Layer system, bipolar plate comprising such a layer system, and fuel cell produced therewith

Patent metadata

Field	Value
Publication number	US-2023231151-A1
Application number	US-202017601175-A
Country	US
Kind code	A1
Filing date	Feb 21, 2020
Priority date	Apr 3, 2019
Publication date	Jul 20, 2023
Grant date	—

Abstract

A layer system ( 1 ) for coating a bipolar plate ( 2 ), including at least one cover layer ( 1 a ) made of tin oxide, wherein at least one metal oxide of the group comprising tantalum oxide, niobium oxide, titanium oxide, zirconium oxide, and hafnium oxide is homogenously dissolved in the tin oxide, and the electric conductivity of the cover layer ( 1 a ) is greater than or equal to 10 2 S/cm. A bipolar plate ( 2, 2 ′) is also provided with an anode side and a cathode side, comprising a substrate ( 2 a, 2 a ′) and such a layer system ( 1 ), and to a fuel cell ( 10 ) or an electrolyzer comprising such a bipolar plate ( 2, 2 ′).

First claim

1 . A layer system ( 1 ) for coating a bipolar plate ( 2 ), comprising at least one cover layer ( 1 a ) made of tin oxide, characterized in that at least one metal oxide of the group comprising tantalum oxide, niobium oxide, titanium oxide, zirconium oxide and hafnium oxide is homogeneously dissolved in the tin oxide, and in that the electric conductivity of the cover layer ( 1 a ) is greater than or equal to 10 2 S/cm.

2 . The layer system ( 1 ) according to claim 1 , characterized in that the cover layer ( 1 a ) is doped with iridium and/or ruthenium.

3 . The layer system ( 1 ) according to claim 2 , characterized in that the iridium and/or the ruthenium is present in the cover layer ( 1 a ) in a concentration in the range from 10 −4 at % to 0.1 at %.

4 . The layer system ( 1 ) according to one of the preceding claims, characterized in that an adhesive layer ( 1 c ) is also present in addition to the cover layer ( 1 a ), the adhesive layer ( 1 c ) having a layer thickness in the range from 1 nm to 300 nm.

5 . The layer system ( 1 ) according to claim 4 , characterized in that the adhesive layer ( 1 c ) is formed containing at least one element from the group comprising titanium, tantalum, niobium, zirconium and hafnium.

6 . The layer system ( 1 ) according to claim 4 or 5 , characterized in that between the cover layer ( 1 a ) and the adhesive layer ( 1 c ) there is arranged
at least one intermediate layer ( 1 b ) of a metal carbide or
at least one intermediate layer ( 1 b ) of a metal nitride or
at least one intermediate layer ( 1 b ) of a metal boride or
at least one intermediate layer ( 1 b ) comprising
at least one metal carbide and at least one metal nitride or
at least one metal carbide and at least one metal boride or
at least one metal nitride and at least one metal boride or
at least one metal carbide and at least one metal nitride and at least one metal boride or

a combination of two or more such intermediate layers ( 1 b ).

7 . The layer system ( 1 ) according to claim 6 , characterized in that the metal carbide and/or the metal nitride and/or the metal boride has at least one metal from the group comprising titanium, tantalum, niobium, zirconium and hafnium.

8 . The layer system ( 1 ) according to claim 7 , characterized in that the at least one metal is present in a concentration in the range from 30 to 56 at % in the metal carbide and/or metal nitride and/or metal boride.

9 . The layer system ( 1 ) according to one of claims 6 to 8 , characterized in that the at least one intermediate layer ( 1 b ) contains boron.

10 . The layer system ( 1 ) according to one of claims 1 to 9 , characterized in that the cover layer ( 1 a ) is doped with fluorine.

11 . The layer system ( 1 ) according to claim 10 , characterized in that the cover layer ( 1 a ) is further doped with nitrogen and/or carbon.

12 . A bipolar plate ( 2 , 2 ′) having an anode side and a cathode side, comprising a substrate ( 2 a, 2 a ′) and a layer system ( 1 ) according to one of claims 1 to 11 , having a structure of the bipolar plate in the following order:
substrate, in particular metallic substrate ( 2 a, 2 a ′),
gas diffusion layer ( 6 , 6 ′),
optional adhesive layer ( 1 c ),
optional intermediate layer(s) ( 1 b ),
cover layer ( 1 a ).

13 . A fuel cell ( 10 ), in particular an oxygen-hydrogen fuel cell, or electrolyzer, comprising at least one bipolar plate ( 2 , 2 ′) according to claim 12 .

14 . The fuel cell ( 10 ) according to claim 13 , comprising at least one polymer electrolyte membrane ( 7 ).

Assignees

• Schaeffler Technologies Ag

Inventors

• Wegener Moritz
• Vivekananthan Jeevanthi
• Musayev Yashar
• Dobrenizki Ladislaus
• Repenning Detlev

Classifications

• H01M8/0236 Primary

  Glass; Ceramics; Cermets · CPC title

• H01M8/0258

  characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant · CPC title

• H01M8/1018

  Polymeric electrolyte materials · CPC title

• H01M8/1004

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• C25B11/032

  Gas diffusion electrodes · CPC title