corrosion resistance of the material used.
• EP 0 629 015 A1 discloses the following alloys or metals as materials for bipolar or collector plates: aluminum, titanium or alloys thereof, zirconium, niobium, tantalum or in turn alloys from one of these five elements. Furthermore, it is disclosed there that these elements can be passivated by protective electrically insulating oxides and that, as an alternative to the metals mentioned above, the plates can also be made of more corrosion-resistant materials such as graphite, high-alloy, stainless steel or nickel-chromium alloys. However, more precise information about the composition of well-suited alloys from these metals is not yet known. For mass production, the carbon materials are too heavy and too expensive to manufacture cell frames, current collectors and / or bipolar plates, etc. The metals in turn are too susceptible to corrosion and, because of their passivation due to the formation of an oxide layer, have too high losses during the transport of electricity within the fuel cell .
• the object of the present invention is therefore to provide a fuel cell suitable for mass production, in which the collector plates and / or cell frames and / or other structural parts of the fuel cell are made of a material which
• thermoforming quality
• the invention relates to a fuel cell which comprises a membrane electrode assembly, two current collectors and / or a cell frame and / or a bipolar plate, the material at least one of the solid structural parts being made of an Fe-based material which is made of the alloys with the following Compositions is selected:
• Fe is basically the main constituent of the alloy used according to the invention, the designation main constituent not being definable via percentages, but being seen relative to the other constituents.
• the present invention also relates to the use of an iron-based alloy with one of the abovementioned compositions in the construction of a fuel cell.
• the Fe-based material for the current collectors and / or the cell frame and / or the bipolar plate is preferably selected from the following alloys:
• the Fe-based material for the at least one solid structural part is selected from an alloy whose effective sum is> 26.9 and particularly preferably one whose effective sum is> 30.
• the Fe base material is additionally surface-treated in order to reduce the contact resistance.
• One possibility of such surface treatments is gilding or treatment e.g. with titanium nitride.
• the surface treatment can also be achieved by coating with conductive polymer plastics. In principle, all known surface treatments for reducing the contact resistance can be used here with the same or improved corrosion resistance.
• a “solid structural part” is understood to mean, for example, cell frames, current collectors and / or collector, bipolar, end and / or pole plates or another structural part, such as a frame element, etc., which is expediently obtained from a material that is dimensionally stable under normal conditions
• These can be angular, round, tubular and other structural parts, which in turn can have any embossed or otherwise formed surface structures, in which either cooling medium or reaction medium then flows or into which the membrane electrode unit flows is clamped in.
• a density element In practice, an axial channel or a tie rod or part of an axial channel or a tie rod can also be obtained from the material used according to the invention.
• any further construction material of a fuel cell can be selected from the alloys mentioned according to the invention.
• Fe-based materials have a small thickness of 20 to 300 ⁇ m, preferably 50 to 200 ⁇ m and particularly preferably approximately 100 ⁇ m. Under certain circumstances, completely different thicknesses of the plate may be appropriate for use as pole or end plates or other applications. Depending on the solid structural part for which the alloy is used according to the invention, the weight reduction of the fuel cell achieved by the invention naturally increases with the thickness of the part.
• pole plates and the end plates and the frame elements can be obtained from the materials in the fuel cells described in the abovementioned patent, which results in a significant weight reduction compared to the prior art.
• the invention is described below with reference to alloys used with preference:
• Alloy 1.4565 content of C 0 - 0.03% by weight content of Cr 23.0 - 25.0% by weight content of Mo 3.5 - 4.5% by weight content of Ni 16.0 - 18.0% by weight of Mn 5.0 - 6.5% by weight Content of N 0.4 - 0.5% by weight content of Nb 0 - 0.10% by weight content of Fe missing remainder to 100% by weight
• the materials mentioned according to the invention Lien also have a comparatively high corrosion resistance even when the plates and / or the frame elements come into direct contact with the acidic electrolyte. In addition, they have a good thermoforming quality and are therefore easy to form. Finally, they have a low contact resistance, which can be further optimized by appropriate surface treatment.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Fuel Cell (AREA)
• Inert Electrodes (AREA)
• Other Surface Treatments For Metallic Materials (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7818016

Family Applications (1)

Country Status (10)

Families Citing this family (24)

Family Cites Families (15)

• 1998
  • 1998-01-07 AT AT98904005T patent/ATE244933T1/de not_active IP Right Cessation
  • 1998-01-07 ES ES98904005T patent/ES2203926T3/es not_active Expired - Lifetime
  • 1998-01-07 DK DK98904005T patent/DK0963615T3/da active
  • 1998-01-07 CA CA002278490A patent/CA2278490C/fr not_active Expired - Fee Related
  • 1998-01-07 WO PCT/DE1998/000027 patent/WO1998033224A1/fr not_active Ceased
  • 1998-01-07 JP JP53146998A patent/JP2001508589A/ja active Pending
  • 1998-01-07 US US09/341,938 patent/US6300001B1/en not_active Expired - Fee Related
  • 1998-01-07 EP EP98904005A patent/EP0963615B1/fr not_active Revoked
  • 1998-01-07 DE DE59808983T patent/DE59808983D1/de not_active Revoked
• 1999
  • 1999-06-04 NO NO992738A patent/NO992738L/no not_active Application Discontinuation

Non-Patent Citations (1)

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